Barriers to Clinical Trial Enrollment

June 1, 2001

Most patients do not want to use investigational treatments even though entry into cancer clinical trials is frequently associated with a higher survival rate. This is just one of the reasons why patients do not participate in trials, according to researchers at

Most patients do not want touse investigational treatmentseven though entry into cancer clinical trials is frequently associated with ahigher survival rate. This is just one of the reasons why patients do notparticipate in trials, according to researchers at the University of CaliforniaDavis Cancer Center, who conducted a study to determine the barriers to cancerclinical trial enrollment.

"Understanding the reasons why few patients ultimatelyenroll in cancer clinical trials is the first step to reversing the trend,"according to Primo Lara, Jr, MD, assistant professor of medicine at theUniversity of California Davis Cancer Center and lead author of the study, whichwas recently reported in the Journal of Clinical Oncology (19:1728-1733, 2001).

Physician Referrals

While the overall accrual rate of 14% for trial participation inthis investigation was better than the national average of 2% to 4%, researchersfound that physicians failed to refer approximately 38% of the 276 patientsstudied even before reviewing their eligibility. Doctors assumed that noclinical trial was available or that patients were too sick to be included.However, there were more than 100 clinical trials available at the cancer centerfor various tumor types during the study period and, according to theresearchers, some of the excluded patients may have been eligible.

Patients’ Participation

Of the 76 patients who met eligibility criteria and wererecommended by their physicians to participate in a clinical trial, nearly half(49%) refused to participate. Of these patients, 34% said they did not want touse investigational treatments, 13% said they lived too far from the cancercenter, and 5% feared randomization.

Insurance Coverage

In this study, 8% of patients were denied coverage by theirprivate insurance company for the costs associated with the trial. Moreover,patients with private health insurance were found to be less likely toparticipate in cancer clinical trials compared to those with governmentinsurance.

The issue of insurance reimbursement is problematic and bestaddressed through federal legislation, according to Dr. Lara. He also expressedconcern that insurers will increasingly deny coverage until effectivelegislation on mandatory third-party coverage for the routine costs of clinicaltrials is passed.

"Cancer clinical trials are essential for improvingoutcomes in cancer patients," Dr. Lara concluded. "The barriers toparticipation we’ve identified could be reduced through patient and physicianeducation and by providing access to clinical trials through programs that arecloser to where people live."