Increasing underrepresentation of elderly patients with advanced colorectal or non-small-cell lung cancer in chemotherapy trials

Background: Elderly patients are underrepresented in chemotherapy trials for advanced colorectal cancer (CRC) and non-small-cell lung cancer (NSCLC). However, the change in underrepresentation over time has not been documented. Aims: This study aimed to quantify (i) the change in the median age of patients enrolled in clinical trials for metastatic CRC and NSCLC between 1982-1991 and 1992-2001 compared with the general colorectal and lung cancer population, and (ii) the proportion of trials with an upper age limit for eligibility. Methods: A retrospective review of data from the Victorian Cancer Registry and all large published randomized chemotherapy trials for advanced CRC and NSCLC between 1982 and 2001 was conducted. Results: The median age of patients with CRC enrolled in clinical trials remained constant between the two decades (62.0 and 62.2 years), whereas the median age of the CRC population increased from 68.4 to 70.2 years, increasing the median age difference from 6.4 to 8.0 years. The median age of patients with lung cancer in clinical trials increased from 59.8 to 61.8 years, whereas the median age of the lung cancer population increased from 67.4 to 70.4 years, widening the age difference from 7.6 to 8.6 years. More trials set an upper age limit for eligibility in the first decade than in the second decade for both CRC (51 vs 29%, P=0.04) and NSCLC (68 vs 41%, P=0.03). Conclusion: International clinical trials for CRC and NSCLC are becoming increasingly unsuitable for application to Australian patients because of the increasing age discrepancy, despite fewer trials restricting eligibility by age.