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W.D. Travis

Moderator of

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    MA12 - Miscellaneous Biology/Pathology (ID 476)

    • Event: WCLC 2016
    • Type: Mini Oral Session
    • Track: Biology/Pathology
    • Presentations: 11
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      MA12.01 - Next Generation Sequencing Based Clinical Framework for Analyses of Treatment Predictive Mutations and Gene Fusions in Lung Cancer (ID 4108)

      14:20 - 15:50  |  Author(s): K. Ericson Lindquist, A. Karlsson, P. Levéen, H. Brunnström, C. Reuterswärd, K. Holm, M. Jönsson, K. Annersten, F. Rosengren, K. Jirström, J. Kosieradzki, L. Ek, Å. Borg, M. Planck, G. Jönsson, J. Staaf

      • Abstract
      • Presentation
      • Slides

      Background:
      The use of new, emerging techniques in the search of tailored patient therapies is rapidly becoming a reality. Here we describe the optimization and implementation of next generation sequencing for treatment predictive mutation screening in parallel with gene fusion status of ALK, RET and ROS1 in non-small cell lung cancer (NSCLC) patients.

      Methods:
      The Illumina TruSight tumor 26-gene NGS panel was validated in 81 clinical routine FFPE or cytology specimens and implemented in 533 diagnostic NSCLCs during one year of clinical analysis. In parallel, a RNA-based NanoString method was evaluated in 169 cases for gene fusion status of ALK, RET and ROS1.

      Results:
      We have successfully established a streamlined workflow with a 5-day turnaround time from specimen arrival to mutation report. The concordance in the validation cohort was 99% for comparable variants. In the 533 diagnostic samples, 1-2 variants were detected in 79% of the cases. Most frequently mutated genes included TP53, KRAS, EGFR, STK11, and BRAF, all with differences in mutational patterns between histological subgroups. The RNA-based NanoString assay was successfully established and validated. The success rate in the 169 cases was 80% and 10 gene fusions were found (five ALK fusions, three RET fusions and two ROS1 fusions) all in adenocarcinomas. Integration of mutation and gene fusion status revealed that 68% of adenocarcinomas, 13% of SqCCs and 56% of NSCLC-NOS harbored ≥1 actionable alteration ALK, RET, ROS1, EGFR, KRAS, PIK3CA, BRAF, NRAS, MAP2K1, ERBB2 or AKT1. Specifically, in 13.2% of the adenocarcinomas where no EGFR or ALK alteration was detected emerging targeted therapy may be considered in addition to the 15.3% of patients that was eligible for EGFR or ALK inhibitors. The corresponding proportions for SqCCs were 5.5% in addition to the 2.2%, and for NSCLC-NOS 2.5% in addition to the 11.2% eligible for EGFR or ALK inhibitors.

      Conclusion:
      Next generation sequencing in combination with the NanoString technology is time- and cost efficient in the diagnostic routine for treatment predictive mutation screening and gene fusion status detection. The techniques represent valuable tools for pinpointing patients eligible to standard targeted therapies in addition to new emerging therapies.

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      MA12.02 - MMP12 and LMO7, Two Key Players on opposite Sides of Early Lung Squamous Cell Carcinoma Development (ID 5882)

      14:20 - 15:50  |  Author(s): A. Barrett, S. Lourenco, K. Kolluri, B. Carroll, M. Falzon, E. Borg, J. George, S.M. Janes, V.H. Teixeira

      • Abstract
      • Presentation
      • Slides

      Background:
      Our laboratory has a unique cohort of patients with pre-invasive lung squamous cell carcinoma (SqCC) lesions, within which there is a clear discrepancy between the prevalence of pre-invasive lesions and the incidence of lung cancer, suggesting that not all pre-invasive lesions progress to cancer. Using gene expression microarrays we identified 1846 genes significantly differentially expressed between progressive and regressive pre-invasive SqCC lesions. The macrophage metalloelastase MMP12 gene was found to be highly expressed in progressive lesions, and we hypothesised that it plays a role in epithelial-to-mesenchymal transition (EMT). Conversely, the actin binding protein LIM-domain only 7 (LMO7) gene was highly expressed in regressive lesions, and we postulated that it may be protective against EMT due to its role in the maintenance of epithelial architecture. Initial studies using three SqCC cell lines (A431, H357 and H376) with MMP12-shRNA knockdown showed a significant decrease in migration and invasion compared to non-silencing shRNA controls. LMO7-shRNA knockdown in HBECs was found to significantly increase migration. The aim of this study is to further characterise the function and signalling of MMP12 and LMO7 in lung SqCC development.

      Methods:
      Eight-week-old NOD/SCID mice were used for tumorigenesis experiments. A431 and H357 MMP12-shRNA knockdown and non-silencing shRNA cells were injected in a suspension of one million cells in a total of 200μl, subcutaneously in the right and left flank, respectively. Tumours were measured every 2–5 days. Adhesion assays were carried out to assess the roles of MMP12 knockdown or LMO7 overexpression on cell adhesion. Cell signalling mechanisms were assessed using western blotting, qPCR and immunostaining.

      Results:
      We observed that MMP12 knockdown decreases tumorigenicity in an immunocompromised mouse model. Both A431 and H357 MMP12 knockdown cells produced significantly smaller tumours compared with non-silencing shRNA cells. We found that MMP12 knockdown decreases cell adhesion, which is currently being further investigated along with effects on integrin signalling pathways. Levels of EMT markers were assessed in MMP12 knockdown and LMO7 overexpressing cells using qPCR, western blotting and immunostaining. Results indicate that higher MMP12 expression is associated with a mesenchymal phenotype, whereas higher LMO7 expression is associated with an epithelial phenotype.

      Conclusion:
      Our results suggest that MMP12 is a key driver of migration and invasion in SqCC and its high expression may contribute to EMT, whereas LMO7 is a putative tumour suppressor with a crucial role in maintaining epithelial cell architecture. MMP12 and LMO7 may be potential therapeutic markers for lung cancer at an early stage.

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      MA12.03 - Discussant for MA12.01, MA12.02 (ID 7010)

      14:20 - 15:50  |  Author(s): E. Brambilla

      • Abstract
      • Presentation
      • Slides

      Abstract not provided

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      MA12.04 - Mitochondrial-Related Proteins, PGAM5 and FUNDC1, in COPD-Associated Non-Small Cell Lung Carcinoma (ID 5646)

      14:20 - 15:50  |  Author(s): F. Kwong, A. Nicholson, I. Adcock, F. Chung

      • Abstract
      • Presentation
      • Slides

      Background:
      Patients with COPD and/or emphysema have an increased risk of non-small cell lung cancer (NSCLC). COPD and lung cancer are both characterised by increased oxidative stress associated with mitochondrial dysfunction. We hypothesise that mitochondrial dysfunction is a driving mechanism for the increased risk of NSCLC in COPD. We determined whether there is dysregulated expression of mitochondrial-related proteins in NSCLC arising in COPD, and if so, their clinical significance.

      Methods:
      To determine the clinical relevance of mitochondrial related gene expression, we examined a database containing transcriptomic data of more than 1, 000 human NSCLC samples and with survival outcomes (https://precog.stanford.edu/). Immunohistochemistry for PGAM5 and FUNDC1 was performed on cancer and background (‘normal’) tissue from lung cancer resections from non-smokers, healthy smokers (without COPD) and COPD/ emphysema patients. Protein expression was assessed using a semi-quantitative immunohistochemical scoring system (H score). Specific gene expression was further correlated with outcome in dataset GSE 72194, containing transcriptomic data of NSCLC cases and patient survival.

      Results:
      25 mitochondrial-related genes were linked to survival in NSCLC. Of those 25, we chose to study further the expression of PGAM5 and FUNDC1, which are regulators of mitochondrial degradation (mitophagy). In background lung tissue, PGAM5 and FUNDC1, only expressed in alveolar macrophages, were most highly expressed in COPD (H score: 180 ± 58 and 23 ± 9, respectively) compared to healthy smokers (146 ± 58 and 20 ± 8) and non-smokers (68 ± 48 and 3.3 ± 1.4) (p<0.05). In cancerous tissue, only the malignant epithelial cells and associated macrophages, at the periphery of the cancer, expressed PGAM5 and FUNDC1. PGAM5 was also expressed in pre-neoplastic epithelium (squamous dysplasia and carcinoma in situ). There was no difference in expression across the 3 groups, although the macrophages, at the edge of cancer, from COPD patients tended to show higher expression of PGAM5 and FUNDC1, compared to those from the other groups. When the expression of PGAM5 was compared with that of 50 known macrophage transcriptomic signatures within NSCLC samples, there was a positive correlation between PGAM5 and 9 macrophage signatures (r= 0.27 - 0.44, p<0.05), with one a determinant of patient survival.

      Conclusion:
      PGAM5 expression in pre-neoplastic tissue and NSCLC, but not in normal epithelium, suggests it plays a role in the transformation of malignant epithelial cells. PGAM5 and FUNDC1 may contribute to the pathogenesis of both COPD and NSCLC, possibly through mitophagic processes.

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      MA12.05 - Can Tumor Spread through Air Spaces (STAS) in Lung Adenocarcinomas Be Predicted Pre- and Intraoperatively? (ID 6026)

      14:20 - 15:50  |  Author(s): K. Kameda, S. Lu, T. Eguchi, N. Rekhtman, J.C. Chang, J. Montecalvo, D. Jones, W.D. Travis, P.S. Adusumilli

      • Abstract
      • Presentation
      • Slides

      Background:
      We and others have reported the prognostic impact of tumor spread through air spaces (STAS) in lung adenocarcinomas. The goal of this study is to investigate preoperative predicting factors for STAS and to determine whether STAS can be detected by intraoperative frozen section analysis.

      Methods:
      In a cohort of 874 patients with small (≤2cm) stage I adenocarcinoma (1995-2012), we reviewed preoperative computed tomography (CT) and positron emission tomography (PET) scans. According to the 2016 Fleischner Society’s criteria, radiological whole tumor size, consolidation size, as well as C/T ratio (consolidation/whole tumor diameter) were determined using thin slice (<3mm) CT scans where available (n=174). Clinico-radiological prediction of STAS was evaluated by logistic regression model. Using the frozen section slides with adequate adjacent lung parenchyma surrounding tumor without artifact (n=48), the presence of STAS was evaluated by five pathologists who are unaware of the radiological findings or the pathological information on permanent slides. The kappa statistic was calculated to measure the agreement between two pathologists.

      Results:
      In univariable model for predicting STAS, current smoker, larger consolidation tumor size, C/T ratio, and SUVmax were significant variables. In multivariable model, current smoker and C/T ratio were independent risk factors for the presence of STAS (p=0.027 and p<0.001, respectively; Table 1a). The sensitivity and the specificity of frozen section for prediction of STAS were 71% (95% confidence interval: 52-91%), 92.4% (81-100%) respectively, and the accuracy was 80% (71-89%). The kappa statistics were 0.40-0.74 (Table 1b) with 8/10 being moderate or substantial agreement.

      Conclusion:
      Smoking status and C/T ratio were independent predictors for the presence of STAS in patients with small lung adenocarcinomas. Frozen section prepared with adequate surrounding normal lung tissue may help identify STAS intraoperatively. Figure 1



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      MA12.06 - Tumor Spread through Air Spaces (STAS) in Lung Squamous Cell Cancer is an Independent Risk Factor: A Competing Risk Analysis (ID 6051)

      14:20 - 15:50  |  Author(s): S. Lu, T. Eguchi, K.S. Tan, S. Bains, K. Kadota, N. Rekhtman, P.S. Adusumilli, W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      Tumor spread through air spaces (STAS) is a recently recognized pattern of invasion in lung adenocarcinoma, however, the incidence of and prognostic importance of STAS have not yet been defined in squamous cell carcinoma (SCC).

      Methods:
      In a cohort of 445 patients with p-stage I-III lung SCC, cumulative incidence of recurrence and lung cancer-specific death (LCSD) was evaluated by competing risks analysis and overall survival (OS) by Cox models.

      Results:
      76% of patients were >65 years of age. 273 patients died during follow up, one third (91, 33.3%) died of lung cancer whereas two thirds died of competing events or unknown cause. STAS was present in 132 (30%). The cumulative incidence of any, distant, and locoregional recurrence as well as LCSD were significantly higher in patients with STAS compared to those without STAS (Figure), whereas there was no statistically significant difference in OS. STAS was an independent predictor for both recurrence and LCSD in multivariable analysis (p=0.034 and 0.016, respectively, Table).

      Conclusion:
      STAS was present in one third of resected lung SCC and it was an independent predictor of recurrence and LCSD, supporting our proposal that STAS is a clinically important pattern of invasion and not an artifact. Figure 1 Figure 2





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      MA12.07 - Discussant for MA12.04, MA12.05, MA12.06 (ID 7106)

      14:20 - 15:50  |  Author(s): E. Thunnissen

      • Abstract
      • Presentation
      • Slides

      Abstract not provided

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      MA12.08 - Clinicopathological Significance of Increasing Percentage of High-Grade Histological Subtypes in Lung Adenocarcinomas (ID 6023)

      14:20 - 15:50  |  Author(s): S. Lu, T. Eguchi, K.S. Tan, J.M. Isbell, D. Jones, W.D. Travis, P.S. Adusumilli

      • Abstract
      • Presentation
      • Slides

      Background:
      In early-stage lung adenocarcinomas, high-grade micropapillary (MIP) and solid (SOL) predominant pathology is known to be associated with worse prognosis. The aim of this study is, in addition to predominant patterns, to investigate clinical impact of the presence of small amounts (≥5%) as well as increasing percentage of high-grade patterns.

      Methods:
      Invasive tumors from early-stage lung adenocarcinoma patients who underwent curative-intent resection with no induction therapy were investigated (N=2017; 1995-2012) (8[th] edition TNM pStage I=1390, II=357, III=270). In 388 cases, synchronous lymph node (LN) metastases were available. Histological subtype (lepidic [LEP], acinar [ACI], papillary [PAP], MIP, or SOL) percentages were stratified into 4 groups; 0-4%, 5-24%, 25-49%, and 50-100%. The association between increasing percentage of patterns of primary tumor and the incidence of lymphatic/vascular invasion, necrosis, tumor spread through air spaces (STAS) as well as estimated 5-year cumulative incidence of recurrence (CIR) were analyzed. The differences in distribution of each pathological variable between 4 groups was analyzed by Chi-square test. The percentages of histological pattern were compared between primary tumor and LN metastasis.

      Results:
      Increasing percentage of MIP pattern is associated with increasing incidence of lymphatic/vascular invasion, STAS, as well as 5-year CIR (Figure 1a, p<0.001). Increasing percentage of SOL pattern is associated with increasing incidence of necrosis and 5-year CIR (p<0.001). Presence (≥5%) of SOL pattern is associated with higher incidence of lymphatic/vascular invasion and STAS (p<0.001) compared to the absence (<5%) of SOL pattern, but no significant relationship between lymphatic/vascular invasion and proportion of SOL pattern. The percentage of SOL pattern in LN metastasis is higher than that in synchronous primary tumors (Figure 1b).

      Conclusion:
      In early-stage lung adenocarcinomas, presence (≥5%) of MIP or SOL patterns as well as increasing percentages is associated with poor prognostic clinicopathological variables and incidence of recurrence. Figure 1



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      MA12.09 - Comparative Histological Subtype Analysis of Lung Adenocarcinoma Tumor and Metastatic Lymph Nodes and the Prognostic Impact (ID 6036)

      14:20 - 15:50  |  Author(s): S. Lu, T. Eguchi, Z. Tano, D. Molena, D. Jones, W.D. Travis, P.S. Adusumilli

      • Abstract
      • Presentation
      • Slides

      Background:
      The goal of this study is to investigate comprehensive comparative pathological analyses of both primary tumor and metastatic lymph node (LN) and correlate with lung cancer-specific death (LC-death) in patients with LN-positive lung adenocarcinoma.

      Methods:
      PN1/2 lung adenocarcinoma patients who underwent R0 resection without induction therapy (n=402, 2000-2012) were included in the study. In primary tumor, lymphatic/vascular/pleural invasion, necrosis, tumor spread through air spaces (STAS), as well as histologic subtypes according to 2015 WHO classification were evaluated. In metastatic LN, metastatic tumor size, extracapsular invasion, histologic subtypes were evaluated. Recurrence and LC-death were analyzed by Cox model.

      Results:
      Micropapillary and solid predominant subtypes were more frequent in LN metastases than in primary tumors (Figure). In multivariable analyses, adjuvant chemotherapy, pleural invasion, extracapsular invasion of LN metastasis, micropapillary predominant subtype in LN metastasis were independent factors for recurrence; adjuvant chemotherapy, pleural invasion, tumor STAS, and extracapsular invasion were for LC-death (Table).

      Conclusion:
      In lung adenocarcinoma lymph node metastases, predominant micropapillary pattern and extracapsular invasion indicate high risk for recurrence and lung cancer-specific death. Figure 1 Figure 2





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      MA12.10 - Histological Subtyping of Matched Primary and Metastases Sites in Lung Adenocarcinoma: Significance of Solid Predominance (ID 5767)

      14:20 - 15:50  |  Author(s): Y. Takahashi, T. Eguchi, S. Lu, R.J. Downey, D. Jones, W.D. Travis, P.S. Adusumilli

      • Abstract
      • Presentation
      • Slides

      Background:
      Clinical significance of 2015 WHO classification histological subtype of early-stage lung adenocarcinoma (LADC) has been well documented; the incidence and significance of histological subtypes in autologous metastatic tumors is unknown.

      Methods:
      Histological subtyping was performed on paired primary and metastatic LADC tumor samples from patients who underwent resection of metastases (N=203, 1996-2012). 57 cases with inadequate tumor specimen and 4 cases diagnosed as local recurrence were excluded.

      Results:
      Location of metastatic sites were – brain 51 (35.9%), lung 48 (33.8%), lymph node 14 (9.9%), pleura 10 (7.0%), and adrenal gland 5 (3.5%). Metastatic tumors demonstrated more frequent solid histological pattern than primary tumors (first predominance: 51% vs. 24%; second predominance 29% vs. 17%, Figure 1). Among all histological subtypes, solid subtype showed the highest concordance between primary and metastatic tumors (Figure 2). In addition, analysis of all available clinicopathological factors showed significantly higher percentage of solid subtype in both primary and metastatic tumors was observed in patients with smoking history (p=0.003 and p=0.004, respectively).

      Conclusion:
      Analysis of a large cohort of primary and autologous metastatic LADC tumors demonstrated a higher percentage of solid histological pattern metastases, even in cancers with a low solid component in the primary site of disease. Figure 1Figure 2





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      MA12.11 - Discussant for MA12.08, MA12.09, MA12.10 (ID 6951)

      14:20 - 15:50  |  Author(s): W.A. Cooper

      • Abstract
      • Presentation
      • Slides

      Abstract not provided

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Author of

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    ED07 - Classification and Druggable Targets of Thoracic Tumors (ID 272)

    • Event: WCLC 2016
    • Type: Education Session
    • Track: Biology/Pathology
    • Presentations: 1
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      ED07.01 - Adenocarcinomas and Squamous Cell Carcinomas (ID 6457)

      11:00 - 12:30  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Abstract not provided

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    MA11 - Novel Approaches in SCLC and Neuroendocrine Tumors (ID 391)

    • Event: WCLC 2016
    • Type: Mini Oral Session
    • Track: SCLC/Neuroendocrine Tumors
    • Presentations: 1
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      MA11.07 - Improved Small Cell Lung Cancer (SCLC) Response Rates with Veliparib and Temozolomide: Results from a Phase II Trial (ID 5517)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      PARP1 is overexpressed in small cell lung cancer (SCLC) and represents a novel therapeutic target for this disease. Preclinical data indicates that combining veliparib (an oral PARP-1/2 inhibitor) and temozolomide (TMZ) results in synergistic tumor growth delay or regression. In this study, we investigated whether adding veliparib to TMZ would improve outcomes in patients with relapsed sensitive and refractory SCLCs. Candidate predictive biomarkers, including SLFN11, were then explored.

      Methods:
      SCLC patients previously treated with 1 or 2 prior regimens were enrolled in the trial and randomized 1:1 to receive oral TMZ 150-200mg/m[2]/day (D1-5) with either veliparib or placebo 40mg twice daily, orally (D1-7) (NCT01638546). Primary endpoint was 4-month progression free survival (PFS). Data were analyzed in patients with platinum sensitive (progression >60 days after 1st line therapy) or refractory disease (progression ≤60 days after 1st line therapy, or in need of 3rd line treatment). Archived tissue was available for 53 patients for biomarker analysis.

      Results:
      104 patients were enrolled and 100 patients were treated. Baseline characteristics were balanced between treatment arms: 52% female; median age 62.5 (range, 31-84); 59% refractory disease; 33% needing 3rd-line therapy. Progression free survival at 4-months was similar between the two arms, 36% vs. 27% (p=0.39). However, in 93 evaluable pts, response rate was significantly higher in pts treated with veliparib/TMZ compared to TMZ alone (39% vs 14%, p =0.016). Median overall survival: 8.2 mos (95% CI: 6.4-12.2) in veliparib arm and 7 mos (95% CI: 5.3-9.5) in placebo arm, p = 0.50. Grade 3/4 thrombocytopenia and neutropenia more commonly occurred in the veliparib/TMZ arm: 50% vs 9% and 31% vs 7%, respectively. Levels of SLFN11, a marker of SCLC response to PARP inhibition in preclinical models, were assessed by immunohistochemistry. High SLFN11 in patient tumors (obtained at original diagnosis) was associated with a trend towards better overall survival in the veliparib/TMZ arm, but no difference in outcome in the TMZ alone arm. Additional correlative studies are ongoing, including assessment of MGMT promoter methylation, and will be available at the time of presentation.

      Conclusion:
      The combination of veliparib/TMZ increased response rates significantly, compared to TMZ alone. Hematologic toxicities of the combination may have impacted PFS (which was not significantly different between the arms) by limiting dosing. Biomarkers such as SLFN11, ATM, or MGMT promoter methylation could potentially help guide patient selection in the SCLC population.

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    MA12 - Miscellaneous Biology/Pathology (ID 476)

    • Event: WCLC 2016
    • Type: Mini Oral Session
    • Track: Biology/Pathology
    • Presentations: 5
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      MA12.05 - Can Tumor Spread through Air Spaces (STAS) in Lung Adenocarcinomas Be Predicted Pre- and Intraoperatively? (ID 6026)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      We and others have reported the prognostic impact of tumor spread through air spaces (STAS) in lung adenocarcinomas. The goal of this study is to investigate preoperative predicting factors for STAS and to determine whether STAS can be detected by intraoperative frozen section analysis.

      Methods:
      In a cohort of 874 patients with small (≤2cm) stage I adenocarcinoma (1995-2012), we reviewed preoperative computed tomography (CT) and positron emission tomography (PET) scans. According to the 2016 Fleischner Society’s criteria, radiological whole tumor size, consolidation size, as well as C/T ratio (consolidation/whole tumor diameter) were determined using thin slice (<3mm) CT scans where available (n=174). Clinico-radiological prediction of STAS was evaluated by logistic regression model. Using the frozen section slides with adequate adjacent lung parenchyma surrounding tumor without artifact (n=48), the presence of STAS was evaluated by five pathologists who are unaware of the radiological findings or the pathological information on permanent slides. The kappa statistic was calculated to measure the agreement between two pathologists.

      Results:
      In univariable model for predicting STAS, current smoker, larger consolidation tumor size, C/T ratio, and SUVmax were significant variables. In multivariable model, current smoker and C/T ratio were independent risk factors for the presence of STAS (p=0.027 and p<0.001, respectively; Table 1a). The sensitivity and the specificity of frozen section for prediction of STAS were 71% (95% confidence interval: 52-91%), 92.4% (81-100%) respectively, and the accuracy was 80% (71-89%). The kappa statistics were 0.40-0.74 (Table 1b) with 8/10 being moderate or substantial agreement.

      Conclusion:
      Smoking status and C/T ratio were independent predictors for the presence of STAS in patients with small lung adenocarcinomas. Frozen section prepared with adequate surrounding normal lung tissue may help identify STAS intraoperatively. Figure 1



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      MA12.06 - Tumor Spread through Air Spaces (STAS) in Lung Squamous Cell Cancer is an Independent Risk Factor: A Competing Risk Analysis (ID 6051)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      Tumor spread through air spaces (STAS) is a recently recognized pattern of invasion in lung adenocarcinoma, however, the incidence of and prognostic importance of STAS have not yet been defined in squamous cell carcinoma (SCC).

      Methods:
      In a cohort of 445 patients with p-stage I-III lung SCC, cumulative incidence of recurrence and lung cancer-specific death (LCSD) was evaluated by competing risks analysis and overall survival (OS) by Cox models.

      Results:
      76% of patients were >65 years of age. 273 patients died during follow up, one third (91, 33.3%) died of lung cancer whereas two thirds died of competing events or unknown cause. STAS was present in 132 (30%). The cumulative incidence of any, distant, and locoregional recurrence as well as LCSD were significantly higher in patients with STAS compared to those without STAS (Figure), whereas there was no statistically significant difference in OS. STAS was an independent predictor for both recurrence and LCSD in multivariable analysis (p=0.034 and 0.016, respectively, Table).

      Conclusion:
      STAS was present in one third of resected lung SCC and it was an independent predictor of recurrence and LCSD, supporting our proposal that STAS is a clinically important pattern of invasion and not an artifact. Figure 1 Figure 2





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      MA12.08 - Clinicopathological Significance of Increasing Percentage of High-Grade Histological Subtypes in Lung Adenocarcinomas (ID 6023)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      In early-stage lung adenocarcinomas, high-grade micropapillary (MIP) and solid (SOL) predominant pathology is known to be associated with worse prognosis. The aim of this study is, in addition to predominant patterns, to investigate clinical impact of the presence of small amounts (≥5%) as well as increasing percentage of high-grade patterns.

      Methods:
      Invasive tumors from early-stage lung adenocarcinoma patients who underwent curative-intent resection with no induction therapy were investigated (N=2017; 1995-2012) (8[th] edition TNM pStage I=1390, II=357, III=270). In 388 cases, synchronous lymph node (LN) metastases were available. Histological subtype (lepidic [LEP], acinar [ACI], papillary [PAP], MIP, or SOL) percentages were stratified into 4 groups; 0-4%, 5-24%, 25-49%, and 50-100%. The association between increasing percentage of patterns of primary tumor and the incidence of lymphatic/vascular invasion, necrosis, tumor spread through air spaces (STAS) as well as estimated 5-year cumulative incidence of recurrence (CIR) were analyzed. The differences in distribution of each pathological variable between 4 groups was analyzed by Chi-square test. The percentages of histological pattern were compared between primary tumor and LN metastasis.

      Results:
      Increasing percentage of MIP pattern is associated with increasing incidence of lymphatic/vascular invasion, STAS, as well as 5-year CIR (Figure 1a, p<0.001). Increasing percentage of SOL pattern is associated with increasing incidence of necrosis and 5-year CIR (p<0.001). Presence (≥5%) of SOL pattern is associated with higher incidence of lymphatic/vascular invasion and STAS (p<0.001) compared to the absence (<5%) of SOL pattern, but no significant relationship between lymphatic/vascular invasion and proportion of SOL pattern. The percentage of SOL pattern in LN metastasis is higher than that in synchronous primary tumors (Figure 1b).

      Conclusion:
      In early-stage lung adenocarcinomas, presence (≥5%) of MIP or SOL patterns as well as increasing percentages is associated with poor prognostic clinicopathological variables and incidence of recurrence. Figure 1



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      MA12.09 - Comparative Histological Subtype Analysis of Lung Adenocarcinoma Tumor and Metastatic Lymph Nodes and the Prognostic Impact (ID 6036)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      The goal of this study is to investigate comprehensive comparative pathological analyses of both primary tumor and metastatic lymph node (LN) and correlate with lung cancer-specific death (LC-death) in patients with LN-positive lung adenocarcinoma.

      Methods:
      PN1/2 lung adenocarcinoma patients who underwent R0 resection without induction therapy (n=402, 2000-2012) were included in the study. In primary tumor, lymphatic/vascular/pleural invasion, necrosis, tumor spread through air spaces (STAS), as well as histologic subtypes according to 2015 WHO classification were evaluated. In metastatic LN, metastatic tumor size, extracapsular invasion, histologic subtypes were evaluated. Recurrence and LC-death were analyzed by Cox model.

      Results:
      Micropapillary and solid predominant subtypes were more frequent in LN metastases than in primary tumors (Figure). In multivariable analyses, adjuvant chemotherapy, pleural invasion, extracapsular invasion of LN metastasis, micropapillary predominant subtype in LN metastasis were independent factors for recurrence; adjuvant chemotherapy, pleural invasion, tumor STAS, and extracapsular invasion were for LC-death (Table).

      Conclusion:
      In lung adenocarcinoma lymph node metastases, predominant micropapillary pattern and extracapsular invasion indicate high risk for recurrence and lung cancer-specific death. Figure 1 Figure 2





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      MA12.10 - Histological Subtyping of Matched Primary and Metastases Sites in Lung Adenocarcinoma: Significance of Solid Predominance (ID 5767)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      Clinical significance of 2015 WHO classification histological subtype of early-stage lung adenocarcinoma (LADC) has been well documented; the incidence and significance of histological subtypes in autologous metastatic tumors is unknown.

      Methods:
      Histological subtyping was performed on paired primary and metastatic LADC tumor samples from patients who underwent resection of metastases (N=203, 1996-2012). 57 cases with inadequate tumor specimen and 4 cases diagnosed as local recurrence were excluded.

      Results:
      Location of metastatic sites were – brain 51 (35.9%), lung 48 (33.8%), lymph node 14 (9.9%), pleura 10 (7.0%), and adrenal gland 5 (3.5%). Metastatic tumors demonstrated more frequent solid histological pattern than primary tumors (first predominance: 51% vs. 24%; second predominance 29% vs. 17%, Figure 1). Among all histological subtypes, solid subtype showed the highest concordance between primary and metastatic tumors (Figure 2). In addition, analysis of all available clinicopathological factors showed significantly higher percentage of solid subtype in both primary and metastatic tumors was observed in patients with smoking history (p=0.003 and p=0.004, respectively).

      Conclusion:
      Analysis of a large cohort of primary and autologous metastatic LADC tumors demonstrated a higher percentage of solid histological pattern metastases, even in cancers with a low solid component in the primary site of disease. Figure 1Figure 2





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    OA07 - Lymph Node Metastases and Other Prognostic Factors for Local Spread (ID 376)

    • Event: WCLC 2016
    • Type: Oral Session
    • Track: Surgery
    • Presentations: 1
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      OA07.06 - In Early-Stage Lung Adenocarcinomas, Survival by Tumor Size (T) is Further Stratified by Tumor Spread through Air Spaces (ID 5905)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      We investigated whether tumor spread through air spaces (STAS) further stratifies survival beyond tumor size, T-descriptor independent of resection type (lobectomy or limited resection) and surgical margin.

      Methods:
      In patients with pT1a-T2bN0M0 lung adenocarcinomas (LADC, n=1399), tumor size, distance of STAS from the tumor, type of resection, surgical margin were evaluated. The patients with small (≤2cm) tumors were divided into STAS(-) (n=561) and STAS(+) (n=307) and their cumulative incidence of recurrence (CIR), and lung cancer-specific death (CID) were compared with patients with larger tumors (2-3cm, n=299) by use of competing risk analysis.

      Results:
      Of 1399 tumors, 521 (37%) were STAS(+). Compared to STAS(-), recurrence rates were higher with STAS(+) tumors even when the margin is ≥tumor size (Figure 1). In patients with ≤2cm STAS(+) tumors, CIR and CID are higher than in patients with larger (2-3cm) tumors (Figure 2). The poor prognostic influence of STAS(+) was evident even when analyzed by the procedure or recurrence pattern (Figure 2 table).

      Conclusion:
      STAS further stratifies survival beyond tumor size, T-descriptor in early-stage (pT1a-2b) lung adenocarcinoma based on the higher prognostic potential for recurrence and lung cancer-specific death independent of the type of resection or margin. Figure 1 Figure 2





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    OA24 - Radiotherapy of Lung Cancer: Recent Developments (ID 411)

    • Event: WCLC 2016
    • Type: Oral Session
    • Track: Radiotherapy
    • Presentations: 1
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      OA24.06 - Histologic Subtype of Early-Stage Lung Adenocarcinoma is a Predictor of Failure Patterns after Stereotactic Body Radiation Therapy (ID 4618)

      14:20 - 15:50  |  Author(s): W.D. Travis

      • Abstract
      • Presentation
      • Slides

      Background:
      Stereotactic body radiation therapy (SBRT) has emerged as an effective treatment for early-stage lung cancer. Histologic subtyping in surgically resected lung adenocarcinomas is recognized as a prognostic factor, with the presence of solid or micropapillary patterns predicting poor outcomes. Herein, we describe outcomes following SBRT for early-stage lung adenocarcinoma by histologic subtype.

      Methods:
      We identified 119 consecutive patients (124 lesions) with stage I-IIA lung adenocarcinoma who were treated with definitive SBRT at our institution between August 2008 and August 2015 and had undergone core biopsy. Histologic subtyping was performed according to the 2015 WHO Classification. Thirty-seven tumors (30%) were of high risk subtype, defined as containing a component of solid and/or micropapillary pattern. Cumulative incidences of local, nodal, regional and distant failure were compared between high risk vs. non-high risk adenocarcinoma subtypes with Gray’s test, and multivariable-adjusted hazard ratios were estimated from propensity score-weighted Cox regression models.

      Results:
      Median follow-up for the entire cohort was 17 months and 21 months for surviving patients. The 1-year cumulative incidence of local, nodal, regional and distant failure, respectively, in high risk and non-high risk lesions were 7.3%, 14.8%, 4.0%, 22.7% and 2.7%, 2.6%, 1.2%, 3.6%. Hazard ratios for local, nodal, regional and distant failure, respectively, of high risk lesions compared to non-high risk were 16.8 (95% CI 3.5-81.4), 3.8 (95% CI 0.95-15.0), 20.9 (95% CI 2.3-192.3), 6.9 (95% CI 2.2-21.1). No significant difference was seen with regard to overall survival.

      Conclusion:
      Outcomes following SBRT for early-stage adenocarcinoma of the lung are highly correlated with histologic subtype, with micropapillary and solid tumors portending significantly higher rates of locoregional and metastatic progression. In this context, histologic subtype based on core biopsies is a novel prognostic factor and may have important implications for patient selection, adjuvant treatment, biopsy methods and clinical trial design.

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    P1.03 - Poster Session with Presenters Present (ID 455)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Radiology/Staging/Screening
    • Presentations: 1
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      P1.03-084 - Implications of 8th Edition TNM Proposal: Invasive vs. Total Size for T Descriptor in pT1a-2bN0M0 Lung Adenocarcinoma (ID 5788)

      14:30 - 15:45  |  Author(s): W.D. Travis

      • Abstract
      • Slides

      Background:
      The aim of this study was to conduct a clinicopathological comparative analysis of total tumor versus invasive tumor size in pT1a-2bN0M0 nonmucinous lung adenocarcinomas.

      Methods:
      Resected pT1a-2bN0M0 lung adenocarcinomas (1995-2012) based on 8th edition of TNM classification using total (N=1475) and invasive tumor size (N=1482) were included. Recurrence free probability [RFP] and lung cancer-specific survival [LCSS]) were compared between both pT-staging systems using Kaplan-Meier method.

      Results:
      Use of invasive size for the T descriptor increased the number of pT1a tumors by 2 fold compared to use of total tumor size (316 vs. 161), with no difference in RFP and LCSS (RFP, 82% vs. 80%; LCSS, 94% vs. 93%). Use of invasive rather than total size also showed better stratification of lymphatic/vascular invasion and high-grade histological subtypes according to increasing pT stage. RFP and LCSS in invasive-size-based pT2b were lower than those in total-size-based pT2b (RFP, 44% vs. 60%; LCSS, 69% vs. 77%).

      Conclusion:
      In pT1a-2bN0M0 nonmucinous lung adenocarcinoma, the 8th edition TNM proposal to use invasive rather than total size for the pT descriptor gives better prognostic discrimination by capturing a larger number of patients with favorable prognosis (pT1a) and providing better stratification for pT2b. Figure 1 Figure 2





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    P3.01 - Poster Session with Presenters Present (ID 469)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Biology/Pathology
    • Presentations: 2
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      P3.01-021 - Reproducibility of Comprehensive Histologic Assessment and Refining Histologic Criteria in P Staging of Multiple Tumour Nodules (ID 5365)

      14:30 - 15:45  |  Author(s): W.D. Travis

      • Abstract
      • Slides

      Background:
      Multiple tumor nodules (MTNs) are being encountered, with increasing frequency with the 8[th] TNM staging system recommending classification as separate primary lung cancers (SPLC) or intrapulmonary metastases (IM). Pathological staging requires assessment of morphological features, with criteria of Martini and Melamed supplanted by comprehensive histologic assessment of tumour type, predominant pattern, other histologic patterns and cytologic features. With publication of the 2015 WHO classification of lung tumours, we assessed the reproducibility of comprehensive histologic assessment and also sought to identify the most useful histological features.

      Methods:
      We conducted an online survey in which pathologists reviewed a sequential cohort of resected multifocal tumours to determine whether they were SPLC, IM, or a combination. Specific histological features for each nodule were entered into the database by the observing pathologist (tumour type, predominant adenocarcinoma pattern, and histological features including presence of lepidic growth, intra-alveolar cell clusters, cell size, mitotic rate, nuclear pleomorphism, nucleolar size and pleomorphism, nuclear inclusions, necrosis pattern, vascular invasion, mucin content, keratinization, clear cell change, cytoplasmic granules¸ lymphocytosis, macrophage response, acute inflammation and emperipolesis). Results were statistically analyzed for concordance with submitting diagnosis (gold standard) and among pathologists. Consistency of each feature was correlated with final determination of SPLC vs. IM status (p staging) by chi square analysis and Fisher exact test.

      Results:
      Seventeen pathologists evaluated 126 tumors from 48 patients. Kappa score on overall assessment of primary v. metastatic status was 0.60. There was good agreement as measured by Cohen’s Kappa (0.64, p<0.0001) between WHO histological patterns in individual cases with SPLC or IM status but proportions for histology and SPT or IM status were not identical (McNemar's test, p<0.0001) and additional histological features were assessed. There was marked variation in p values among the specific histological features. The strongest correlations (<0.05) between p staging status and histological features were with nuclear pleomorphism, cell size, acinus formation, nucleolar size, mitotic rate, nuclear inclusions, intra-alveolar clusters and necrosis pattern. Correlation between lymphocytosis, mucin content, lepidic growth, vascular invasion, macrophage response, clear cell change, acute inflammation keratinization and emperipolesis did not reach a p value of 0.05.

      Conclusion:
      Comprehensive histologic assessment shows good reproducibility between practicing lung pathologists. In addition to main tumour type and predominant patterns, nuclear pleomorphism, cell size, acinus formation, nucleolar size, and mitotic rate appear to be useful in distinguishing between SPLC and IM.

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      P3.01-029 - Cases Demonstrating Spread Through Air Spaces (STAS) Reflects Invasive Growth and Not an Artifact (ID 6059)

      14:30 - 15:45  |  Author(s): W.D. Travis

      • Abstract
      • Slides

      Background:
      STAS is defined as a pattern of tumor cell spread in the lung parenchyma beyond the edge of a lung cancer. It has been postulated that this is an ex vivo artifact due to the force of knife with the premise that STAS is clinically unimportant and it should be ignored like true artifacts.

      Methods:
      We present three cases providing evidence that STAS is not an artifact and is clinically relevant.

      Results:
      Case 1: 68F underwent wedge resection of a left upper lobe (LUL) lung adenocarcinoma. During the surgical procedure the surgeon did not cut across the tumor, but sent a separate wedge biopsy as an additional margin. The latter wedge contained an 8 mm focus of adenocarcinoma consisting almost entirely of a STAS pattern with a 1mm area of acinar growth. Case 2: 66M underwent RUL wedge resection in August 2013 for a 1.3 cm lung adenocarcinoma. The resection margin was positive with only STAS in the margin. In the absence of any clinical sign of recurrence or metastases, a completion right upper lobectomy was performed revealing three separate foci of residual adenocarcinoma including 1.5 and 1.0 mm acinar areas and a 0.5 mm focus of STAS with N1 and N2 lymph node metastases. Adjuvant chemotherapy and radiation were given. In 2014, the patient developed multiple bilateral nodules and in November underwent LUL wedge resection that showed three foci of adenocarcinoma with a STAS predominant pattern. In July 2016, the patient remains on chemotherapy with slowly growing bilateral nodules. Case 3: A 77M presented with pneumonia and bilateral ground glass opacities with focal consolidation. A biopsy, originally interpreted as benign, showed diffuse involvement by adenocarcinoma with a STAS predominant pattern. The morphology does not explain the consolidation seen on CT indicating the surgeon did not cut across the main tumor area.

      Conclusion:
      We present three cases which provide evidence that STAS is not an artifact that should be ignored. In two cases the extensive STAS predominant pattern was not a knife cutting artifact because the main tumor was not cut either by the surgeon or pathologist. In the third case, STAS was the only pattern of tumor identified at a wedge resection margin. If this had been ignored, the residual and metastatic tumor would not have been identified delaying introduction of chemotherapy. These findings support the concept that STAS is a clinically important invasive pattern and not an artifact.

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