Substantial Proportion of Lung Cancer Patients Excluded from Clinical Trials Due to Prior Cancer

Study finds stringent eligibility criteria is creating a barrier for patient enrollment.

A history of prior cancer has caused a substantial proportion of lung cancer patients to be excluded from clinical trials, according to the results of a recent study.

Published on September 26, 2014 in the Journal of the National Cancer Institute, researchers examined more than 50 lung cancer clinical trials to find that more than 80% excluded patients who had prior cancer. The study noted that even in trials in which survival was not the primary endpoint, more than two-thirds of patients with prior cancer were still left out.

"Our research demonstrates that a substantial proportion of potential subjects are reflexively excluded from lung cancer clinical trials due to prior cancer," said lead author David Gerber, MD, in a press release. "The resulting impact on study accrual is sobering."

The study found that prior cancer was apparently the only reason for study ineligibility in numerous trials, even though the past instance of the disease seemed unlikely to interfere with treatment or outcomes.

For the study, researchers examined lung cancer trials through a National Cancer Institute-funded organization, in which the eligibility criteria for patients with prior cancer carried vast differences between trials. The study found that 43% of trials excluded patients who were diagnosed with cancer within 5 years of enrollment; 16% of trials excluded patients who have active cancer; 14% excluded patients with any history of cancer; and 7% excluded patients who had cancer within the past 2 to 3 years.

The findings raise concerns due to the fact that there has been a four-fold increase over the past 30 years in cancer survival, with more than 13 million cancer survivors currently living in the United States. Less than 2% of adults currently participate in clinical trials, as strict eligibility criteria represents a significant key hurdle in patient enrollment, in addition to limited access to clinical trials and the lack of patient interest, the study noted.

The exclusion of cancer survivors is an issue because randomized clinical trials tend to focus on a narrow and homogenous group of cancer patients, according to the study authors. With improvements in the treatment of cancer and other life-threatening diseases, there has subsequently been an increase to the population of long-term survivors.

As such, the authors note, it is vital to include these survivors in cancer trials so the information concerning the efficacy of cancer treatments in this growing subgroup is more representative.

"If future studies demonstrate that prior cancer does not limit lung cancer treatment options or adversely impact clinical outcomes, modifying or eliminating this longstanding and arbitrary exclusion policy in lung cancer clinical trials may result in more generalizable results, faster accrual, higher completion rates, and the delivery of better treatments to more patients sooner," Dr. Gerber said. "Because clinical trial design is relatively centralized, we believe that implementation of such changes could occur rapidly.”