Treatment tolerance and efficacy in geriatric oncology: a systematic review of phase III randomized trials conducted by five National Cancer Institute-sponsored cooperative groups

Abstract

Purpose: Elderly patients share the majority of the disease burden in cancer. Although 61% of new cancer cases occur among elderly, they comprise only 25% of the patients enrolled onto randomized clinical trials (RCTs). A systematic review to assess the accurate participation of elderly patients in RCTs has not been performed.

Patients and methods: We reviewed all consecutively completed phase III RCTs conducted by five National Cancer Institute-sponsored cooperative groups. Published papers and study protocols were used for data extraction. We used a cutoff age of 65 years to define elderly patients. For trials that did not exclusively enroll elderly, data were extracted on number of participants 65 years of age. Outcome between the innovative and the standard treatment was compared.

Results: Of 345 studies, only one trial exclusively enrolled elderly patients (0.28%); 57% of the trials (n = 197) had no stratification by age, and 12% of the studies had a stratification age 65 years (n = 42). Overall survival in the trial exclusively enrolling elderly favored the newer treatments (hazard ratio [HR], 0.69; 95% CI, 0.47 to 1.02; P = .06). Additionally, in trials enrolling more than 40% of elderly, survival and event-free survival favored the innovative treatments (HR for survival, 0.91; 95% CI, 0.84 to 0.99; P = .03; HR for event-free survival, 0.85; 95% CI, 0.72 to 1.01; P = .07). Treatment-related mortality was similar in both the innovative and standard treatment groups (HR, 0.91; 95% CI, 0.47 to 1.78; P = .8).

Conclusion: Our data indicate that enrollment of elderly in experimental RCTs is not associated with increased harm to this patient population. Increased participation of elderly may help in finding new treatments that are clinically applicable specifically to this cohort of patients.