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Ignacio I. Wistuba
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MA 01 - SCLC: Research Perspectives (ID 650)
- Event: WCLC 2017
- Type: Mini Oral
- Track: SCLC/Neuroendocrine Tumors
- Presentations: 1
- Moderators:John V Heymach, Eun Kyung Cho
- Coordinates: 10/16/2017, 11:00 - 12:30, Room 503
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MA 01.03 - The Potential of ctDNA Sequencing in Disease Monitoring and Depicting Genomic Evolution of Small-Cell Lung Cancer Under Therapy (ID 9682)
11:00 - 12:30 | Author(s): Ignacio I. Wistuba
- Abstract
- Presentation
Background:
Although small cell lung cancer (SCLC) is sensitive to initial therapy, almost all patients relapse and survival remains poor. Outgrowth of treatment-resistant subclones could be responsible for recurrence. However, genomic evolution of SCLC after treatment hasn’t been well investigated, partially due to the challenge of obtaining longitudinal samples. CT is the standard modality for response assessment and disease monitoring. But it doesn’t always accurately assess the disease status. SCLC is characterized by early hemagenous spread, which makes circulating tumor DNA (ctDNA) analysis a promising modality for genomic profiling and disease monitoring of SCLC.
Method:
Targeted-capture deep sequencing (mean target coverage 538x-1866x) of 545 cancer genes was performed to 44 ctDNA samples collected before therapy as baseline and at different timepoints during treatment from 23 SCLC patients. Pretreatment tumor biopsies from 8 patients were also sequenced (mean target coverage 348x-1281x) of the same gene panel. DNA from peripheral blood mononuclear cells was served as the germline control.
Result:
Mutations were identified in all 44 ctDNA samples with a median of 16 mutations per sample (average mutation burden of 6.6/Mb). TP53 and RB1 were the most frequently mutated genes, detected in 91% (21/23) and 65% (15/23) patients, respectively. 74 mutations were identified from the 8 tumor biopsies, among which, 69 (93.2%) were detected in matched ctDNA. We inferred subclonal architecture of each ctDNA sample based on cancer cell fraction derived using PyClone. A median of 10 (ranging 2-26) subclones was inferred from each ctDNA sample and only 17% (2% to 60.%) of mutations were clonal mutations suggesting substantial genomic heterogeneity. Single gene mutations were not associated with survival. However, mean variant allele frequency of clonal mutations (clonal-VAF) at baseline was associated with progression-free survival (PFS) and overall survival (OS) independent of stage, age, or platinum sensitivity. The median PFS of patients with higher versus lower than median clonal-VAF was 5.2 months (95% CI, 4.6 to 5.8 months) versus 10.0 months (95% CI, 9.3 to 10.7 months), p=0.002. The median OS was 8.1 months (95% CI, 5.5 to 10.7 months) versus 24.9 months (95% CI, 0.0 to 51.2 months) in patients with higher versus lower than median clonal-VAF, respectively, p=0.004. Analysis of serial ctDNA before and during treatment showed that clonal-VAF closely tracked closely with treatment responses.
Conclusion:
ctDNA sequencing is a promising modality for genomic profiling and disease monitoring for SCLC patients. Clonal VAF may be a better ctDNA metric than single gene mutations.
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MA 05 - Immuno-Oncology: Novel Biomarker Candidates (ID 658)
- Event: WCLC 2017
- Type: Mini Oral
- Track: Immunology and Immunotherapy
- Presentations: 1
- Moderators:Yoichi Nakanishi, P. Mitchell
- Coordinates: 10/16/2017, 15:45 - 17:30, Room 303 + 304
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MA 05.02 - STK11/LKB1 Loss of Function Genomic Alterations Predict Primary Resistance to PD-1/PD-L1 Axis Blockade in KRAS-Mutant NSCLC (ID 10367)
15:45 - 17:30 | Author(s): Ignacio I. Wistuba
- Abstract
- Presentation
Background:
The genomic landscape of primary resistance to PD-1 blockade in lung adenocarcinoma (LUAD) is largely unknown. We previously reported that co-mutations in STK11/LKB1 (KL) or TP53 (KP) define subgroups of KRAS-mutant LUAD with distinct therapeutic vulnerabilities and immune profiles. Here, we present updated data on the clinical efficacy of PD-1/PD-L1 inhibitors in co-mutation defined KRAS mutant and wild-type LUAD patients and examine the relationship between genetic alterations in individual genes, tumor cell PD-L1 expression and tumor mutational burden (TMB) using cohorts form the SU2C/ACS Lung Cancer Dream Team and Foundation Medicine (FM).
Method:
The cohorts included 924 LUAD with NGS (FM cohort) and 188 patients with KRAS non-squamous NSCLC (SU2C cohort) who received at least one cycle of PD-1/PD-L1 inhibitor therapy and had available molecular profiling. Tumor cell PD-L1 expression was tested using E1L3N IHC (SU2C) and the VENTANA PD-L1 (SP142) assay (FM). TMB was defined as previously described and was classified as high (TMB-H), intermediate (TMB-I) or low (TMB-L).
Result:
188 immunotherapy-treated (83.5% nivolumab, 11.7% pembrolizumab, 4.8% anti-PD1/PD-L1 plus anti-CTLA-4) pts with KRAS-mutant NSCLC were included in the efficacy analysis. The ORR differed significantly between the KL (8.8%), KP (35.9%) and K-only sub-groups (27.3%) (P=0.0011, Fisher’s exact test). KL LUAC exhibited significantly shorter PFS (mPFS 1.8m vs 2.7m, HR=0.53, 95% CI 0.34-0.84, P<0.001, log-rank test) and OS (mOS 6.8m vs 15.6m, HR 0.53, 95% CI 0.34 to 0.84, P=0.0072, log rank test) compared to KRAS-mutant NSCLC with wild-type STK11. Loss-of function (LOF) genetic alterations in STK11 were the only significantly enriched event in PD-L1 negative, TMB-I/H compared to PD-L1 high positive (TPS≥50%), TMB-I/H tumors in the overall FMI cohort (Bonferroni adjusted P=2.38x10[-4], Fisher’s exact test) and among KRAS-mutant tumors (adjusted P=0.05, Fisher’s exact test) . Notably, PD-1 blockade demonstrated activity among 10 PD-L1-negative KP tumors, with 3 PRs and 4SDs recorded. In syngeneic isogenic murine models PD-1 blockade significantly inhibited the growth of Kras mutant tumors with wild-type LKB1 (K), but not those with LKB1 loss (KL), providing evidence that LKB1 loss can play a causative role in promoting PD-1 inhibitor resistance.
Conclusion:
Loss of function genomic alterations in STK11 represent a dominant driver of de novo resistance to PD-1/PD-L1 blockade in KRAS-mutant NSCLC. In addition to tumor PD-L1 status and tumor mutational burden precision immunotherapy approaches should take into consideration the STK11 status of individual tumors.
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MS 15 - Molecular Testing (ID 537)
- Event: WCLC 2017
- Type: Mini Symposium
- Track: Biology/Pathology
- Presentations: 1
- Moderators:J.S. Lee, Iver Petersen
- Coordinates: 10/17/2017, 15:45 - 17:30, Room 301 + 302
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MS 15.02 - Molecular Testing Using NGS (ID 7712)
15:45 - 17:30 | Presenting Author(s): Ignacio I. Wistuba
- Abstract
- Presentation
Abstract:
Lung cancer has shown a decrease in incidence and mortality in recent decades; however, it remains one of the cancers with the highest incidence and ranks first in cancer-related deaths in the United States. Despite advances in early detection and standard treatment, most patients are diagnosed at an advanced stage and have a poor prognosis, with an overall 5-year survival rate of 10% to 15%. Lung cancer is a heterogeneous disease comprising several subtypes with pathologic and clinical relevance. The recognition of histologic subtypes of non-small cell lung carcinoma (NSCLC), namely adenocarcinoma, squamous cell carcinoma, and large cell lung carcinoma as the most frequent subtypes, has become important as a determinant of therapy in this disease. In addition, in recent years, the identification of molecular abnormalities in a large proportion of patients with lung cancer has allowed the emergence of personalized targeted therapies and has opened new horizons and created new expectations for these patients. The use of predictive biomarkers to identify tumors that could respond to targeted therapies has meant a change in the paradigm of lung cancer diagnosis. This paradigm change affects all stakeholders in the fight against lung cancer including pathologists. Currently, several multiplex genotyping platforms for the detection of oncogene mutations, gene amplifications and deletions, and rearrangement are moving to the clinical setting. Genome-wide molecular investigations using next-generation sequencing (NGS) technologies have been evaluated in the research setting, with promising results. Further investigations in NSCLC are required for a better understanding of the implications of intratumor heterogeneity and the roles of tumor suppressor genes and epigenetic events with no known driver mutations. NGS in the clinical setting will provide comprehensive information cheaper and faster by using small amounts of tissue. Recently, NGS genotyping platforms utilization has extended to liquid biopsy (cell free DNA). Pathologists should be able to precisely handle tissue adequacy in terms of quantity and quality and maintaining tumor cells for detection of molecular alterations. The clinical successes of targeted therapy and immunotherapy approaches to lung cancer have posed additional challenges to the scientific community and pathologists to develop predictive biomarkers of response to these therapies and have highlighted the need for proper procurement and processing of tissue specimens from patients with lung cancer.
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OA 13 - Immuno-Biology (ID 677)
- Event: WCLC 2017
- Type: Oral
- Track: Immunology and Immunotherapy
- Presentations: 2
- Moderators:Hiroyuki Suzuki, Scott N. Gettinger
- Coordinates: 10/18/2017, 11:00 - 12:30, Room 301 + 302
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OA 13.01 - CD38-Mediated Immunometabolic Suppression as a Mechanism of Resistance to PD-1/PD-L1 Axis Blockade (ID 10157)
11:00 - 12:30 | Author(s): Ignacio I. Wistuba
- Abstract
- Presentation
Background:
Although immune checkpoint inhibitors of the PD-1/PD-L1 axis provide significant clinical benefit for patients with lung cancer, effective use of these agents is encumbered by a high rate of primary or acquired resistance. Strategies for optimal therapeutic application of immunotherapy require a thorough understanding of resistance mechanisms. To date, there have been only a few studies reporting potential mechanisms of resistance to PD-1/PD-L1 blockade.
Method:
In multiple immunocompetent syngeneic and spontaneous animal models of K-ras/p53 mutant lung cancer, we explored the resistance mechanisms to PD-1/PD-L1 blockade using both pharmacologic and genetic approaches (therapeutic antibody treatment and CRISPR/Cas9-mediated editing). The molecular and immune profiles of the tumor microenvironment were evaluated. Additionally, to determine the applicability to patients with lung cancer, we analyzed 259 tumor specimens with IHC staining and mRNA expression, and further confirmed the analyses in publically-available TCGA datasets.
Result:
In multiple models of antibody blockade and genetic knockout of PD-L1, we identified the up-regulation of CD38 on tumor cells as a marker of treatment resistance. Furthermore, by manipulating CD38 on a panel of lung cancer cell lines we demonstrated in vitro and in vivo that CD38 expression inhibits CD8[+] T cell proliferation, anti-tumor cytokine secretion, and tumor cell killing capability. The T cell suppressive effect is dependent upon the ectoenzyme activity of CD38 that regulates the extracellular levels of adenosine. To test whether CD38 blockade might be therapeutically efficacious to prevent anti-PD-L1/PD-1 resistance, we applied combination therapy with anti-CD38 and anti-PD-L1 and demonstrated dramatic therapeutic benefit on primary tumor growth and metastasis. Additionally, in a set of 259 resected lung cancer specimens, ~15% exhibited positive staining for CD38 on tumor cells, and the expression correlated with cytolytic T cell score and an immune/inflammatory signature across multiple large datasets.
Conclusion:
CD38 was found to be a novel mechanism for tumor escape from immune checkpoint PD-1/PD-L1 inhibitor therapy. Targeting this resistance pathway may broaden the benefit of PD-L1/PD-1 axis blockade for lung cancer treatment.
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OA 13.05 - Immune, Molecular and T Cell Repertoire Landscape of 235 Resected Non-Small Cell Lung Cancers and Paired Normal Lung Tissues (ID 8766)
11:00 - 12:30 | Author(s): Ignacio I. Wistuba
- Abstract
- Presentation
Background:
Non-small cell lung cancer (NSCLC) is characterized by a high mutational load. Accordingly, it is also among the tumor types responding to immune checkpoint blockade, likely through harnessing of the anti-tumor T cell response. However, the lung is continuously exposed to the outside environment, which may result in a continuous state of inflammation against outside pathogens unrelated to the tumor microenvironment. Therefore, further investigation into the T cell repertoire and T cell phenotypes across normal lung and tumor is warranted.
Method:
We performed T cell receptor (TCR) sequencing on peripheral blood mononuclear cells (PBMC), normal lung, and tumor from 225 NSCLC patients, among which, 96 patients were also subjected to whole exome sequencing (WES) of PBMC, tumor and normal lung tissues. We further performed Cytometry by Time-of-Flight (CyTOF) on 10 NSCLC tumors and paired normal lung tissues to phenotype immune and T cell subsets.
Result:
Comparison of the T cell repertoire showed 9% (from 4% to 15%) of T cell clones were shared between normal lung and paired tumor. Furthermore, among the top 100 clones identified in the tumor, on average 57 (from 0 to 95) were shared with paired normal lung tissue. Interestingly, T cell clonality was higher in the normal lung in 89% of patients suggesting potential differences in the immune response and immunogenicity. A substantial number of somatic mutations were also identified not only in NSCLC tumors (average 566; from 147 to 2819), but also in morphologically normal lung tissues (average 156; from 50 to 2481). CyTOF demonstrated striking differences in the immune infiltrate between normal lung and tumor, namely a lower frequency of PD-1+CD28+ T cells (both CD4+ and CD8+) in the normal lung (2.7% versus 3.0% in tumor). In addition, a unique GITR+ T cell subset (0.96%) was entirely restricted to the normal lung. Conversely, increases in regulatory T cell frequency (CD4+FoxP3+) were observed in the tumor (10.4% vs 1.7% in normal lung), further highlighting the differences in T cell phenotype and response across normal lung and tumor.
Conclusion:
These results suggest that a substantial proportion of infiltrating T cells in NSCLC tumors may be residential T cells associated with response to environmental factors. However, normal lung and NSCLC tumors carry T cells of distinct phenotypes including increases in immunosuppressive T cells within the tumor which may further highlight the differences in the anti-tumor immune response.
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P2.02 - Biology/Pathology (ID 616)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Biology/Pathology
- Presentations: 3
- Moderators:
- Coordinates: 10/17/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P2.02-013 - Investigation of Genomic and TCR Repertoire Evolution of AAH, AIS, MIA to Invasive Lung Adenocarcinoma by Multiregion Exome and TCR Sequencing (ID 9192)
09:30 - 16:00 | Author(s): Ignacio I. Wistuba
- Abstract
Background:
Carcinogenesis may result from accumulation of molecular aberrations (molecular evolution) and escaping from host immune surveillance (immunoediting). It has been postulated that atypical adenomatous hyperplasia (AAH) represents preneoplastic lesion that may progress to adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA) and further to frankly invasive adenocarcinoma (ADC). However, due to lack of appropriate study materials, the molecular and immune landscape of AAH, AIS or MIA have not been well studied and the definition and management of these lesions remain controversial.
Method:
With the intent to delineate the pivotal molecular and immune events during early carcinogenesis of lung adenocarcinoma, we have collected 119 resected pre- and early neoplastic lung lesions including AAH (N=24), AIS (N=27), MIA (N=54) and ADC (N=14) from 53 patients including 41 patients presenting with multifocal lesions and 25 patients carrying more than one type of pathology. Two to five spatially separated regions from each lesion were subjected to whole exome sequencing and T cell receptor sequencing.
Result:
Mutation burden (average SNVs) was found to progressively increase from 1.32/Mb in AAH to 2.55/MB in AIS, 5.42/MB in MIA and 15.38/MB in ADC. Genomic heterogeneity has also become more complex with neoplastic progression with mean Shannon index of 1.53 in AAH, 1.78 in AIS, 1.56 in MIA and 1.79 in ADC. An increase in C>A transversions coincident with a decrease in A>G transitions and progressively increasing APOBEC enrichment scores (4.13 in AAH, 5.63 in AIS, 6.02 in MIA and 6.59 in ADC) were observed with neoplastic disease progression. Furthermore, phylogenetic analysis revealed varying evolutional processes in AAH, AIS, MIA and ADC with canonical cancer gene mutations in KRAS, ATM, TP53 and EGFR etc. as key drivers in a subset of patients. TCR sequencing demonstrated a progressive decrease in T cell density (average percent T cells among all nuclear cells: 12% in AAH, 8% in AIS, 7% in MIA and 4% in ADC) and a progressive decrease in productive TCR clonality (average productive TCR clonality: 0.0434 in AAH, 0.0427 in AIS, 0.0399 in MIA and 0.0395 in ADC) suggesting suppressive T cell repertoire in more advanced diseases.
Conclusion:
Our results provide molecular evidence supporting the model of early lung carcinogenesis from AAH, to AIS, MIA and ADC and demonstrated that with disease progression, genomic landscape of lung neoplastic lesions has become progressively more complex along with progressive immunosuppressive TCR repertoire.
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P2.02-046 - Assessment of PDL1 and Immunoprofiling Using Multiplex Quantitative Immunofluorescence in Lung Cancer: Clinical Implications (ID 10245)
09:30 - 16:00 | Author(s): Ignacio I. Wistuba
- Abstract
Background:
Understanding of the “profile” of PD-L1 expression and its interplay with immune cells will provide important insights into lung cancer pathogenesis, and immunotherapeutic strategies targeting this important immune checkpoint protein. The aim was to investigate the correlation between multiplex immunofluorescence (mIF) expression of PD-L1, density and nature of tumor infiltrating immune cells in non-small cell lung carcinomas (NSCLC), and correlate those profiles with clinical and pathological variables including patient outcome.
Method:
We studied 194 stage II/III patients that underwent pulmonary resection, including 98 adenocarcinoma (ADC), 59 squamous cell carcinoma (SqCC), 15 large cells carcinomas (LCC) and 22 neuroendocrine carcinomas (NEC), primary tumors. Formalin-fixed and paraffin embedded (FFPE) tissue microarrays were constructed with five 1.5 mm cores representative of histologic patterns found in each tumor. mIF was performed using the Opal 7-color fIHC Kit™, scanning in the Vectra™ multispectral microscope and analyzed using the inForm™ software (Perkin Elmer, Waltham, MA). The markers studied were grouped in two 6-antibody panels: Panel 1, AE1/AE3 pancytokeratins, PD-L1 (clone E1L3N), PD-1, CD3, CD8 and CD68; and Panel 2, AE1/AE3, Granzyme B, CD45RO and CD57, FOXP3, and CD20. General linear model was used to evaluate the interaction among primary vs metastatic tumors, histologic type and TAICs and Cox's proportional hazard model for overall survival (OS).
Result:
Fifty-eight % out of 164 tumors were positive for PDL-1+ expression (5% cut-off) in malignant cells (EA1/EA3+). Significant higher levels of PD-L1+ expression were detected in NEC compared with other histologies (ADC, SqCC and LCC) (P=0.006). In the same way, we observed higher densities of cytotoxic T lymphocytes (CD3+CD8+) in NEC when compared with the lowest expression in SqCC (P=0.02). Large cell carcinomas presented high levels of memory/regulatory T cells (CD3+FOXP3+CD45RO+) compared with other histologic types but the difference didn´t achieve statistical significance. No difference was found for CD3+PD-L1+, CD68+PD-L1+, natural killer T lymphocytes (CD3+CD57+) and B lymphocytes (CD20+) among the histologic types. Difference between primary and metastatic tumors was found only for naive/memory T lymphocytes (CD3+ CD45RO+) (P=0.04). High CD3+FOXP3+CD45RO+ and CD3+PDL1+ expression were independent favorable prognostic factor for DFS and OS adjusted by smoking, primary vs metastatic, and histologic type [HR 2.68, 95% (CI 1.37–5.24), P=0.004; HR 2.11 (CI 1.07-4.18, P=0.03].
Conclusion:
High abundance of CD3+PD-L1+ cells and memory/regulatory T cells CD3+FOXP3+CD54RO are favorable prognostic factors for resected NSCLC, highlighting the importance of comprehensive assessment of both tumor and immune cells. Supported by CNPq P246042/2012-5 e CNPq 301411/2016-6; FAPESP 2013/10113-7.
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P2.02-061 - Two Novel Protein-Based Prognostic Signatures Improve Risk Stratification of Early Lung ADC and SCC Patients (ID 9518)
09:30 - 16:00 | Author(s): Ignacio I. Wistuba
- Abstract
Background:
The development of robust, feasible and clinically useful molecular classifiers for early stage NSCLC patients to assess the risk of developing post-resection recurrence is an unmet medical need. Here we identified and validated the clinical utility of two different histotype-specific protein-based prognostic signatures to stratify the five-year risk of lung cancer recurrence or death in patients with either early lung adenocarcinoma (ADC) or early squamous cell carcinoma (SCC). The signatures are based on the immunohistochemical detection of three and five proteins, for ADC and SCC respectively
Method:
A total number of 562 lung cancer patients were included in this study (n=350 for ADC and n=212 for SSC). A training cohort was used to assess the value of the prognostic signatures based on immunohistochemical (IHC) detection (n=239 ADC and n=117 SSC). The prognostic signatures were developed by Cox regression analysis and were comprised of three and five proteins, respectively for ADC and SCC. Overfitting and optimism were quantified and calibrated by internal validation by applying shrinkage and bootstraping combination. The performance of the models was externally validated in a second cohort of 111 and 95 patients with stage I-II lung ADC and SCC, respectively.
Result:
The prognostic indexes (PIs) generated by the models were significant predictors of five-year outcome for disease-free survival: [P<0.001, HR=2.88 (95% CI, 1.77-4.69)] for ADC and [P<0.001; HR=2.97 (95% CI, 1.84-4.79)] for SCC; and overall survival: [P<0.001, HR=4.04 (95% CI, 2.30-7.10)] for ADC and [P=0.006; HR=1.86 (95% CI, 1.20-2.88)] for SCC, independently of other clinicopathological parameters. The prognostic ability of both PIs was externally validated in the second cohort of early stage lung cancer patients (P<0.05). The molecular classifiers added significant information to pathological stage. Combined models including both PIs and the pathological stage (CPIs) improved the risk stratification in both cases (P<0.001). Moreover, using the CPI value we were able to select the group of stage I-IIA patients who could obtain a benefit from platinum-based adjuvant chemotherapy treatment (P<0.05) in both histological subtypes.
Conclusion:
This study identifies and validates two protein-based prognostic signatures that accurately identify early lung cancer patients with high risk of recurrence or death. More importantly, the proposed models may be valuable tools to identify the subset of stage I-IIA patients for whom adjuvant chemotherapy could be beneficial.
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P3.03 - Chemotherapy/Targeted Therapy (ID 719)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Chemotherapy/Targeted Therapy
- Presentations: 2
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.03-007 - LCMC2: Expanded Profiling of Lung Adenocarcinomas Identifies ROS1 and RET Rearrangements and TP53 Mutations as a Negative Prognostic Factor (ID 8338)
09:30 - 16:00 | Author(s): Ignacio I. Wistuba
- Abstract
Background:
The Lung Cancers Mutation Consortium (LCMC) is a multi-institutional effort where 16 sites identify oncogenic drivers and pool data to assess the impact of targeted therapies in patients with lung adenocarcinomas. We now report the results of the second patient cohort (LCMC2) with an expanded multiplex molecular panel to include RET and ROS1 and tumor suppressors.
Method:
904 patients with centrally confirmed stage IV lung adenocarcinomas who were candidates for therapy had at least one of 14 oncogenic drivers assessed in a CLIA-compliant laboratory using genotyping, FISH, massively parallel sequencing (NGS), and immunohistochemistry (IHC) analyses.
Result:
Among 423 patients tested for all 14 targets, we found a driver in 65%. Mutated KRAS was found in 31%, sensitizing EGFR in 14%, MET amplification in 5%, ALK rearrangements in 4%, BRAF V600E in 3%, and HER2 in 3%. Rearrangements in RET and ROS1 were each found in 2% (CI 1 to 3%). Using IHC, PTEN loss was found in 8% (CI 6 to 11%) and MET expression in 58% (CI 55 to 61%). Use of targeted therapies in patients with EGFR, HER2, or BRAF mutations, ALK, ROS1, or RET rearrangements, and MET amplification was associated with a gain in overall survival of 1.5 years relative to those with the same drivers not receiving targeted therapy and a gain of 1 year relative to those without an actionable driver. Current and former cigarette smokers derived a survival benefit from targeted therapies similar to never smokers (p=0.975). Among 154 patients who had all drivers assessed and NGS testing in addition, any TP53 mutation was associated with poorer survival among those with EGFR, ALK, or ROS1 (p=0.014). STK11 was detected in 11%, all in patients with KRAS mutations.
Conclusion:
Using an expanded testing panel, LCMC2 demonstrates the survival benefit of matching targeted treatments to oncogenic drivers in patients with lung adenocarcinomas, identifies additional prognostic factors, and supports the performance of multiplex molecular testing on specimens from all individuals with lung adenocarcinomas irrespective of clinical characteristics. We detected either MET amplifications or HER2 mutations in 7%, together more than the 4% with ALK. A targeted drug is available in the United States for 35% of patients with lung adenocarcinomas. The routine use of massively parallel sequencing (NGS) detects both targetable drivers and tumor suppressor genes that have significance for therapy selection and prognosis. Supported by Free to Breathe
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P3.03-027 - LKB1 Loss Is Associated with Resistance to Anti-Angiogenic Therapy in Non-Small Cell Lung Cancer Mouse Models (ID 10259)
09:30 - 16:00 | Author(s): Ignacio I. Wistuba
- Abstract
Background:
LKB1 is a protein kinase that is mutated and down-regulated in 20-30% of non-small cell lung cancer (NSCLC). LKB1 mutations co-occur with KRAS alterations in 7%-10% of NSCLC, resulting in an aggressive phenotype with short survival. Because LKB1 activates AMPK, the master sensor of cellular energy, many of the best known functions of LKB1 are attributed to its ability to control metabolic alterations in the cells. However LKB1 also plays an important role in regulating angiogenesis, likely as a strategy to overcome energetic depletion of tumor microenvironment. Bevacizumab, the human anti-VEGF antibody, improves the PFS and OS of NSCLC patients combined with chemotherapy, but often the benefit is transient and therapeutic resistance occurs. Our laboratory has previously identified alterations in cell metabolism and in vasculature of LKB1-deficient tumors when compared to LKB1 wild type in NSCLC.
Method:
LKB1 KO murine NSCLC cell lines were generated using CRISPR/Cas9 system in a KRAS[G12D] mutant background (LKR10 & LKR13). Syngeneic NSCLC models were established via s.c. injection of LKB1 intact and KO murine cells in immunocompetent mice. After tumors reached 150 mm[3] mice were randomly assigned to treatment groups consisting of vehicle, mouse anti-VEGF and nintedanib. Tumor volumes were measured and compared using student’s t test and samples were collected for vasculature analysis. Survival curves will be calculated using log rank test. Hypoxia experiments were preformed and apoptosis was measured using annexin V and 7ADD staining.
Result:
Treatment with anti-VEGF or nintedanib significantly inhibited tumor progression in LKB1 wt KRAS[G12D] mutant mouse model (p<0.001) but did not show any therapeutic effect in the LKB1 KO KRAS[G12D] group. Furthermore in the LKB1 wt group, the median survival of anti-VEGF and nintedanib treated mice was 111 days and 84 days respectively and 37 days in the vehicle group. No improvement in survival was detected in the LKB1 KO group after treatment with anti-VEGF. In vitro studies showed that LKB1 loss is associated with a decrease in oxygen consumption and enhanced glycolysis. Furthermore LKB1 KO NSCLC cells showed a decrease in apoptosis under hypoxic and low nutrient conditions compared to LKR13 LKB1 wt cells.
Conclusion:
NSCLC LKB1-deficient tumors showed resistance to anti-angiogenic therapy and this effect is driven by the regulation of metabolic adaptations that allow cells to survive under hypoxic and low nutrient conditions.
