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Background Next generation sequencing (NGS) of tumor of patients with advanced non–small cell lung cancer (NSCLC) is now a standard of care that informs the clinician on the best therapeutic approach for their patients. The purpose of our study was to investigate the overall impact of NGS testing on survival as well as potential racial differences in utilization, therapeutic decision, and genomic alterations. Method Using a large institutional database, 928 patients with stage IV NSCLC were identified. NGS testing using Foundation One platform was used. Clinical and genomic characteristics were compared by race. We used a propensity-modeling technique to compare groups that were sequenced or not in terms of overall survival. Time to event data was analyzed using Kaplan-Meier method and Cox model. Results A total of 295 patients underwent NGS. Patients undergoing NGS testing had significantly longer survival of 25.3 months versus those who did not undergo sequencing with a median survival of 14.6 months (P = .002) irrespective if they received targeted therapy or not. There was no difference in terms of NGS utilization based on race (P = .32). African American individuals had significantly higher rates of ALK rearrangements and mutations in PBRM1, SETD2, TSC2, and FBXW7. Conclusion Our study demonstrates that within a large single institution there is no racial difference in NGS utilization and that NGS testing directly impacts survival. We identify a number of differences in genomic findings between African American and white individuals.

Background Although many studies have determined that PD-L1 expression by immunohistochemistry can be somewhat predictive of a response to checkpoint inhibitor the impact of specific genomic changes and smoking history in the context of PD-L1 expression is limited. This single-center study examined clinical and genomic factors beyond STK11 and EGFR in patients with advanced non-small cell lung cancer (NSCLC) to determine which patients benefit from therapy with immune checkpoint inhibitors (ICIs). Methods Clinical and genomic features of patients with NSCLC treated with immunotherapy were compiled into a database. Genomic information collected included gene mutations via next generation sequencing, tumor mutation burden (TMB), and PD-L1 tumor proportional scores. Results A total of 131 patients with advanced NSCLC treated with ICIs were examined. Race was not associated with response. A positive response to immunotherapy was associated with smoke year increase (P=0.042). KRAS mutation and MYC amplification were associated with a positive response to immunotherapy while EGFR, RB1, and NF1 mutations were associated with a lack of response. KRAS mutation (P=0.007) and high TMB (P=0.070) were positively associated with smoking history. EGFR mutation was negatively associated with smoking history (P=0.002) . In multivariate analysis controlling for age and smoking history, MYC amplification continued to be the only predictive genomic marker with a trend toward response to therapy (P=0.092) beyond the smoking history. Conclusions Among the clinical and genomic factors examined in this study, smoking status is the most predictive of response to ICIs. Only MYC amplification continued to predict a trend toward response to immunotherapy when controlling for smoking history. Other genomic predictors such as EGFR and KRAS simply reflect their association with smoking. Detailed smoking history and MYC amplification alone can predict response to ICI.

Mixed-lineage leukemia protein 2 (MLL2 or KMT2D) is a histone methyltransferase whose mutation has been associated with a poor prognosis in cancer. We compared the characteristics and significance of KMT2D alterations in non-small-cell lung cancer (NSCLC) with those in small cell lung cancer (SCLC).Tumors from 194 NSCLC patients with locally advanced or advanced disease and 64 SCLC patients underwent targeted-exome sequencing. The association of KMT2D mutation with overall survival (OS) and progression-free survival (PFS) was measured using Kaplan-Meier methods and further evaluated using multivariable Cox proportional hazards regression model adjusting for known clinical prognostic features.The KMT2D mutation rate was 17.5% (34 of 194) in NSCLC. Patients with mutant KMT2D had significantly lower median OS (9.97 vs. 30.2 months; P .0001) and median PFS (8.46 vs. 24.1 months; P = .0004) compared with patients with wild-type KMT2D. The KMT2D mutation was significantly more common in females (P = .017). Using a multivariate Cox regression model, KMT2D mutation was one of the most significant prognostic factors in NSCLC: hazard ratio (HR) for OS, 2.79 (95% confidence interval [CI], 1.8-4.33; P .0001) and HR for PFS, 1.99 (95% CI, 1.32-3.01; P = .001). In contrast, the KMT2D mutation rate in SCLC was 32.8% (21 of 64) and showed no sex bias (P = .874). No significant change was found in survival in association with the KMT2D mutation in SCLC (OS, P = .952; PFS, P = .744).The KMT2D mutation was associated with reduced survival in NSCLC but not in SCLC.

// Karen McColl 1 , Gary Wildey 1 , Nneha Sakre 1 , Mary Beth Lipka 1 , Mohadese Behtaj 2 , Adam Kresak 3 , Yanwen Chen 4 , Michael Yang 2 , Vamsidhar Velcheti 5 , Pingfu Fu 4 and Afshin Dowlati 6 1 Division of Hematology and Oncology, Case Western Reserve University, Cleveland, OH, USA 2 Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA 3 Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA 4 Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA 5 Division of Hematology and Oncology, Cleveland Clinic Foundation, Cleveland, OH, USA 6 Division of Hematology and Oncology, Case Western Reserve University, University Hospitals Seidman Cancer Center, Cleveland, OH, USA Correspondence to: Afshin Dowlati, email: // Keywords : INSM1, YAP1, small cell, RB1, CDK4/6 Received : July 28, 2017 Accepted : August 03, 2017 Published : August 28, 2017 Abstract The majority of small cell lung cancer (SCLC) patients demonstrate initial chemo-sensitivity, whereas a distinct subgroup of SCLC patients, termed chemo-refractory, do not respond to treatment. There is little understanding of how to distinguish these patients prior to disease treatment. Here we used gene expression profiling to stratify SCLC into subgroups and characterized a molecular phenotype that may identify, in part, chemo-refractive SCLC patients. Two subgroups of SCLC were identified in both cell lines and tumors by the reciprocal expression of two genes; INSM1 , a neuroendocrine transcription factor, and YAP1 , a key mediator of the Hippo pathway. The great majority of tumors expressed INSM1, which was prognostic for increased progression-free survival and associated with chemo-sensitivity in cell lines. YAP1 is expressed in a minority of SCLC tumors and was shown in cell lines to be downstream of the retinoblastoma protein (RB1) and associated with decreased drug sensitivity. RB1 expression in SCLC cell lines sensitizes them to CDK4/6 inhibitors. Wild-type RB1 mutation status, used as a surrogate marker of YAP1 expression, was prognostic for decreased patient survival and increased chemo-refractory tumor response. Thus, the reciprocal expression of INSM1 and YAP1 appears to stratify SCLC into distinct subgroups and may be useful, along with RB1 mutation status, to identify chemo-refractory SCLC patients.

Background Genomic studies in small-cell lung cancer (SCLC) lag far behind those carried out in nonsmall-cell lung cancer (NSCLC). To date, most SCLC studies have evaluated patients with surgically resectable disease. Here we sought to evaluate the genomic mutation spectrum of ‘every-day’ SCLC patient tumors with extensive stage disease (ES-SCLC) and to correlate mutations with the main clinical outcomes of response to chemotherapy, progression-free (PFS) and overall (OS) survival. Patients and methods A total of 50 SCLC patient tumors were examined in this study; targeted exome sequencing was obtained on 42 patients and whole-exome sequencing on 8 patients. Mutated genes were correlated with clinical outcomes using Kaplan–Meier methods (PFS, OS) and logistic regression (chemo-response). RB1 protein expression was detected by either western blotting of cultured cell lysates or immunohistochemistry of tumor specimens. Results In all, 39 patients had ES-SCLC; 15 patients had either primary refractory/resistant disease and 21 patients had sensitive disease. The two most frequently mutated genes were TP53 (86%) and RB1 (58%); other frequently mutated genes (>10% patients) were involved in epigenetic regulation as well as the mTOR pathway. We identified a number of low-frequency, targetable mutations, including RICTOR, FGFR1, KIT, PTCH1 and RET. Using multivariate analysis, RB1 was the only significant factor (P = 0.038) in predicting response to first-line chemotherapy, with an odds ratio of 5.58 comparing mutant RB1 with wild-type. Patients with mutant RB1 had both better OS (11.7 versus 9.1 months P = 0.04) and PFS (11.2 versus 8.6 months, P = 0.06) compared with patients with wild-type RB1. Interestingly, ∼25% of SCLC cell lines and tumor specimens expressed RB1 protein, possibly representing the subgroup with wild-type RB1. Conclusions We found that SCLC tumors harboring no mutation in RB1 had a poor response to chemotherapy.

The retinoblastoma gene (RB1) encodes the retinoblastoma (RB) pocket protein that plays an important role in cell cycle progression. Here we determine the frequency and prognostic significance of RB1 mutation in non small cell lung cancer (NSCLC), restricting inclusion to Stage III and IV patients with linked genomic and clinical data. The primary outcome was median overall survival (OS). We identified RB1 mutation in 8.2% of NSCLC patients. The median OS for wild‐type (wt) RB1 was 28.3 months vs 8.3 months for mutant RB1 (Hazard Ratio = 2.59, P = 0.002). Of special interest, RB1 mutation also correlated with lack of response to immunotherapy. Our study focused on RB1 mutation in locally advanced and advanced non small cell lung cancer to better facilitate comparisons with small cell lung cancer (SCLC). In our SCLC cohort, RB1 mutation was identified in 75% of patients and wt RB1 was associated with significantly shorter OS (P = 0.002). The different outcomes of RB1 mutation observed among lung cancer subtypes suggest a more complicated mechanism than simple regulation of cell cycle or response to chemotherapy.

8526Background: The clinical outcome of Non-Small Cell Cancer (NSCLC) has been advanced with molecular targeted therapy. To our knowledge, there is no data addressing targeted therapy outcomes base...

e20017 Background: Genomic studies in small cell lung cancer (SCLC) are hampered by the small amounts of biopsy tissue typically available. The emergence of ‘liquid biopsy’ to identify tumor DNA mutations in plasma (circulating tumor DNA or ctDNA) has the potential to overcome this restriction and also facilitates multiple sampling during disease treatment. Here we use ctDNA to compare mutation profiles in SCLC and non-small cell lung cancer (NSCLC)patients and to identify changes that occur post-relapse in SCLC. Methods: Targeted exome sequencing of 73 genes in plasma from 13 SCLC and 17 NSCLC patients was obtained along with matched patient targeted exome sequencingof 315 genes for 6 SCLC and 8 NSCLC tumor biopsies. Only the 70 genes analyzed by both assays were studied. Results: 3 SCLC and 8 NSCLC ctDNA specimens were collected pre-treatment, with the remainder post-relapse. In SCLC, 46 total gene mutations were detected in ctDNA with a mean allelic fraction (mAF) of 16.0%. TP53 (mAF 30.8%, N= 15) and ARID1A (mAF 16.0%, N= 6) were the most frequently mutated SCLC genes. In NSCLC, 53 gene mutations were detected with a mAF of 2.5%. TP53 (mAF 5.9%, N= 13), EGFR (mAF 2.3%, N= 10) and KRAS (mAF 4.4%, N= 5) were frequently mutated NSCLC genes. 44 and 10 gene amplifications were detected in SCLC and NSCLC ctDNA, respectively. 5 SCLC patients with tumor DNA profiles obtained pre-treatment had matching ctDNA profiles obtained post-relapse. TP53 mutation status agreed in 4 of the matched specimens. 6 new gene mutations occurred post-relapse in ctDNA, notably a TSC1 mutation (AF 8.4%) in one patient. 7 tumor gene mutations were lost post-relapse, notably ARID1A and NTRK1 mutations were lost in two patients each. Remarkably, 23 new gene amplifications were detected post-relapse in ctDNA, including PIK3CA ( N= 5) and CCNE1 ( N= 5), whereas only 1 was detected in pre-treatment tumors. Conclusions: SCLC exhibits much greater ctDNA mAF values than NSCLC, although their overall mutation profiles agree with published tumor DNA mutation profiles. Interestingly, the predominant change observed in SCLC ctDNA profiles in relapsed specimens is increased gene amplification.

11598 Background: Myeloid/lymphoid or mixed-lineage leukemia protein 2 (MLL2) is an epigenetic regulator expressed in many tissues. Although MLL2 mutations are associated with poor prognosis in different types of cancer, the clinical impact of this gene in lung cancer remains unclear. Here, we evaluated the clinical and genomic characteristics of MLL2 alteration in non-small cell lung cancer (NSCLC) and compared it to small cell lung cancer (SCLC) Methods: Between 2014 and 2016 tumor samples of 194 Stage III and IV NSCLC patients and 50 SCLC patients underwent targeted-exome sequencing. The association of MLL2 mutation with survival outcomes was measured using Kaplan–Meier methods (PFS, OS). Cox’s proportional hazards regression model was performed for multivariate survival analyses with known clinical prognostic features. All tests were two-sided and p-values = 0.05 were considered statistically significant. Results: The MLL2 mutation rate was 17.5% (N=34) in NSCLC. Patients with mutant MLL2 had significantly lower overall survival (OS) (9.97 vs. 30.2 months, p < 0.0001) and progression-free survival (PFS) (8.46 vs. 24.1 month, p = 0.0007) compared to those with wild type MLL2. The median overall survival in the entire NSCLC cohort was 23.3 months (95% CI: 16.5 – 34.4). Interestingly, MLL2 mutation was significantly more common in females (p = 0.017). There was no significant association of MLL2 mutation status with age, smoking history, race or histology . Using a multivariate Cox regression model with adjustments based on tumor stage, smoking histology and chemotherapy, MLL2 mutation remained the most remarkable prognostic factor in NSCLC: OS Hazard Ratio 2.79, p = 0.0001 and PFS Hazard Ratio 1.99, p < 0.001. By comparison, the MLL2 mutation rate in SCLC was 24% (N=12) and showed no gender bias (p=0.874). There was no significant decrease in survival associated with MLL2 mutation in SCLC (OS p = 0.966, PFS p = 0.641). Conclusions: This study demonstrates that MLL2 mutation specifically impacts survival outcome only in NSCLC but not SCLC.

9060 Background: Genomic profiling of tumor DNA has revealed the diversity in NSCLC. The retinoblastoma gene ( RB1) encodes for RB pocket protein that plays an important role in cell cycle progression by interacting with various transcriptional factors. Here we determine the frequency and prognostic significance of RB1mutation in NSCLC and compare it to that in small cell lung cancer (SCLC). Methods: This IRB-approved retrospective review on NSCLC patients included Stage III and IV patients with genomic and clinical data. Primary outcome was median overall survival (OS) and secondary outcome was progression-free survival (PFS). OS and PFS were calculated by the Kaplan-Meier method and compared between mutant and wild-type (wt) RB1using the Log-Rank test. The effect of RB1mutation status on OS and PFS was further evaluated using the multivariable Cox model, controlling the effects of age, sex, stage, smoking history and chemotherapy. All tests are two-sided and p-values ≤ 0.05 were considered statistically significant. Results: We identified RB1 mutation in 8.2% of NSCLC patients (16 of 195 patients). With a median follow-up of 15.1 months, the median OS for wt RB1was 28.3 months and for mutant RB1 was 8.3 months (HR = 2.59, p-value = 0.002). The median PFS for wt RB1 was 21.8 months vs 6.4 months for mutant RB1 (HR = 2.85, p-value = 0.0002). RB1 mutation was associated with worse OS ( p= 0.017, HR = 2.17) and PFS ( p= 0.005, HR = 2.37) in multivariate analyses after adjusting for traditional risk factors like, age, sex, stage, smoking history and chemotherapy. Interestingly, a previously described benign deletion (A16-A18) in RB1 protein was identified in 5 of the 16 RB1 mutant patients and was associated with far worse outcomes compared to other RB1 mutations. In contrast to NSCLC, RB1 mutation was identified in 75% of 64 SCLC patients. Furthermore, wt RB1 was associated with significantly shorter OS ( p= 0.002), PFS ( p= 0.004) and chemotherapy refractoriness ( p= 0.033) in SCLC. Conclusions: RB1 mutation is present in a minority of patients with advanced NSCLC and is associated with poor prognosis. In contrast, RB1 mutation is present in the majority of SCLC patients and is associated with a favorable prognosis.

7575 Background: Genomic studies in small cell lung cancer (SCLC) lag far behind those performed in non-small cell lung cancer (NSCLC). Unlike NSCLC, where specific mutations such as ALK and EGFR a...