Patterns of care among veterans with colon cancer: Insights from California SEER, Medicare and VA-linked data

Abstract

6586 Background: U.S. veterans have been shown to be a vulnerable population with high cancer rates, yet practice pattern information is lacking. Linkage of cancer registry, Medicare, and VA data provides a more complete view of health status and healthcare received among veterans with cancer. Methods: As part of a national study, a retrospective cohort of incident colon cancer patients from the California Cancer Registry data, who were = 66 years old and eligible to use VA and Medicare between 1999 and 2001, were followed for three years through 2004. We examined practice patterns for stages I-IV colon cancer, specifically, surgery and use of chemotherapy, and trends in one-year mortality using descriptive and multivariate regression models. Results: Among 633 veterans with colon cancer, 93% were male; 16% were African American; 28% were diagnosed at a VA facility compared to 72% at a Medicare facility, and 553 (87%) had colectomy. One year mortality rate was 29%. Among the 553 colectomy patients, prevalence of chemotherapy use, according to stage was 8%, 27%, 61% and 52% for stages I-IV, respectively (p-value <0.0001). Regression analyses of factors affecting whether chemotherapy was received revealed that Stage III patients were most likely to receive adjuvant chemotherapy (Odds Ratio (OR) 19.80, 95% Confidence Interval (CI): 9.68–40.50). However stage II and stage IV patients were also highly likely to receive chemotherapy following surgery (OR: 4.41 CI: 2.18–8.91 and OR: 13.21; CI: 6.01–29, respectively). Patients =76 years and those =86 years were less likely to receive chemotherapy following surgery (OR: 0.61, CI: 0.40–0.94 and OR: 0.25, CI: 0.094–0.64, respectively) compared to patients 66–75 years. Patients with Charlson Comorbidity Score of 2 or greater were less likely to receive chemotherapy (OR: 0.49; CI: 0.29–0.84). Treating facility (VA or Medicare), did not affect chemotherapy use. Conclusions: Among veterans with colon cancer in California, older patients were less likely to receive chemotherapy even when stage and comorbidity status were considered. Efforts focused on improving guideline consistent adjuvant chemotherapy use among older veterans with stage III colon cancer across treating facilities may yield the greatest benefit. No significant financial relationships to disclose.