Background: Insomnia is the most common sleep complaint; no doubt it is on the rise among medical students throughout their overwhelming long journey. Smoking is defined as burning plant material, mostly tobacco, which is known to contain nicotine. Previous studies found that nicotine had a negative impact on sleep architecture. Accordingly, Smokers are more likely to report clinical insomnia than nonsmokers. The current study aimed to determine the impact of smoking on insomnia among medical students at Jordan University of Science and Technology (JUST). Objective: Both Insomnia and smoking tobacco are currently two major issues in our society. This study aims to see if there’s any possible association between the two so we be could be able to overcome them. Method: We conducted an observational cross-sectional study, medical students (n=140) filled an online questionnaire including demographic data, BMI, the 7-item insomnia severity index scale questions accredited by the American Psychological Association that was used to assess Insomnia and categorized as none, subthreshold, moderate and severe, and 6 self-designed questions about smoking (status, types, behavior). Statistical analysis was performed by means of descriptive tables and Chi-square test using IBM SPSS software. Results: There were 140 responses (F=52.1%, M=47.9%). The prevalence of insomnia among participants regardless of their smoking status showed that (44.3%) had subthreshold insomnia whereas (21.4%) had moderate-to-severe insomnia. About (20.7%) of all participants are current smokers; (24.1%) of them had moderate to severe clinical insomnia while (75.9%) have no clinically significant and subthreshold insomnia. The chi-square test results had shown no statistically significant association between prevalence of insomnia and smoking status (p=0.432). Conclusion: This study suggests there is no association between smoking and insomnia prevalence among Jordanian medical students. Considering the small sample size, prospective cohort studies of larger sample sizes are needed to explore details of this association. Keywords: Insomnia, Smoking, Sleep Disturbance

Pancreatic neuroendocrine tumors (PanNETs) represent a clinically challenging disease because these tumors vary in clinical presentation, natural history, and prognosis. Novel prognostic biomarkers are needed to improve patient stratification and treatment options. Several putative prognostic and/or predictive biomarkers (eg, alternative lengthening of telomeres, alpha-thalassemia/mental retardation, X-linked (ATRX)/Death Domain Associated Protein (DAXX) loss) have been independently validated. Additionally, recent transcriptomic and epigenetic studies focusing on endocrine differentiation have identified PanNET subtypes that display similarities to either α-cells or β-cells and differ in clinical outcomes. Thus, future prospective studies that incorporate genomic and epigenetic biomarkers are warranted and have translational potential for individualized therapeutic and surveillance strategies.

Abstract Peptide receptor radionuclide therapy (PRRT) is a treatment option for somatostatin receptor–positive, unresectable or metastatic neuroendocrine tumors (NETs). Despite high disease control rates seen with PRRT, a subset of the NET population seems to have a short progression-free interval. We hypothesize that patients with NETs with rapid progression post-PRRT may have mixed low- and high-grade cell populations, and PRRT treats the lower-grade component, allowing the more aggressive high-grade component to progress. We report 7 patients with biopsy-proven NET who received PRRT with 177Lu-DOTATATE at the Stanford Cancer Center who had evidence of progressive disease (PD) on or within 6 months of therapy. All patients had primary pancreatic, metastatic, well-differentiated NET on diagnosis and were heavily pretreated before receiving PRRT. Two patients had PD while on PRRT; 5 had PD within 6 months of completing PRRT. The median time from the last cycle to PD was 3.2 months (range, 1.1–4.6 months). The median progression-free survival was 7.7 months (95% confidence interval, 5.7–9.8 months). Three patients had a repeat biopsy post-PRRT, 2 of which demonstrated higher disease grade compared with their initial pathology. Further evaluation in larger patient cohorts is warranted to elucidate predictive factors of PRRT response/nonresponse to enable better patient selection.

Abstract Background: Pancreatic neoplasms consist of exocrine, endocrine and benign tumors. Exocrine pancreatic cancer is the fourth leading cause of cancer-related death in the US. Racial disparities in incidence, diagnosis, treatment, and outcomes have been evaluated in different types of tumors, but the data on pancreatic neoplasms are lacking. Our aim is to evaluate the racial disparities in clinical characteristics and survival of patients with pancreatic neoplasms. Methods: Using the National Cancer Database (NCDB), we identified 340,780 patients diagnosed with a pancreatic neoplasm between 2004 and 2015. Simple descriptive statistics were created for all covariates. Chi-square analysis was used to examine the distribution of demographic and clinicopathologic variables among different races. Survival analysis was done on patients with either death dates or follow-up dates, totaling 305,576 patients. Kaplan Meier survival analysis was used for unadjusted results, and Cox proportional hazards model was used for multivariable analysis. Races were grouped into White, Black, Hispanic, and others. The objective of the study is to assess racial disparities in clinical presentation, and to evaluate whether this influences the outcomes in patients with pancreatic neoplasms. Results: The median age at diagnosis was 69 (range 18-90) years and 50.6% were males. Carcinoma was the most common histology (81.3%), followed by other histology (9.6%), benign (5.4%) and neuroendocrine (3.7%) tumors. The percent of White, Black, Hispanic, and other race was 74.5, 11.3, 5.0, and 9.1%. Whites presented at more advanced ages compared to Blacks, Hispanics, and others (78.3, 68.6, 69.3, 76.3% were ≥60 years at diagnosis; p<0.0001). Blacks and Hispanics presented more frequently with advanced stage (III and IV) of the disease compared to Whites (54.7, 52.8, 50.9%; p<0.0001). Uninsured patients had a higher risk of death compared to those with insurance, HR=1.11 [95% CI 1.09-1.14]. Patients with lower annual income had a higher hazard of death (one example: <$38,000 vs >$63,000 HR=1.20 [95% CI 1.19-1.22]). Unadjusted analysis showed Blacks had a marginally higher hazard of death than Whites, HR=1.02 [95% CI 1.01-1.03]. However, after adjustment for age, sex, histology, grade, comorbidity score, income, education, and year of diagnosis, Blacks and Hispanics had a slightly better overall survival than Whites, HR=0.96 [95% CI 0.94-0.97] and 0.85 [95% CI 0.84-0.87]. Among patients with treatment information, time to first treatment was significantly longer among Blacks and Hispanics compared to Whites (4.4 and 3.2 days longer on average, p<0.0001). Conclusion: Our study provides evidence that various disparities exist across different races in pancreatic neoplasms. However, they did not lead to inferior outcomes in minorities. Our findings should be examined in other cohorts where more data about treatment are available. Citation Format: Hussein Assi, Michael Machiorlatti, Sara Vesely, Vipul Pareek, Hassan Hatoum, Sarbajit Mukherjee. Racial disparities in clinical characteristics and outcomes of patients with pancreatic neoplasms: An eleven-year analysis of the National Cancer Database (NCDB) [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C086.

Assi, Hussein A. MD, MS; Shikdar, Sufana MD; Alhyari, Laith MD; Aljumaily, Raid MD Author Information

PURPOSE:Urinary tract cancer can be pure urothelial carcinoma, pure nonurothelial carcinoma or variant urothelial carcinoma (defined here as mixed urothelial carcinoma). Little is known regarding outcomes for patients with variant urothelial carcinoma receiving immune checkpoint inhibitors. We hypothesized that variant urothelial carcinoma does not compromise immune checkpoint inhibitor efficacy in patients with advanced urothelial carcinoma.MATERIALS AND METHODS:We performed a retrospective cohort study across 18 institutions. Demographic, clinicopathological, treatment and outcomes data were collected for patients with advanced urothelial carcinoma who received immune checkpoint inhibitors. Patients were divided into pure vs variant urothelial carcinoma subgroups, with variant urothelial carcinoma further divided by type of variant (ie squamous, neuroendocrine etc). We compared overall response rate using univariate and multivariate logistic regression and progression-free survival and overall survival using Kaplan-Meier and univariate and multivariate Cox proportional hazards.RESULTS:Overall 519 patients were identified, with 395, 406 and 403 included in overall response rate, overall survival and progression-free survival analyses, respectively. Overall response rate to immune checkpoint inhibitors between patients with pure vs variant urothelial carcinoma was comparable (28% vs 29%, p=0.90) without significant differences for individual subtypes vs pure urothelial carcinoma. Median overall survival for patients with pure urothelial carcinoma was 11.0 months vs 10.1 months for variant urothelial carcinoma (p=0.60), but only 4.6 months for patients with neuroendocrine features (9 patients, HR 2.75, 95% CI 1.40-5.40 vs pure urothelial carcinoma, p=0.003). Median progression-free survival was 4.1 months for pure vs 5.2 months for variant urothelial carcinoma (p=0.43) and 3.7 months for neuroendocrine features (HR 1.87, 95% CI 0.92-3.79 vs pure urothelial carcinoma, p=0.09).CONCLUSIONS:Overall response rate to immune checkpoint inhibitors was comparable across histological types. However, overall survival was worse for patients with tumors containing neuroendocrine features. Variant urothelial carcinoma should not exclude patients from receiving immune checkpoint inhibitors.

Background: Immune-related adverse events are associated with efficacy of immune checkpoint inhibitors (ICIs). We hypothesize that immune-mediated thrombocytopenia could be a biomarker for response to ICIs. Materials & methods: This retrospective study included 215 patients with metastatic malignancies treated with ICIs. Patients were stratified by nadir platelet count. Outcomes of interest were progression-free survival and overall survival. Results: On multivariate analysis, grade 1 thrombocytopenia was positively associated with overall survival compared with patients who did not develop thrombocytopenia (hazard ratio [HR]= 0.28 [95% CI: 0.13–0.60]; p = 0.001), while grade 2–4 thrombocytopenia was not (HR= 0.36 [95% CI: 0.13–1.04]; p = 0.060). There was no association between degree of thrombocytopenia and progression-free survival. Conclusion: Follow-up studies are warranted to substantiate the predictive significance of thrombocytopenia in patients receiving ICIs.

BACKGROUND:Fibrolamellar carcinoma (FLC) is a very rare liver tumor. We aimed to retrospectively analyze the clinicopathological factors and treatment modalities affecting overall survival (OS) in FLC. The objective of the study was to identify predictors of survival in FLC.PATIENTS AND METHODS:Using the National Cancer Database, we identified 496 patients diagnosed with FLC between 2004 and 2015. Clinicopathological, treatment, and survival data were collected.RESULTS:Hepatic resection was performed on 254 (51.2%) patients, liver-directed therapy on 13 (2.6%) patients, and liver transplantation on 15 (3.0%) patients. Median OS by stage were 142.1, 87.2, 32.3, and 14.1 months for stages 1, 2, 3, and 4, respectively. Metastatectomy was not associated with superior median OS (23.4 vs. 10.5 months, p=0.163). Age ≤40, low Charlson-Deyo comorbidity score, early stage and hepatic resection were independently associated with longer OS.CONCLUSION:Our study reports current trends in FLC management, and identifies independent predictors of OS.

The present study was conducted to detect the contaminated microbial pathogens of fresh red meat indifferent places of the al-butcher shops, where 100 samples and swabs were collected from different placesand tools from meat shops in different areas in Nasiriyah for the period from September 2018 to March2019. The highest isolation rate for Escherichia coli isolates was different according to the type of sampletaken (31.53% meat samples, 21.42% the ground, 21.33% cutting boards, 19.1% cutting tools). 15 isolateswere selected for the sensitivity test for eight antibiotics, to detect resistance genes, sul1 and tet (B) Theisolates were highly resistant to Ampicillin, Vancomicin, Amoxicillin at a rate of 100%, they were verysensitive to antimicrobial antiperspirants such as Trimethoprim, Norfloxacin, Chloramphenicol at a rateof 100%, The sensitivity of Tetracycline and Gentamycin was 86.7% and 80% respectively. The resultsof the electrical relay were shown after DNA extraction using Kit and amplified the genes using a PCR.Specialized gene primers were used for each gene, the presence of the resistant gene sul1 in the isolatesof E. coli was 80%, and the tet (B) was 87.3%. Some isolates were record as new strains in the NCBIgene bank database.

TPS464 Background: Neoadjuvant chemoradiation (CRT) followed by surgery is a standard approach for localized EGAC. Despite multimodality treatment, 5-year overall survival (OS) is less than 50%, with pathologic complete response (pCR) rates of 20%. Achievement of pCR is associated with an improved OS. We propose to use a novel combination of FTD/TPI and oxaliplatin as IC. We hypothesize that IC before CRT will increase the pCR rate in localized EGAC. Methods: This is an open-label, multicenter phase II trial. Patients (pts) with potentially resectable loco-regional EGAC are eligible. Pts. should have adequate organ function, ECOG performance status of 0 –1, age < 76 years, and endoscopic ultrasound-determined node-positive disease with any T-stage, or T3-T4a with any N stage. Pts. with T4b or M1 disease will be excluded. Pts. will receive three cycles of IC with FTD/TPI and oxaliplatin. Based on the maximum tolerated dose (MTD) observed in a phase I trial, FTD/TPI will be administered 35 mg/m² BID, days 1–5 every 14 days, with a fixed dose of oxaliplatin 85 mg/m² (day 1). Pts will then undergo concurrent CRT (standard radiation dose of 5040 cGY will be utilized) with weekly Carboplatin (AUC 2) and Paclitaxel (50 mg/m2) for 6 weeks followed by surgery. Our primary objective is to evaluate the pCR rate. The secondary objectives include evaluation of 2-year disease-free survival (DFS), 2-year OS, and assessment of toxicities of the IC. As a correlative endpoint, circulating tumor DNA level will be correlated with disease recurrence and metabolic response on PET CT. Assuming a historic pCR rate of 20% with standard CRT, 41 pts (enrollment of up to 45 pts accounting for non-evaluable pts) are needed to show a 15% increase in pCR with IC with 80% power at one-sided significance level of α = 0.1. In stage 1, n1= 22 evaluable pts will be enrolled. If there is 5 or more pCRs, an additional n2= 19 pts will be enrolled in stage 2. If 12 or more pCRs are observed in the total n = 41 evaluable pts, then the proposed treatment regimen will be considered promising for further study. We anticipate accrual over a 2-year period from 3 sites. Clinical trial information: NCT04097028.

BackgroundImmune checkpoint inhibitors (ICIs) represent an appealing treatment for patients with advanced urothelial cancer (aUC) and a poor performance status (PS). However, the benefit of ICIs for patients with a poor PS remains unknown. It was hypothesized that a poor Eastern Cooperative Oncology Group (ECOG) PS (≥2 vs 0‐1) would correlate with shorter overall survival (OS) in patients receiving ICIs.MethodsIn this retrospective cohort study, clinicopathologic, treatment, and outcome data were collected for patients with aUC who were treated with ICIs at 18 institutions (2013‐2019). The overall response rate (ORR) and OS were compared for patients with an ECOG PS of 0 to 1 and patients with an ECOG PS ≥ 2 at ICI initiation. The association between a new ICI in the last 30 and 90 days of life (DOL) and death location was also tested.ResultsOf the 519 patients treated with ICIs, 395 and 384 were included in OS and ORR analyses, respectively, with 26% and 24% having a PS ≥ 2. OS was higher in those with a PS of 0 to 1 than those with a PS ≥ 2 who were treated in the first line (median, 15.2 vs 7.2 months; hazard ratio [HR], 0.62; P = .01) but not in subsequent lines (median, 9.8 vs 8.2 months; HR, 0.78; P = .27). ORRs were similar for patients with a PS of 0 to 1 and patients with a PS ≥ 2 in both lines. Of the 288 patients who died, 10% and 32% started ICIs in the last 30 and 90 DOL, respectively. ICI initiation in the last 30 DOL was associated with increased odds of death in a hospital (odds ratio, 2.89; P = .04).ConclusionsDespite comparable ORRs, ICIs may not overcome the negative prognostic role of a poor PS, particularly in the first‐line setting, and the initiation of ICIs in the last 30 DOL was associated with hospital death location.

447 Background: While ICI prolong OS after platinum chemotherapy in aUC, outcomes vary based on clinical confounders. We aimed to develop a prognostic model in pts receiving ICI in a non-clinical trial setting. Methods: We used a hypothesis driven approach of clinician selected covariates to develop a new prognostic model. Data source was a retrospective cohort of pts treated with ICI at 19 institutions. Demographics, clinicopathologic data, treatment patterns, and OS were collected. Univariate (UVA) Cox regression was done on 24 variables hypothesized to be associated with OS. Variables were retained for multivariate analysis (MVA) if they had statistical relationship with OS (p<0.2) and were included in the final model if p<0.05 on MVA. Each retained covariate was assigned 1 point in the final prognostic model. Stratified median OS and c-statistic were calculated. Results: 415 pts with mean age 69, 26% female, 66% ever smokers, 69% pure UC, 15% upper tract UC, 54% with prior extirpative surgery, Bellmunt risk factors 17%, 51%, 28% and 4% for 0, 1, 2, 3, respectively were included. Non-White race, ECOG PS≥1, albumin<3.5g/dL (lower limit of normal), hemoglobin<10g/dL, absolute neutrophil count (ANC)>8x106/ul (upper limit of normal), and presence of bone or liver metastases (mets) were all associated with worse OS on UVA Cox regression; albumin<3.5 g/dL, ANC>8x106/uL, presence of bone or liver mets remained significant on MVA and were included in the prognostic model. Median (m)OS by new model and Bellmunt are shown in table. C-statistic of the new model was 0.67. Conclusions: Albumin<3.5 g/dL, ANC >8x106/ul, presence of bone or liver mets were negative prognostic factors in pts with aUC treated with ICI. This has comparable features to recently reported 5-factor model using clinical trial data, including LDH (unavailable in our cohort). External validation is being pursued. The proposed model may be used for prognostication, clinical trial design, eligibility and stratification. [Table: see text]

Neuroendocrine tumors of the lung are a diverse group of diseases with distinct pathological, molecular, and clinical characteristics. The most recent World Health Organization (WHO) classification identifies two types of high-grade neuroendocrine carcinomas of the lung: small cell lung carcinoma (SCLC), and the less common large cell neuroendocrine carcinoma of the lung (LCNEC). Systemic treatments for these aggressive tumors have largely remained unchanged for years. With the advancement in genomic sequencing and identification of novel targetable pathways over the last decade, a myriad of therapeutic options have emerged, addressing unmet needs for this patient population. In this review, we summarize the latest advances in the management of SCLC and LCNEC, and discuss promising endeavors in development.

495 Background: Urinary tract cancer can be pure urothelial carcinoma (PUC) or variant UC (VUC, defined here as pure non-UC or mixed UC + non-UC); VUC often has a worse prognosis. Little is known about outcomes for patients (pts) with VUC receiving ICI. We hypothesized that VUC does not compromise ICI efficacy in pts with aUC. Methods: We performed a retrospective cohort study across 18 institutions. Demographic, clinicopathologic, treatment and outcomes data was collected for pts with aUC who received ICI. Pts were stratified to PUC vs VUC; VUC was further divided by histologic subtype, i.e. squamous, neuroendocrine (NE), etc. We compared overall response rate (ORR) using logistic regression, progression free survival (PFS) and overall survival (OS) using Kaplan-Meier and Cox proportional hazards; p<0.05 was significant. Results: 519 consecutive pts were identified; 405, 414 and 411 included in ORR, OS and PFS analyses, respectively. Demographics included mean age 69, 27% female, 66% ever smokers, 15% upper tract disease, 54% with extirpative surgery. ORR to ICI between pts with PUC and VUC was comparable (both 28%, p=0.86) without significant differences for individual subtypes vs PUC. Median OS for pts with PUC was 11.0 vs 9.9 mo for VUC (p=0.45), but only 3.7 mo for those with NE features (HR=3.01 [95% CI 1.63-5.57] vs PUC, p<0.001). Median PFS was 4.1 vs 5.2 mo for PUC vs VUC (p=0.46) and 2.8 mo for NE (HR=1.85 [95% CI 0.94-3.61] vs PUC, p=0.07). Conclusions: ORR to ICI and OS were comparable across histologic types; however, OS was shorter for tumors with NE features. VUC should not exclude pts from receiving ICI in routine practice and clinical trials.[Table: see text]

413 Background: Fibrolamellar carcinoma (FLC) is a very rare liver tumor, comprising only 1% of all primary liver tumors in the United Sates. There is no standard of care for unresectable disease. Current practices are based on small retrospective studies and case series. We aim to analyze the clinicopathologic factors and treatment modalities affecting overall survival (OS) in FLC. Methods: Using the National Cancer Data Base (NCDB), we identified 496 patients diagnosed with FLC between 2004 and 2015. Simple descriptive statistics were created for all covariates. Survival data was available on 461 patients. Kaplan Meier Survival analysis was used for unadjusted results, and Cox proportional hazards model was used for multivariable analysis. The objective of the study is to identify predictors of survival in FLC. Results: The median age at diagnosis was 32 (range 18-90) years. Fifty-six percent were males. Stage distribution included 114 (31.2%), 43 (11.8%), 89 (24.3%) and 120 (32.8%) patients for stages I, II, III and IV, respectively. Median follow-up was 24 months. Surgery of the primary site was performed on 282 (56.9%) of patients, 146 (51.2%) of which had regional lymph node dissection. Seventy (47.9%) patients had pN+ disease. Among patients with available serum alpha fetoprotein (AFP) data, 146 (42.5%) had abnormal AFP levels (> 20 ng/mL). Median OS by stage were 78.5, 87.2, 18.6, and 10.6 months for stages I, II, III, and IV, respectively. Multivariate analysis showed that age (HR 1.01, p < 0.0001), pN+ (HR 2.31, p = 0.0003), and abnormal AFP (HR 1.69, p = 0.0003) were negative predictors of survival. Among metastatic patients, 57 (11.4%) had metastatectomy. Metastatectomy improved overall survival in stage IV FLC, HR 0.51 (95% CI 0.29-0.89). Conclusions: Independent predictors of decreased OS in patients with FLC include age, pN+ and abnormal AFP. Metastatectomy improved OS. FLC is a rare disease entity that warrants further investigations to better delineate optimal treatment approaches.

BACKGROUND:Pancreatic neuroendocrine tumors (panNETs) are a rare group of tumors that make up 2%-3% of pancreatic tumors. Recommended treatment for panNETs generally consists of resection for symptomatic or large asymptomatic tumors; however, optimal management for localized disease is still controversial, with conflicting recommendations in established guidelines. Our study aim is to compare surgical intervention versus active surveillance in nonmetastatic panNETs by size of primary tumor. MATERIALS AND METHODS:Using the National Cancer Database, we identified 2,004 patients diagnosed with localized well-differentiated, nonfunctional panNETs (NF-panNETs) between 2004 and 2015. Patients' clinicopathologic characteristics, treatment modalities, and overall survival (OS) were analyzed using frequency statistics, chi-square, and Kaplan-Meier curves. The objective of the study is to assess the outcome of surgical resection versus nonoperative management in patients with panNETs with different tumor sizes. RESULTS:Tumor sizes were divided into three categories: <1 cm, 1-2 cm, and >2 cm. The number of patients with tumor size <1 cm, 1-2 cm, and >2 cm was 220 (11%), 794 (39.6%), and 990 (49.4%), respectively. Overall, 1,781 underwent surgical resection, whereas 223 patients did not. Median follow-up was 25.9 months. After adjusting for covariates, surgical resection was associated with improved OS in patients with tumor size 1-2 cm (hazard ratio [HR] = 0.37) and >2c m (HR = 0.30) but not <1 cm (HR = 2.81). Independent prognostic factors were age at diagnosis, Charlson-Deyo comorbidity score, stage, tumor location, and surgical resection. Higher tumor grade was not associated with worse OS. CONCLUSION:Our findings suggest that active surveillance is potentially a safe approach for NF-panNETs <1 cm. Larger tumors likely need active intervention. Intermediate-grade tumors did not result in worse survival outcome compared with low-grade tumors. Future studies might consider prospective randomized clinical trials to validate our findings. IMPLICATIONS FOR PRACTICE:The present study seeks to address the discrepancy in treatment recommendations in the management of nonfunctional pancreatic neuroendocrine tumors (NF-panNETs) by evaluating whether surgical resection is associated with improved overall survival in different tumor size groups as well as elucidating independent prognostic factors in patients with NF-panNETs. Data from the National Cancer Database were reviewed. This study's findings suggest that active surveillance is potentially a safe approach for NF-panNETs <1 cm. Larger tumors likely need active intervention. Independent prognostic factors include age at diagnosis, Charlson-Deyo comorbidity score, stage, tumor location, and surgical resection. These findings will help guide medical and surgical oncologists when formulating treatment plans for patients with small NF-panNETs.

Background: Immunotherapy directed against the PD-1/PDL-1 (programmed cell death protein [ligand] 1) pathway has shown activity across a range of malignancies. Immune-related adverse events have been shown to be associated with the efficacy of PD-1/PDL-1 inhibitors in patients with melanoma and non-small cell lung cancer. Thrombocytopenia has been reported in up to 33% of patients receiving anti PD-1/PDL-1 therapy. Our hypothesis is that immune-mediated thrombocytopenia may be a biomarker for response to anti PD-1/PDL-1 therapy.