Purpose: We chose to examine the impact of socioeconomic factors on accrual to National Cancer Institute (NCI)-sponsored cancer treatment trials.

Patients and methods: We estimated the geographic and demographic cancer burden in the United States and then identified 24,332 patients accrued to NCI-sponsored cancer treatment trials during a 12-month period. Next, we examined accrual by age, sex, geographic residence, health insurance status, health maintenance organization market penetration, several proxy measures of socioeconomic status, the availability of an oncologist, and the presence of a hospital with an approved multidisciplinary cancer program.

Results: Pediatric patients were accrued to clinical trials at high levels, whereas after adolescence, only a small percentage of cancer patients were enrolled onto clinical trials. There were few differences by sex. Black males as well as Asian-American and Hispanic adults were accrued to clinical trials at lower rates than white cancer patients of the same age. Overall, the highest observed accrual was in suburban counties. Compared with the United States population, patients enrolled onto clinical trials were significantly less likely to be uninsured and more like to have Medicare health insurance. Geographic areas with higher socioeconomic levels had higher levels of clinical trial accruals. The number of oncologists and the presence of approved cancer programs both were significantly associated with increased accrual to clinical trials.

Conclusion: We must work to increase the number of adults who enroll onto trials, especially among the elderly. Ongoing partnership with professional societies may be an effective approach to strengthen accrual to clinical trials.