Gender Differences in Colon Cancer Treatment

Background: Despite women suffering a disproportionate burden of colon cancer mortality, few studies have examined gender differences in evidence-based treatment, especially in poorer states like Alabama. Objective: To describe colon cancer treatment in older patients diagnosed in Alabama by gender. Methods: Colon cancer patients 65 years and older diagnosed in 2000-2002 were identified from the Alabama Statewide Cancer Registry (N=1785). Treatment was identified from Medicare claims for 1999-2003. Outcomes were (1) receipt of surgery and adjuvant 5-fluorouracil chemotherapy (5FU) and (2) 5FU treatment duration (0-4, 5-7, and >7 months). Generalized Estimating Equation (GEE) models were used to determine significant gender differences, adjusting for clustering at the reporting hospital level, and controlling for race, age, stage, comorbid conditions, census tract-level socioeconomic variables, and adverse chemotherapy effects (when analyzing 5FU duration). Results: Overall, 93.9% of the patients received surgery. Of stage II-III patients undergoing surgery, 60.4% stage III and 25.6% stage II patients received 5FU. Compared with men, women were more likely to have surgery (95.5% vs. 92.2%, p=0.003), less likely to have 5FU (38.6% vs. 45.2%, p=0.02), and more likely to have 0-4 months of 5FU (32.9% vs. 24.9%, p=0.05). Gender differences were significant for having chemotherapy (adjusted odds ratio [aOR] 0.78, confidence interval [CI] 0.61-1.00, p=0.049), but not for having 0-4 months of 5FU when adjusting for adverse effects (aOR 1.36, CI 0.95-1.94, p=0.09). Conclusions: In Alabama, some gender differences in stage-specific colon cancer treatment are worth further scrutiny.