Key words:

Clinical trial participation, older cancer patients. (Definitions of many terms related to cancer can be found in the Cancer.gov Dictionary.)

Summary:

A large study by the U.S. Food and Drug Administration (FDA) reinforces earlier findings that, although most patients diagnosed with cancer are aged 65 or older, relatively few older patients with cancer are enrolled in clinical trials of new cancer treatments in the United States.

Source:

Journal of Clinical Oncology, Nov. 15, 2004 (see the journal abstract).

Background:

Most cancers are diagnosed in people over the age of 65. However, a number of studies have shown that older people are underrepresented in cancer clinical trials, leading some researchers to worry that perhaps new treatments are not being adequately tested on this population.

The Study:

Researchers from the FDA studied information on 29,350 patients who had been enrolled in clinical trials of new cancer drugs or new uses for existing drugs. All of the drugs were approved by FDA between 1995 and 2002. They compared the number of patients aged over 65 who were enrolled in these trials with the proportion of patients in the overall population who are aged over 65 and were diagnosed with one of six types of cancer: breast, lung, colorectal, pancreatic, and ovarian cancer and leukemia.

The results from this study were originally presented at the 2003 American Society of Clinical Oncology (ASCO) annual meeting.

Results:

The researchers found that, overall, although 60 percent of patients with one of these six cancer types are aged 65 and older, only 36 percent of patients enrolled in the clinical trials were in that age group. The size of the discrepancy varied by type of cancer. For example, although 71 percent of pancreatic cancers are diagnosed in patients 65 and older, only 33 percent of patients enrolled in trials of therapies for pancreatic cancer were in that age group.

By contrast, 44 percent of all ovarian cancers occur in women 65 and older while 31 percent of enrollees in the trials studied by FDA were in that age group.

“Clinical trials are the primary method of testing the safety and effectiveness of new cancer treatments,” said Lilia Talarico, MD, of FDA’s Center for Drug Evaluation and Research, who was the lead author for the study. “It is important that clinical trials enroll adequate numbers of patients who are representative of the population that may benefit from the treatment being studied. Underrepresentation of older patients in clinical trials does not allow us to assess the risks and benefits of many treatments in this population.”

Special studies targeted to patients aged 65 and over may be needed to identify the safest and most effective drugs, and the best ways to use those drugs, in this population, Talarico suggested.

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