Never too old? Age should not be a barrier to enrollment in cancer clinical trials

Abstract

Throughout Europe and the U.S., over 60% of the total incidence of cancer occurs in the elderly (> or =65 years) population, a patient group that requires particular consideration when making treatment decisions due to a number of factors. Despite this, elderly patients are generally under-represented in clinical trials such that study data should be interpreted with caution because results in younger cancer patients may not always extrapolate to the typical elderly cancer patient. Reports suggest that elderly cancer patients represent around 22% of patients enrolled in phase II clinical studies. Barriers to the accrual of elderly patients to clinical trials include lack of appropriate trials, high burden of comorbidity, study-imposed restrictions, and attitudes of physicians. There is a belief that elderly patients may be unable to tolerate various cancer therapies, which may result in this patient population being excluded from prospective trials. However, clinical data demonstrate that age alone is not a sufficient reason to withhold treatment. Lack of clinical trial data and the associated lack of evidence-based guidelines for elderly patients mean physicians have little to guide them, with the result that patients may not receive the optimal therapy. As clinical trials are the primary method of evaluating the efficacy and safety of adjuvant and palliative cancer therapies, trials that specifically target the elderly cancer patient are required to adequately assess the risks and benefits of treatment in this vulnerable population. This review aims to assess the clinical reality and clinical trial age mismatch to evaluate implications for elderly cancer patients and to identify how this situation may be addressed. Possible reasons for the disparity, and the resulting clinical consequences, are also considered.