Abstract B77: Asian-American response to pemetrexed: Results from an observational study of second-line treatment of non-small cell lung cancer.

Background: The association of race with clinical outcomes has been increasingly investigated in non-small cell lung cancer (NSCLC). This prospective observational study evaluated the impact of race on disease control rate (DCR) in patients with NSCLC treated with second-line pemetrexed. Our previous report of this study showed the DCR of African-Americans was non-inferior to that of Caucasians (C). This report compares outcomes for Asian-Americans (AS) and C.

Methods: Patients with stage IIIB/IV NSCLC who received one prior chemotherapy regimen and second-line therapy with pemetrexed were eligible. The primary endpoint was DCR (complete/partial response or stable disease). Secondary endpoints were overall survival (OS), progression-free survival (PFS), and adverse events. Logistic regression was used to analyze the DCR after therapy, controlling for 15 predefined covariates including prognostic and socioeconomic factors. Survival was estimated using Kaplan-Meier and compared with a log-rank test. Analyses were not adjusted for multiple race comparisons.

Results: Challenges in enrolling minorities led to a lower than anticipated enrollment (AS=37 vs. 200 planned; C=304 vs. 400 planned), leaving a small sample size from which to draw conclusions. The mean age was 65 years (range, 34-90) for AS and 66 years (range, 37-86) for C. There were 17 males/20 females in the AS group and 161 males/143 females in the C group. Most patients had stage IV disease (AS=78.4%; C=80.3%). A higher percentage of AS had adenocarcinoma (AS=89.2%; C=62.8%; p=0.004) and a higher percentage of C were current smokers (AS=0.0%; C=27.7%; p=0.0002). The mean number of cycles received was 5.8 for AS and 4.1 for C. For the evaluable patients (AS=30; C=268), the DCR was numerically higher for AS (53.3% vs. 43.7%, OR=0.609, 95% CI: 0.253-1.469), but this difference was not statistically significant (p=0.270). AS had a significantly longer unadjusted median OS and PFS than C: OS of 16.0 (95% CI: 5.75-16.0) vs. 6.73 months (95% CI: 5.65-7.92), p=0.041; PFS of 5.08 (95% CI: 2.50-11.1) vs. 2.66 months (95% CI: 2.40-3.35), p=0.045. Adverse events, regardless of causality, occurred in <15% of patients, except for fatigue (AS=60%; C=68%).

Conclusions: Despite the small sample size, this study provides insight into characteristics and outcomes of AS treated with second-line pemetrexed.

Citation Format: A A. Adjei, E Pennella, A C. Girvan, G Peltz, G Pohl, C Obasaju, K Winfree, M S. Walker, E J. Stepanski, L S. Schwartzberg. Asian-American response to pemetrexed: Results from an observational study of second-line treatment of non-small cell lung cancer. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr B77.