Disparities in the use of chemotherapy and monoclonal antibody therapy for elderly advanced colorectal cancer patients in the community oncology setting

Abstract

Background: The clinical trials on which the treatment of advanced colorectal (CRC) is based enroll few elderly patients. Furthermore, few investigations have determined the use and outcomes of the treatment of advanced CRC in practice. This study evaluated the treatment of advanced CRC in community oncology practices, focusing on age-related differences in treatment and outcome.

Methods: A national, retrospective chart review was conducted to evaluate the management of advanced CRC in 10 community practices across the U.S. All medical records of patients diagnosed with advanced CRC initiating chemotherapy treatment after January 1, 2003 through 2006 were included. The primary aim was to compare the proportion receiving doublet chemotherapy (irinotecan or oxaliplatin with a fluoropyrimidine) as initial therapy in young (age <or=65 years) and elderly (age >65 years) patients. Additional aims included age-based comparisons of the addition of bevacizumab to chemotherapy, overall chemotherapy use, all-cause mortality, and toxicity-related events.

Results: Overall, 520 patients (56% elderly) received 6,253 cycles of chemotherapy. Of the younger patients, 84% received doublet chemotherapy first-line, compared with 58% of elderly patients (p < .001). The use of each of the medications--irinotecan, oxaliplatin, and bevacizumab--was lower in elderly patients (p < .001). Independent predictors of a higher risk for mortality were age >65 (adjusted hazards ratio [HR],1.19; 95% confidence interval [CI], 1.02-1.39) and performance status score >or=2 (HR, 1.65; 95% CI, 1.41-1.91).

Conclusion: Elderly patients are less likely to receive first-line doublet chemotherapy than younger patients. Age and performance status are independent predictors of treatment and overall survival.