Who enrolls onto clinical oncology trials? A radiation Patterns Of Care Study analysis

To identify factors significantly influencing accrual to clinical protocols by analyzing radiation Patterns of Care Study (PCS) surveys of 3,047 randomly selected radiotherapy (RT) patients.

Patterns of Care Study surveys from disease sites studied for the periods 1992-1994 and 1996-1999 (breast cancer, n = 1,080; prostate cancer, n = 1,149; esophageal cancer, n = 818) were analyzed. The PCS is a National Cancer Institute-funded national survey of randomly selected RT institutions in the United States. Patients with nonmetastatic disease who received RT as definitive or adjuvant therapy were randomly selected from eligible patients at each institution. To determine national estimates, individual patient records were weighted by the relative contribution of each institution and patients within each institution. Data regarding participation in clinical trials were recorded. The factors age, gender, race, type of insurance, and practice type of treating institution (academic or not) were studied by univariate and multivariate analyses.

Overall, only 2.7% of all patients were accrued to clinical protocols. Of these, 57% were enrolled on institutional review board-approved institutional trials, and 43% on National Cancer Institute collaborative group studies. On multivariate analysis, patients treated at academic facilities (p = 0.0001) and white patients (vs. African Americans, p = 0.0002) were significantly more likely to participate in clinical oncology trials. Age, gender, type of cancer, and type of insurance were not predictive.

Practice type and race significantly influence enrollment onto clinical oncology trials. This suggests that increased communication and education regarding protocols, particularly focusing on physicians in nonacademic settings and minority patients, will be essential to enhance accrual.