Improvement in survival of metastatic colorectal cancer: are the benefits of clinical trials reproduced in population-based studies?

Abstract

Aim of the study: To describe trends in survival of non-resectable metastatic colorectal cancer (MCRC) over a 34-year period in a French population-based registry taking into account major advances in medical therapy.

Patients and methods: 3804 patients with non-resectable metastatic colorectal cancer diagnosed between 1976 and 2009 were included. Three periods (1976-96, 1997-2004 and 2005-09) were considered.

Results: The proportion of patients receiving chemotherapy dramatically increased from 19% to 57% between the first two periods, then increased steadily thereafter reaching 59% during the last period (p<0.001). Median relative survival increased from 5.9 months during the 1976-96 period to 10.2 months during the 1997-2004 period but, despite the availability of targeted therapies, remained at 9.5 months during the 2005-09 period. During the last study period, less than 10% of elderly patients received targeted therapies compared to more than 40% for younger patients. Their median relative survival was 5.0 months compared to 15.6 months in younger patients.

Conclusion: There was an improvement in survival in relation with the increased use of more effective medical treatment. However, at a population-based level, patients are not all treated equally and most of them, especially the elderly, do not benefit from the most up-to-date treatment options.

Keywords: Chemotherapy; Colorectal cancer; Elderly; Population-based study; Survival; Targeted therapies.