Older-Patient-Specific Cancer Trials: A Pooled Analysis of 2,277 Patients (A151715)

Less than 3% of older patients with cancer are enrolled in clinical trials. To reverse this underrepresentation, we compared older patients enrolled with older-patient-specific trials, defined as those designed for older patients with cancer, with those enrolled in age-unspecified trials.

We focused on individual patient data from those ≥65 years (younger patients excluded) and included all Alliance phase III adjuvant breast cancer trials from 1985-2012.

Among 2,277 patients, 1,014 had been enrolled to older-patient-specific and 1,263 to age-unspecified trials. The median age (range) in the older-patient-specific trials was 72 (65-89) years compared with 68 (65-84) years in the cohort of older patients in age-unspecified trials; p < .0001. A greater percentage of patients 75 years or older had enrolled in older-patient-specific trials compared with the cohort of age-unspecified trials: 26% versus 6% (p < .0001). Median overall survival (OS) was 12.8 years (95% confidence interval [CI], 11.9-13.7) and 13.5 years (95% CI, 12.9-14.1) for older-patient-specific and age-unspecified trials, respectively. OS was comparable (hazard ratio [HR], 1.08; 95% CI, 0.92-1.28; p = .34; referent: age-unspecified trials), after adjusting for age, estrogen receptor status, tumor size, and lymph node status. Similar findings were reached for recurrence-free survival. A lower rate of grade 3-5 adverse events (hematologic and nonhematologic) was reported in older-patient-specific trials (43% vs. 58%; p < .0001). Sensitivity analysis with chemotherapy only trials and subset analysis, adjusted for performance score, yielded similar OS results.

Older-patient-specific trials appear to address this underrepresentation of older patients with ostensibly comparable outcomes. Clinical trial identification numbers. NCT00003088 (CALGB 9741); NCT00024102 (CALGB 49907); NCT00068601 (CALGB 40401); NCT00005970 (NCCTG N9831) IMPLICATIONS FOR PRACTICE: This work underscores the importance of clinical trials that focus on the recruitment of older patients with cancer.