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N. Rekhtman



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    MO13 - SCLC I (ID 118)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Medical Oncology
    • Presentations: 1
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      MO13.10 - Prospective Molecular Evaluation of Small Cell Lung Cancer (SCLC) Utilizing the Comprehensive Mutation Analysis Program at Memorial Sloan-Kettering Cancer Center (MSKCC) (ID 3137)

      10:30 - 12:00  |  Author(s): N. Rekhtman

      • Abstract
      • Presentation
      • Slides

      Background
      Oncogenic events in adenocarcinoma and squamous cell cancers of the lung are well described. In contrast, the repertoire of possible molecular targets in SCLC still is unclear. Recent studies using next generation sequencing on rare resected SCLC specimens have provided insights into the molecular heterogeneity of this disease. Comprehensive, prospective molecular profiling of patients with SCLC using the biopsy specimens available in clinical practice has not been performed.

      Methods
      Utilizing an IRB-approved protocol to prospectively test SCLC tumors (Small Cell Lung Cancer Mutation Analysis Program, “SCLC-MAP”), these biopsies are evaluated by: FISH for FGFR1 and MET amplification; immunohistochemistry (IHC) for MGMT and PTEN loss; point mutation genotyping with Sequenom for PIK3CA (and others); and next-generation sequencing with our MSK-IMPACT assay (Integrated Mutation Profiling of Actionable Cancer Targets). MSK-IMPACT uses exon capture followed by massively parallel sequencing to profile all protein-coding exons and select introns of 279 cancer-associated genes, enabling the identification of mutations, indels, and copy number alterations of these genes. First, we tested the feasibility of this approach in a series of SCLC patients that were identified retrospectively as they had banked matched tumor and normal pairs. We performed next generation sequencing with MSK-IMPACT, with findings confirmed by FISH on these samples. We are prospectively collecting and evaluating SCLC tumors of our patients in active treatment, as detailed above.

      Results
      For our feasibility cohort, we identified 21 patients with SCLC with FFPE samples available from both matched normal tissue and small tumor biopsies. After histologic review and DNA extraction, 10 patients had adequate tissue for MSK-IMPACT (3 core biopsies, 7 fine needle aspirates). The following were noted: recurrent mutations in Rb1 (N=7) and p53 (N=8), FGFR1 amplification (N=2), and MET amplification (N=1), using as little as 15 nanograms of DNA. FGFR1 and MET amplification were confirmed by FISH testing. We have initiated this prospective SCLC-MAP program for our SCLC patients undergoing active treatment. Since 2/2013, 25 patients have provided consent and tumor tissue for analysis (8 surgical resections, 12 core biopsies, 3 lymph node dissections, 2 fine needle aspirates). Preliminary data are available for 16 patients: AKT1 E17 mutation by Sequenom (N=1), MGMT loss by IHC (N=1); and PTEN loss by IHC (N=2).

      Conclusion
      As adequate biopsy specimens are necessary to match lung cancer patients and treatments, increased number of patients with SCLC are presenting with more tissue. Comprehensive molecular evaluation of SCLC is feasible on clinically available specimens, as seen in our feasibility cohort. Prospective collection of SCLC tumor samples and mutational analyses are ongoing. Such analyses will allow us to characterize the molecular diversity of this disease and identify patients who will be candidates for targeted therapies. Funded, in part, by the Lung Cancer Research Foundation.

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    MO16 - Prognostic and Predictive Biomarkers IV (ID 97)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Medical Oncology
    • Presentations: 1
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      MO16.09 - Patterns of metastasis and survival in patients with PI3K-aberrant and FGFR1 amplified stage IV squamous cell lung cancers (SQCLCs) (ID 1666)

      16:15 - 17:45  |  Author(s): N. Rekhtman

      • Abstract
      • Presentation
      • Slides

      Background
      The majority of actionable drivers in SQCLCs occur in the PI3K (30%) and FGFR1 (20%) pathways. The biologic behaviors and natural histories of these subtypes are not well characterized. Characterization of these data may help to elucidate the biologic relevance of these putative oncogenic events.

      Methods
      As of October 2011, all patients with SQCLCs at MSK have undergone prospective, multiplex testing of their FFPE tumors for FGFR1 amplification (FISH, FGFR1:CEP8 ≥ 2.2), PIK3CA mutations (Sequenom and exon sequencing), PTEN loss (IHC, Cell Signaling), and PTEN mutations (exon sequencing), among others. The PI3K abberant group was defined as PIK3CA mutant, PTEN complete loss, or PTEN mutant. Patient characteristics, outcomes, and metastatic sites were identified. Survival probabilities were estimated using the Kaplan-Meier method. Group comparisons were performed with log-rank tests and Cox proportional hazards methods.

      Results
      77 stage IV SQCLC patients were analyzed. Genotypes were: FGFR1 amplified (23%); PTEN loss (22%), PIK3CA mutant (8%), PTEN mutant (7%). Events were non-overlapping save for 2 cases with PTEN nonsense mutations and PTEN loss. The sole significant clinical difference (KPS, age, sex, lines of tx, smoking status) was sex (women in PI3K group 52% vs. in others 23%, p=0.02). Metastatic patterns for PI3K and FGFR1 vs. all others were:

      Site PI3K p FGFR1 p Other Total
      Brain 6 (22%) 0.002 0 (0%) 0.6 0 (0%) 6 (7%)
      Pleura 5 (19%) 0.4 5 (28%) 0.7 9 (28%) 19 (25%)
      Liver 5 (19%) 0.4 1 (6%) 1 1 (3%) 7 (9%)
      Bone 8 (30%) 0.8 3 (17%) 0.7 10 (31%) 21 (27%)
      Lung 12 (44%) 0.8 10 (56%) 0.2 12 (38%) 34 (44%)
      Adrenal 3 (11%) 1 3 (17%) 1 4 (13%) 10 (13%)
      Pericardium 1 (4%) 1 1 (6%) 0.3 0 2 (3%)
      Median OS for PI3K vs. all others: 9mo (95%CI:8-NR) vs. 16mo (95%CI:11-NR), p=0.004. Median OS for FGFR1 vs. all others: 20mo (95%CI:11-NR) vs. 10mo (95%CI:9-16), p=0.06. Multivariate analysis for risk of death: PI3K HR=3.3 (95%CI:1.5-7, p=0.003); FGFR1 HR=0.5 (95%CI:0.2-1.1, p=0.06); Age ≥65, HR=1.3 (95%CI:0.6-2.8, p=0.5); KPS≤70, HR=3.2 (95%CI:1.6-.6.4, p<0.001); Lines of therapy ≥ 2, HR=2.3 (95%CI=0.8-5.7, p=0.08), male gender, HR=0.7 (95%CI:0.3-1.4, p=0.3).

      Conclusion
      Patients with stage IV PI3K-aberrant SQCLCs have poorer survival compared to other patients with SQCLCs while patients with FGFR1 amplified SQCLCs have a trend towards better survival. Brain metastases in SQCLC are rare, and occurred exclusively in patients with PI3K-aberrant tumors. These data suggest that PI3K pathway activation confers a distinct biology, and that targeting this in SQCLC patients with brain metastases may be an effective therapeutic strategy. Whole exome and RNA-sequencing data from 8 resected SQCLC brain metastases (4 paired with lung primaries) will be presented.

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    MO26 - Anatomical Pathology II (ID 129)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Pathology
    • Presentations: 1
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      MO26.04 - Reclassification of Resected Non-Small Cell Lung Carcinomas Originally Diagnosed as Squamous Cell Carcinoma, after Reevaluation Using Immunohistochemical Analysis (p40, p63, TTF-1, and Napsin A): Memorial Sloan-Kettering Cancer Center Experience (ID 2905)

      10:30 - 12:00  |  Author(s): N. Rekhtman

      • Abstract
      • Presentation
      • Slides

      Background
      Currently, non-small cell lung carcinomas (NSCLCs) are mainly classified by histologic analysis and mucin staining: (1) squamous cell carcinoma (SCC) shows keratinization and intercellular bridges; (2) adenocarcinoma shows lepidic, acinar, papillary, micropapillary, or solid pattern, with mucin production; and (3) large cell carcinoma lacks these findings. However, recent studies have shown promising improvements in the classification of NSCLC with immunostain-based markers, including p40 and thyroid transcription factor–1 (TTF-1). In this study, we investigate the use of immunohistochemical analysis in reclassifying NSCLCs originally diagnosed as SCCs.

      Methods
      All available tumor slides from patients with therapy-naive, surgically resected solitary NSCLCs originally diagnosed as SCC (1999-2009) were reviewed. Tissue microarrays were constructed with 3 cores (n=480), and immunostaining for p40, p63, TTF-1 (clone 8G7G3/1), TTF-1 (SPT24), napsin A, chromogranin A, synaptophysin, and CD56 was performed. Immunoreactivity was scored semiquantitatively by staining intensity (weak, moderate, or strong) and percentage of positive tumor cells (diffuse, ≥50%; focal, <50%). Tumors were first grouped by p40 and TTF-1 (8G7G3/1) status: (1) group A (favor SCC): p40 (+) and TTF-1 (8G7G3/1) (-); (2) group B (favor adenocarcinoma): p40 (- or +) and TTF-1 (8G7G3/1) (+); and (3) group C (favor large cell carcinoma): p40 (-) and TTF-1 (8G7G3/1) (-). Immunostain-based tumor classification was then confirmed with histologic findings and other markers.

      Results
      In group A (n=448), 1 tumor was reclassified as adenosquamous carcinoma by histologic findings and focal immunoreactivity for p40, p63, and TTF-1 (SPT24). In group B (n=15), 2 tumors were reclassified as large cell neuroendocrine carcinoma (LCNEC) by neuroendocrine morphologic findings and differentiation (1 as pure LCNEC and the other as combined LCNEC with SCC). In group C (n=17), 6 tumors were confirmed as large cell carcinoma because they lacked adenocarcinoma morphology and TTF-1 [SPT24] expression (2 of these showed focal p63 reactivity without keratinization); 4 were reclassified as large cell carcinoma (favor adenocarcinoma) because they were focally positive for TTF-1 (SPT24) but negative for TTF-1 (8G7G3/1) and napsin A; 2 were reclassified as adenocarcinoma because they were diffusely and strongly positive for TTF-1 (SPT24) but focally (<10%) positive for p63, without keratinization; 3 were reclassified as LCNEC by neuroendocrine morphologic findings and differentiation; and 2 were reclassified as small cell carcinoma by morphologic findings. All tumors finally diagnosed as SCC (n=447) using histologic findings and immunohistochemical analysis were positive for p40 and p63. Among them, 27 tumors were positive for TTF-1 (SPT24) (19 focally and 8 diffusely) but negative for TTF-1 (8G7G3/1), with all showing clear squamous morphologic pattern, thus verifying the greater specificity of the TTF-1 8G7G3/1 clone in SCC.

      Conclusion
      After immunohistochemical reevaluation of 480 NSCLCs originally diagnosed as SCC by classical morphologic analysis, 33 (7%) were reclassified as other histologic types. Immunohistochemical analysis may provide additional valuable information to achieve an accurate diagnosis, particularly in poorly differentiated NSCLCs and in tumors for which the diagnosis of nonkeratinizing SCC is considered.

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    O17 - Anatomical Pathology I (ID 128)

    • Event: WCLC 2013
    • Type: Oral Abstract Session
    • Track: Pathology
    • Presentations: 1
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      O17.05 - Accuracy and Interobserver Agreement in Identifying Histologic Subtypes in Stage I Lung Adenocarcinomas ≤3 cm Using Frozen Section (ID 2590)

      10:30 - 12:00  |  Author(s): N. Rekhtman

      • Abstract
      • Presentation
      • Slides

      Background
      The new IASLC/ATS/ERS classification of lung adenocarcinoma (ADC) histologic subtypes is now recommended for prognostic stratification. The ability to determine histologic subtype accurately by frozen section (FS) may help surgeons to choose limited resection versus anatomic resection in the management of lung ADC. The aim of this study is to investigate the accuracy and interobserver agreement of FS for predicting histologic subtype.

      Methods
      FS and permanent section slides from 361 surgically resected stage I lung ADCs ≤3 cm were reviewed for predominant histologic subtype and presence or absence of lepidic, acinar, papillary, micropapillary, and solid patterns. To determine interobserver agreement, 50 cases were additionally reviewed by 3 pathologists. To test the accuracy of FS in determining degree of invasion in cases with predominantly lepidic growth pattern, 5 pathologists reviewed FS slides from 35 patients and attempted to discriminate between adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic predominant adenocarcinoma (LPA).

      Results

      Parameter Accuracy, % (95% CI) Sensitivity, % (95% CI) Specificity, % (95% CI) κ
      Predominant histologic subtype
      Overall 68 (63–73) Not applicable Not applicable 0.565
      Lepidic 90 (86–92) 75 (64–84) 93 (90–96) 0.681
      Acinar 76 (71-80) 70 (61–77) 79 (73–84) 0.481
      Papillary 85 (81-88) 62 (50–72) 91 (87–94) 0.527
      Micropapillary 94 (91-96) 21 (9–40) 99 (97–100) 0.277
      Solid 91 (88-94) 79 (67–87) 94 (90–96) 0.700
      Presence or absence of each histologic pattern
      Lepidic 80 (76–84) 75 (69–80) 91 (84–96) 0.588
      Acinar 89 (85–92) 90 (86–93) 67 (35–90) 0.252
      Papillary 72 (67–77) 70 (64–75) 79 (69–87) 0.397
      Micropapillary 67 (62–72) 37 (30–45) 94 (89–97) 0.321
      Solid 84 (80–88) 69 (61–76) 96 (92–98) 0.670
      The accuracy of FS for predicting histologic subtype is shown in the Table. There was moderate agreement on the predominant histologic subtype between FS diagnosis and final diagnosis (κ=0.565). FS had high specificity for micropapillary and solid patterns (94% and 96%, respectively), but sensitivity was low (37% and 69%, respectively). The interobserver agreement was satisfactory (κ > 0.6, except for acinar pattern). All cases of AIS were correctly diagnosed using FS. For MIA, only 41.3% of FS diagnoses were correct, and 52% were overdiagnosed as LPA; for cases of LPA, 79% of FS diagnoses were correct.

      Conclusion
      FS can provide information on the presence of aggressive histologic patterns—micropapillary and solid—with high specificity but low sensitivity. FS is not suitable for determining the predominant pattern or degree of invasion. Although FS can be helpful in diagnosing AIS, it has poor accuracy in distinguishing MIA from LPA.

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    P1.06 - Poster Session 1 - Prognostic and Predictive Biomarkers (ID 161)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 1
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      P1.06-047 - Tumor expression of TTF1 is associated with a doubling of overall survival in patients with advanced lung adenocarcinomas (ID 2819)

      09:30 - 16:30  |  Author(s): N. Rekhtman

      • Abstract

      Background
      Expression of thyroid transcription factor 1 (TTF1) is commonly assessed to diagnose lung adenocarcinomas. TTF1 may also be an oncogenic driver. The prognostic impact of TTF1 expression in lung cancers has been evaluated. However, small sample sizes, population heterogeneity, and lack of control for genotype or targeted therapies have limited the interpretation and use of TTF1 as a prognostic variable.

      Methods
      We examined 638 consecutive patients with newly diagnosed (i.e. not recurrent disease) stage IV lung adenocarcinomas between 01/2009 and 09/2011. TTF1 was assessed by immunohistochemistry (8G7G3/1, DAKO, dilution 1:100); binary results were recorded (positive = any nuclear reactivity; negative = no reactivity). The association between TTF1 status and clinical variables (Chi-squared and t-tests), median survival (Kaplan-Meier methods, compared using logrank test), and outcomes with specific chemotherapies (Cox proportional hazard) and were assessed. Multivariate analysis of overall survival (Cox proportional hazard) was performed.

      Results
      TTF1 was assessed in 484 (76%) patients; 80% were TTF1+. TTF1 positivity associated with improved survival in all cohorts examined, although the EGFR cohort is limited by the small number of TTF1 negative tumors. TTF1+ was more common in EGFR (93%) than KRAS (76%) mutants (p<0.01). Figure 1 To reduce confounding from the effect of targeted therapy on survival, subsequent analyses excluded those with EGFR (n=129) mutations or ALK (n=12) rearrangements: In multivariate analysis, the HR for survival in TTF1+ patients was 0.42 (p<0.001), exceeding the prognostic impact of good performance status (KPS≥80, HR=0.54, p<0.001). There was no association between TTF1 and age (p=0.96), sex (p=0.41), smoking status (p=0.68), or performance status (p=0.07). TTF1 status did not predict improved outcomes with specific chemotherapies.

      Conclusion
      TTF1+ robustly and independently associates with improved survival in advanced lung adenocarcinomas. TTF1 exceeds the prognostic impact of clinical features (e.g. KPS) more commonly used to stratify patients. TTF1 should be assessed in all lung adenocarcinomas and should be used to stratify patients enrolled in clinical trials. Randomized trials are needed to conclusively assess if TTF1 predicts differential sensitivity to chemotherapies.

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    P2.18 - Poster Session 2 - Pathology (ID 176)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Pathology
    • Presentations: 1
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      P2.18-007 - Correlating Histologic and Molecular Features in the Lung Adenocarcinoma TCGA Project (ID 1698)

      09:30 - 16:30  |  Author(s): N. Rekhtman

      • Abstract

      Background
      Our understanding of the molecular landscape of lung adenocarcinoma (ADC) is evolving rapidly. Furthermore, the IASLC/ATS/ERS lung ADC classification was recently published. The histologic and molecular correlations have not yet been thoroughly explored in this rapidly changing field. We sought to investigate the molecular findings according to the IASLC/ATS/ERS classification. .

      Methods
      Aperio© scanned H&E stained slides were reviewed from 230 tumors according to the 2011 IASLC/ATS/ERS lung adenocarcinoma classification criteria. Molecular profiling was performed on 230 resected, untreated lung adenocarcinomas, using mRNA, miRNA and DNA sequencing integrated with copy number, methylation and proteomic analyses. Histologic molecular correlations focused on mRNA and DNA sequencing and TTF-1 proteomic findings.

      Results
      We found 12 lepidic predominant ADC (5%), 21 papillary predominant (9%), 77 acinar predominant (33%), 33 micropapillary predominant (14%), and 58 solid predominant (25%) as well as, 9 invasive mucinous (4%), and 20 unclassifiable ADCs (9%). EGFR mutation and KRAS mutations were found in 8% and 17% of lepidic ADC, respectively. Nine of 12 lepidic ADC (75%) were of the terminal respiratory unit (TRU) gene expression subtype (GES) and 3 (25%)were in the 19p-depleted transcriptional GES, but none were found in the solid-enriched GES (Figure; p=0.007). Most of the papillary ADC were of the TRU (10/21, 47.6%) and 19p-depleted transcriptional (9/21, 42.9%) GES (p=0.026). 46% (41/89) of acinar ADC tumors were in the TRU-GES compared to the solid enriched (18/78, 23.1%) and 19p-depleted transcriptional (18/63, 28.6%) GES (p=0.005). When the oncogene positive group was defined including KRAS, EGFR, ALK, RET, ROS1, BRAF, ERBB2, HRAS and NRAS, there was a higher percentage of solid ADC in the oncogene negative (30/93, 32.3%) compared to the oncogene positive group (28/137, 20.4%, p=0.046). The highest percentage of solid ADC was found in the solid-enriched GES (47/78, 47.4%) compared to the 19p-depleted transcriptional (17/63, 27%) and TRU GES (4/89, 4.5%) (p<0.001). Invasive mucinous ADC correlated with KRAS (but no EGFR) mutations (67%) compared to other ADC (28%, p=0.02) and also lacked elevation of TTF-1 (p=0.007). GES was associated with histologic grade: high grade with solid-enriched GES and intermediate/low grade with TRU GES (p<0.001). Figure 1

      Conclusion
      Our data reveal multiple correlations between molecular (mutation and GES) and histologic (subtyping and grade) features. This reveals insights into the biology of these tumors in particular genetic characteristics of the high grade tumors which may lead to better understanding of why these are more aggressive tumors.

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    P3.02 - Poster Session 3 - Novel Cancer Genes and Pathways (ID 149)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 1
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      P3.02-019 - FGFR1 amplification is associated with improved survival in patients with early-stage squamous cell carcinomas of the lung (SQCLC) (ID 2987)

      09:30 - 16:30  |  Author(s): N. Rekhtman

      • Abstract

      Background
      The spectrum and frequency of oncogenes in squamous cell lung cancers (SQCLCs) is actively being defined. Amplification of fibroblast growth factor receptor 1 (FGFR1) is the most common targetable oncogenic driver in SQCLCs, occurring in ~20%. Clinical trials of FGFR1 inhibitors for advanced SQCLCs are ongoing. The frequency, clinicopathologic features, and prognosis of FGFR1 amplification in early-stage SQCLCs have been reported but with discrepant results.

      Methods
      A cohort of histopathologically-defined and clinically-annotated resected SQCLCs was tested for FGFR1 amplification by FISH (Zytovision Dual Color Probe). Amplification was defined by FGFR1 copy number ≥2.2x CEP8 control copy number and was assessed by two evaluators (MW, LW) who were blinded to clinical results. Disease-free survival (DFS) defined as date of surgical resection until disease recurrent, relapse, or death, which ever occured first. DFS was estimated using Kaplan-Meier method. The association between FGFR1 status and clinical features (unpaired T-test, Fisher’s exact, Chi-square tests) and DFS (log-rank test for unadjusted analysis; Cox proportional hazards regression for multivariate analysis) were assessed.

      Results
      63 resected SQCLCs were evaluated. FGFR1 amplification was detected in 16 (24%). 56% were stage I, 24% were stage II, and 20% were stage IIIA. There was no association between FGFR1 amplification and age (p=0.86), sex (p=0.80), smoking status (p=0.37), or stage of disease (p=0.16). Median DFS was significantly longer in FGFR1-amplified cases compared to non-amplified cases: not reached vs 2.3 yrs (95% CI 1.1-3.4 yrs), p=0.02, with a corresponding unadjusted hazard ratio of 0.41 (95%CI: 0.19-0.88). Adjusted for sex and stage, multivariate analysis found FGFR1 amplification significantly associated with improved DFS (HR 0.31, 95%CI 0.1-0.89, p=0.03). Figure 1

      Conclusion
      FGFR1 amplification is associated with improved prognosis in this cohort of resected SQCLCs. The distinctive natural history substantiates FGFR1amplified SQCLCs as a unique, oncogene-defined subgroup. There was no association between FGFR1 status and sex, age, smoking status, or stage. FGFR1 amplification is common in SQCLCs.