Few physicians refer patients to cancer clinical trials

Although more than 8000 clinical trials are accepting participants, according to the National Cancer Institute (NCI), only an estimated 2%-4% of newly diagnosed cancer patients participate in them. Prior studies suggest that most eligible patients do not enroll in trials because their physicians do not refer them.

To understand what types of physicians are referring their patients to clinical cancer trials, Carrie N. Klabunde, Ph.D., of NCI, and colleagues, conducted a survey-based study of specialty physicians caring for colorectal and lung cancer patients. The researchers analyzed data from the Cancer Care Outcomes Research and Surveillance Consortium (CanCORS) for 1533 oncologists, radiation oncologists, and surgeons caring for colorectal and lung cancer patients. The physicians had completed a survey during 2005-2006.

The researchers found that 869 of the physicians, or 56.7%, responded that they had referred or enrolled at least one patient in clinical trials in the previous 12 months: 87.8% of medical oncologists, 66.1% of radiation oncologists, and 35% of surgeons. Two-thirds of the physicians affiliated with a Community Clinical Oncology Program or an NCI-designated cancer center reported participating in trials.

Furthermore, the researchers write, "Those more likely to participate in a clinical trial were medical or radiation oncologists (vs surgeons), were in larger practices, had academic appointments, saw a higher volume of lung or colorectal cancer patients, and attended weekly tumor board meetings."

The researchers also found that among the physicians who reported referring or enrolling at least one patient in cancer clinical trials in this period, the mean number of patients referred or enrolled was 17.2 for medical oncologists, 9.5 for radiation oncologists, and 12.2 for surgeons. The researchers note that primary care physicians have limited involvement in discussing clinical trial participation with patients; and that financial incentives were associated with physicians' clinical trials accrual volume, a finding consistent with previous studies showing financial incentives influence physician behavior.

The researchers point out certain limitations of their study: the physicians surveyed do not comprise a nationally representative sample; the study is based on physicians' self-reports of their participation in clinical trials; and the measure of trials participation combined patient referral and enrollment.

The researchers conclude that continued monitoring of physician participation in cancer clinical trials is essential. They write, "More research is needed to better understand clinician attitudes toward clinical research and to examine specific features of practice infrastructure -- including availability of support staff, electronic health records, reimbursement, and clinical trial databases -- that facilitate or hinder physician participation in clinical trials."

In an accompanying editorial, Lori M. Minasian, M.D., and Ann M. O'Mara, M.D., of the Community Oncology and Prevention Trials Research Group at the National Cancer Institute (NCI), write that "the American public continues to value medical research," and cite a Mayo clinic study in which 76% of patients said they expected their treating physician to inform them about clinical trials.

The authors also point out that medical students will be required to learn about clinical and translational research, according to a new standard from the Liaison Committee on Medical Education.

The authors conclude: "If we want research to inform practice, we need a workforce of physicians who value the research and understand how to incorporate research results into their practice. Much of the American public looks to their physicians to do that."