Trends in chemotherapy utilization for colorectal cancer

Since 1990, significant advances have occurred in the adjuvant and metastatic treatment of colorectal cancer (CRC). Not all patients may be eligible for chemotherapy (CT), and the proportions and characteristics of patients who receive treatment are not well defined. In this study, treatment patterns of patients referred to the British Columbia Cancer Agency (BCCA) with early-stage colon cancer and metastatic CRC between 1990 and 2004 are described.

This study included patients with stage II or III colon cancer or stage IV CRC at presentation referred to the BCCA during a 1-year period for 3 time cohorts: 1990, 2000, and 2004. Patients were considered treated with CT if they received > or = 1 cycle of any CT for indication of the initial referral diagnosis.

A total of 1421 patients were included: stage II/III, n = 915; stage IV, n = 506. Chemotherapy utilization increased significantly from 1990 to 2004 for adjuvant CT (1990: 29%; 2000: 45%; 2004: 52%; P < .001) and for palliative CT (1990: 35%; 2000: 51%; 2004: 63%; P < .001). The proportion of patients with stage II disease treated with adjuvant CT dramatically increased (1990: 4%; 2000: 26%; 2004: 30%; P < .001). The use of palliative CT was significantly associated with male sex (P = .025). Among older patients, only 25% received adjuvant CT, and 31% received palliative CT.

In this population-based study, adjuvant and palliative CT utilization increased significantly between 1990 and 2004. The majority of patients aged > 70 years did not receive CT, and women appeared less likely to receive palliative CT. Such disparities in CT utilization require further investigation.