Clinical trials are conducted in patients with cancer in order to determine the optimal treatment for a patient population. This might include evaluation of a new therapeutic agent, best use of an existing drug or intervention, assessment of safety, or identification of which patients are most likely to benefit from treatment.1 The information gained from such studies may be submitted to regulatory authorities and inform best practice guidelines, and will often be required to make decisions on whether an intervention may be funded by those commissioning healthcare. However, a unifying feature of these applications of clinical trial results is that the evidence base is established in a population that is representative of the population we are planning to treat. Unfortunately, this is not necessarily the case when considering the care of older patients with cancer.2
At present, more than 160,000 people aged 70 and over are diagnosed with cancer every year in the UK, representing 50% of all cancer diagnoses.3 With the ageing of the population, both the proportion of cancers diagnosed in older patients and the absolute number of cancer diagnoses in this patient group are likely to rise, such that by 2030 it is anticipated that 70% of cancers will occur in people aged over 65,4 with very similar projections for the USA.5 Therefore, attending to the needs of the increasingly large population of older patients with cancer must become a priority for those involved in cancer care, and this should include recruitment to clinical trials in order to inform best care.
Are older patients with cancer represented in clinical trials?
Several studies have shown that recruitment of older patients to clinical trials is not in proportion to the age distribution of the cancer population.6,7 A 2004 analysis reported on the recruitment of older patients to registration trials of new drugs or new indications approved by the US Food and Drug Administration between 1995 and 2002.7 The proportion of the trial populations aged >65, >70 and >75 years were 36%, 20% and 9%, compared with 60%, 46% and 31%, respectively, in the US cancer population. Statistically significant underrepresentation of the older patient was noted for all cancer treatments except for breast cancer hormonal therapies.7 Similar observations can be made regarding trials on the Cancer Research UK portfolio (Figures 6.1, 6.2, 6.3), providing further evidence that older patients are underrepresented in clinical trials.
Breast cancer studies: comparing trial populations with a general population undergoing cancer therapy. TACT-2, adjuvant chemotherapy: 2 vs 3 weekly epirubicin + CMF (cyclophosphamide, methotrexate and 5-FU) or capecitabine;30 Import Low (ClinicalTrial.gov registration no. NCT00814567), different ways of giving radiotherapy for low-risk early-stage breast cancer; SOFEA, fulvestrant +/− anastrozole vs exemestane in postmenopausal women with metastatic breast cancer;31 TNT (ClinicalTrial.gov registration no. NCT00532727), chemotherapy for advanced ...