Citations

8549 Background: Bronchial carcinoid tumors are a rare group of neoplasms that usually have an indolent clinical behavior. Surgical resection is the main treatment modality for patients with early stage disease, however it is unclear if lobectomy with mediastinal lymph node dissection (L) is superior compared to partial lobectomy (PL). Methods: Utilizing the National Cancer Database from 2004-2012, 1551 patients diagnosed with T1N0 or T2N0 typical carcinoid tumors (CT), and 167 atypical carcinoid tumors (ACT), who underwent L or PL (segmental or wedge resection) as initial treatment strategy, and did not receive chemotherapy or radiation were identified. All patients had pathologically confirmed diagnosis, negative surgical margins, and complete follow up data. Overall survival (OS) was analyzed utilizing Kaplan-Meier curves, and log-rank tests were used for statistical comparisons. Cox proportional hazards were performed to control for age, sex, race, grade, year of diagnosis, Charlson/Deyo Score, insurance, income, and facility type. T-test was used to compare post-surgical hospital stay. Results: The entire cohort median age was 61 years (range 18-90), and male to female ratio was 0.43. 75% of patients with CT and 78% of ATC underwent L. The 90 day mortality following surgery was < 1 % in both surgical groups. Patients who underwent L had longer post-operative hospitalization stay (mean 5.3 vs. 4.3 days; p < 0.001). The 5 year survival for patients with CT was 95% in the L versus 93% in the PL group (p = 0.62), and for ACT 89% in the L versus 81% PL group (p = 0.28). In a multivariate analysis increasing age was the only prognostic factor, and was associated with inferior survival. The HR for death comparing PL to L was 1.09 (95% CI: 0.65-1.78; p = 0.71) for CT and 1.25 (95% CI: 0.45-3.23; p = 0.65) for ACT. Conclusions: Patients with localized node-negative CT and ACT have excellent 5 year survival. Performing a lobectomy with mediastinal node dissection may not provide additional benefit compared to partial lobectomy, but this may increase the length of hospital stay.

2533 Background: Many cancer clinical trials (CT) lack appropriate representation of specific patients populations, limiting the generalizability of the evidence obtained. Therefore, we determined the representation of ethnic minorities in oncology CT. Methods: Enrollment data from all therapeutic trials reported as completed in clinicaltrial.gov from 2003 to 2016 were analyzed. CT in rare cancers (< 1% incidence) or with recruitment outside of the US were excluded. Enrollment fraction (EF) was defined as the number of enrollees divided by the 2013 SEER database cancer prevalence. Chi-square test was used to estimate differences in categorical data. Results: Out of 1,012 CT, 310 (31%) reported ethnicity with a total of 55689 enrollees. Distribution by race and comparison with data from 1996-2002, US cancer prevalence and US census are described in the Table. Participation in CT varied significantly across ethnic groups, non-Hispanic Whites (NHW) were more likely to be enrolled in CT (EF of 1.2%) than African Americans (EF of 0.7%, p < 0.001) and Hispanics (EF of 0.4%, p<0.001). A decrease in African Americans (AA) and Hispanics (H) enrollment was observed when compared with historical data from 1996 to 2002. Hispanics were less represented in breast and prostate cancer CT contributing only to 3% and 1.5% of the study population; African Americans were less represented in lung (5.4%) and renal cell carcinoma (3%) trials. Asians were well represented and their recruitment doubled over the past 14 years (2% vs 5.3%). Conclusions: African Americans and Hispanics were less likely to be enrolled in CT. Comparing with historical data; we observed a decrease in minorities’ recruitment in the past 14 years. This change could be attributed to the increased complexity of CT and mandatory molecular testing as many minorities lack access to institutions with genetic testing capacity. Future trials should take extra measures to recruit participants that adequately represent the U.S. cancer population. [Table: see text]

8533 Background: BNET are a rare and frequently indolent group of neoplasms. Lobectomy is frequently done for patients with non-metastatic disease, and the role of adjuvant chemotherapy for patients with node positive disease (N+) is debated. Methods: Utilizing the National Cancer Database from 2004-2012 we identified 1682 patients with N+ non-metastatic BNET. All patients underwent primary resection, had pathologically confirmed diagnosis, complete follow up data, and were alive > 30 days following surgery. Overall survival (OS) was analyzed utilizing Kaplan-Meier curves, and log-rank tests were used to compare 2 groups of patients that differed based on receiving or not adjuvant chemotherapy. Subgroup analyses were performed based on histologic subtypes. Cox proportional hazards was performed to control for age, sex, race, grade, surgical margins, type of surgery, year of diagnosis, Charlson/Deyo Score, insurance, facility type, and location. Results: 651 patients with typical carcinoid (CT), 239 atypical carcinoid (ACT), 426 large cell neuroendocrine carcinoma (LCNEC), and 366 neuroendocrine carcinoma (NEC) were analyzed. The cohort median age was 61, and the female:male ratio was 1.8 for CT, ACT and NEC, and 1 for LCNEC 90% of patients were White and there were no significant differences amongst histologic subtypes. 6% of patients with CT received ADJ-CT, compared to 40% ACT, 42% NEC, and 70% LCNEC. In a multivariate analysis, only increasing age was associated with worse prognosis across all histologic subtypes, and non-academic facility for CT, and male sex for NEC. ADJ-CT was not associated with OS benefit for patients with ACT (HR 1.1; 95% CI 0.68-1.78; p:0.6), was associated with inferior OS in CT (HR: 3.8 (95% CI 1.9-7.0; p = 0.004) and NEC (HR: 2.15; 95% CI 1.5-3.0; p < 0.001), and may provide benefit for LCNEC (HR: 0.67; 95% CI 0.5-0.9; p = 0.009). Conclusions: Adjuvant chemotherapy was not associated with survival benefit for patients with node positive and non-metastatic BNET except for LCNEC, and may be harmful for patients with CT and NEC.

Abstract Background: In stage IV non-small cell lung cancer (NSCLC), survival has significantly improved with the use of novel therapies and better supportive care. Despite such trends, it has been noted that patients (pts) frequently refuse cancer treatment. Therefore, we explored the factors associated with treatment refusal in pts with stage IV NSCLC. Methods: Utilizing the National Cancer Database (NCDB), we identified all incident cases with stage IV NSCLC from 2004 to 2014. Patients who received cancer treatment outside of the reporting facility or died before receiving treatment were excluded. Multivariable logistic regression models were used to determine associations with treatment refusal. Results: A total of 341,993 pts were identified. On average, 5.4% of pts refused radiation therapy and 10.3% refused chemotherapy despite provider recommendations. The proportion of pts refusing radiation and chemotherapy increased over the study period from 4.2% to 7.3% and 7.9% to 15%, respectively (p&lt;0.001 for both). In multivariable analysis, men were less likely to refuse radiation or chemotherapy compared to women (OR: 0.82, 95%CI: 0.76-0.83, p&lt;0.001; OR: 0.84, 95%CI: 0.81-0.86, p&lt;0.001, respectively). Factors associated with radiation therapy refusal included: Medicaid or Medicare as primary insurance (OR: 1.95, 95%CI: 1.76-2.15, p&lt;0.001; OR: 1.25, 95%CI: 1.17-1.34, p&lt;0.001, respectively) or a &gt;2 Charlson Comorbidity Index (OR: 1.97, 95%CI: 1.85-2.10, p&lt;0.001). Moreover, receiving care at an academic center (OR: 0.57, 95%CI: 0.53-0.62, p&lt;0.001) was associated with less likelihood of refusing radiation. Regarding chemotherapy, uninsured pts (OR: 2.45, 95%CI: 2.26-2.66, p&lt;0.001), pts with Medicaid as primary insurance (OR: 2.17, 95%CI: 2.03-2.32, p&lt;0.001) or with a high comorbidity index (OR: 1.76, 95%CI: 1.68-1.84, p&lt;0.001) were more likely to refuse chemotherapy. Contrary to findings from previous studies, Non-Hispanic Blacks and Hispanics were less likely to refuse chemotherapy compared to non-Hispanic whites (OR: 0.86, 95%CI: 0.82-0.91, p&lt;0.001; OR: 0.78, 95%CI: 0.72-0.89, p&lt;0.001). Patients receiving care at an academic center and residing in high income neighborhoods were less likely to refuse chemotherapy (OR: 0.76, 95%CI: 0.72-0.80, p&lt;0.001; OR: 0.76, 95%CI: 0.71-0.81, p&lt;0.001, respectively). Distance from residence to treating facility and living in a rural county did not affect treatment refusal. Conclusions: Socioeconomic factors rather than race/ethnicity appear to influence refusal of cancer treatment in pts with stage IV NSCLC in the NCDB. Assessing socioeconomic challenges should be an essential part of patients' evaluation when discussing treatment options. Citation Format: Narjust Duma, Urshila Durani, Ryan Frank, Jonas Paludo, Gustavo Westin, Yanyan Lou, Leventakos Konstantinos, Julian Molina, Ronald Go, Aaron Mansfield, Sikander Ailawadhi, Alex Adjei. Influence of sociodemographic factors on treatment decisions in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4230.

Background: Patients with end-stage kidney disease (ESKD) on dialysis were excluded from clinical trials of direct oral anticoagulants for atrial fibrillation (AF). Recent data have raised concerns regarding the safety of dabigatran and rivaroxaban, but apixaban has not been evaluated despite current labeling supporting its use in this population. The goal of this study was to determine patterns of apixaban use and its associated outcomes in dialysis-dependent patients with ESKD and AF. Methods: We performed a retrospective cohort study of Medicare beneficiaries included in the United States Renal Data System (October 2010 to December 2015). Eligible patients were those with ESKD and AF undergoing dialysis who initiated treatment with an oral anticoagulant. Because of the small number of dabigatran and rivaroxaban users, outcomes were only assessed in patients treated with apixaban or warfarin. Apixaban and warfarin patients were matched (1:3) based on prognostic score. Differences between groups in survival free of stroke or systemic embolism, major bleeding, gastrointestinal bleeding, intracranial bleeding, and death were assessed using Kaplan–Meier analyses. Hazard ratios (HRs) and 95% CIs were derived from Cox regression analyses. Results: The study population consisted of 25 523 patients (45.7% women; 68.2±11.9 years of age), including 2351 patients on apixaban and 23 172 patients on warfarin. An annual increase in apixaban prescriptions was observed after its marketing approval at the end of 2012, such that 26.6% of new anticoagulant prescriptions in 2015 were for apixaban. In matched cohorts, there was no difference in the risks of stroke/systemic embolism between apixaban and warfarin (HR, 0.88; 95% CI, 0.69–1.12; P =0.29), but apixaban was associated with a significantly lower risk of major bleeding (HR, 0.72; 95% CI, 0.59–0.87; P <0.001). In sensitivity analyses, standard-dose apixaban (5 mg twice a day; n=1034) was associated with significantly lower risks of stroke/systemic embolism and death as compared with either reduced-dose apixaban (2.5 mg twice a day; n=1317; HR, 0.61; 95% CI, 0.37–0.98; P =0.04 for stroke/systemic embolism; HR, 0.64; 95% CI, 0.45–0.92; P =0.01 for death) or warfarin (HR, 0.64; 95% CI, 0.42–0.97; P =0.04 for stroke/systemic embolism; HR, 0.63; 95% CI, 0.46–0.85; P =0.003 for death). Conclusions: Among patients with ESKD and AF on dialysis, apixaban use may be associated with a lower risk of major bleeding compared with warfarin, with a standard 5 mg twice a day dose also associated with reductions in thromboembolic and mortality risk.

Key Points Using the largest set of patients with newly diagnosed myeloma, we identified 63 mutated driver genes. We identified oncogenic dependencies, particularly relating to primary translocations, indicating a nonrandom accumulation of genetic hits.