Is There A Role For Older-Patient-Specific Cancer Clinical Trials? A Pooled Analysis Of 2277 Older Patients In Adjuvant Breast Cancer Trials (Alliance A151715)

10034 Background: Breast cancer incidence increases with age, but older patients tend to be underrepresented in clinical trials. To address this underrepresentation, this study examined the role of older-patient-specific trials – defined as those designed explicitly for older cancer patients. Methods: This study focused on patients 65 years of age or older (younger patients in age-unspecified trials were excluded). It included all Alliance phase III adjuvant breast cancer trials conducted from 1985-2012, encompassing older-patient-specific trials (CALGB 49907 and NCCTG 89-30-52; the latter was the only hormonal trial) and age-unspecified trials (CALGB 40101, NCCTG 9831, CALGB 9741, CALGB 9344, and CALGB 8541). Comparisons were based on trial type (older-patient-specific versus age-unspecified). Results: 2277 older patients were included (1014 from older-patient-specific trials; 1263 from age-unspecified trials). The cohort of older-patient-specific trials compared to the cohort of age-unspecified trials comprised a greater percentage of patients 75 year of age or older: 26% versus 6% (p < 0.0001) with a median age (range) of 72 years (65, 89) and 68 years (65, 84), respectively, (p < 0.0001). Median overall survival (OS) was comparable: 12.8 years (95% confidence interval (CI): 11.9-13.7 years) and 13.5 years (95% CI: 12.9-14.1 years) in older-patient-specific trials and age-unspecified trials, respectively. After adjusting for age, estrogen receptor status, tumor size, and positive lymph nodes, OS remained comparable (hazard ratio 0.9; 95% CI: 0.8-1.0; (referent: older-patient-specific trials; performance score excluded from the model due to missing data)). Similar conclusions were reached for recurrence-free survival. Older-patient-specific trials had lower grade 2-5 adverse event rates (68% versus 73%; p = 0.03). Sensitivity analyses with only chemotherapy trials (NCCTG 89-30-52 excluded) yielded similar findings. Conclusions: Older-patient-specific trials appear to help address the underrepresentation of older patients in cancer clinical trials. Support: UG1CA189823, U10CA180821, U10CA180882