Key words
Cancer, clinical trial participation, older patients. (Definitions of many terms related to cancer can be found in the Cancer.gov Dictionary.)
Summary
The authors of this report systematically review what’s known about the barriers preventing older patients from taking part in cancer clinical trials. Persons over the age of 65 make up the largest proportion of cancer patients, but are underrepresented in trials of new treatments. The authors recommend changes in the way trials are designed and conducted in order to improve the recruitment of older patients.
Source
Journal of Clinical Oncology, May 1, 2005 (see the journal abstract).
Background
Although most new cases of cancer occur in persons age 65 and over, relatively few elderly patients take part in clinical trials of new cancer treatments. Identifying and lowering those barriers should help researchers do a better job of developing treatments that work in the population that needs them most.
The Study
Researchers in Canada searched English-language medical journals for articles published between 1994 and 2004 that described studies whose primary aim was to learn more about barriers keeping the elderly out of cancer clinical trials and what changes are needed to overcome those barriers. From an initial list of 159 articles the authors identified nine studies that met their criteria.
The study’s senior author is Lillian L. Siu, M.D., of Princess Margaret Hospital in Toronto, Canada.
Key Barriers
A table listing the nine studies is included in the full report. After reviewing all of them in depth, the authors concluded that underrepresentation of older patients is a problem for all cancer clinical trials. Most trials have requirements for participation that disproportionately exclude older patients. For example, most trials
- exclude people who have heart, kidney, liver, or blood abnormalities.
- exclude anyone who has had a previous cancer.
- require participants to be mobile and able to work, or able to live independently.
Doctors most often cited health problems and potential side effects from treatment as barriers to the enrollment of older patients in clinical trials. By contrast, older patients did not consider their age an important reason for not joining a trial.
For both older and younger patients, the main reason given for not taking part in a clinical trial was wanting to choose their own treatment. (In most clinical trials, participants are assigned – often at random – to a particular treatment for purposes of the study. Of course, patients can change or end their treatment at any time, but then their results may not be included in the trial’s final analysis.)
Strategies for Improvement
The study authors conclude that recruitment of older patients into cancer clinical trials could be improved by
- conducting clinical trials specifically for older patients, to document their ability to tolerate treatment and the effects of other health conditions.
- changing study designs so that, for example, patients are grouped by age. This would ensure that older patients are compared with other older patients rather than with younger patients.
- reconsidering the necessity of policies that exclude patients with other health conditions or previous cancers.
- assessing patients better to distinguish the “well” older patient from the “frail” older patient.
- making it easier for doctors and patients to find cancer trials of potential interest. For example, in June 2004, the Centers for Medicare and Medicaid Services (CMS) and the National Cancer Institute announced a joint effort to identify high-priority cancer trials in which elderly patients might want to enroll. (For more information, see Medicare Coverage of Clinical Trials.)
- providing additional resources so that research staff can devote extra time and effort to recruiting older patients.
- educating doctors about the treatment of cancer in older patients and about how to identify older patients who are good candidates for clinical trials.
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