Survival of colorectal cancer patients hospitalized in the Veterans Affairs Health Care System

Abstract

Objectives A recent analysis based on data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute indicates that no survival benefit occurred, for white or for black individuals, in colorectal cancer diagnosed during 1986–1997, and that blacks fared worse than whites. The objective of this research was to evaluate recent temporal trends in the survival of patients with colorectal cancer admitted to hospitals in the Veterans Affairs (VA) system, which offers equal access to care and facilitates systemwide implementation of prevention and treatment services. Methods This research was a cohort study of patients admitted to all VA hospitals with a new diagnosis of colorectal cancer between October, 1987, and September, 1998, and followed through September, 2001. Temporal changes in observed 5-yr survival were evaluated for the periods 1987–1989, 1990–1992, 1993–1995, and 1996–1998. Cumulative survival was obtained from Kaplan-Meier estimates, whereas adjusted risk of death was calculated using a Cox proportional hazards model. Adjustment was made for differences in patient characteristics, including comorbidity. Results We identified 46,044 individuals with colorectal cancer in VA hospitals during 1987–1998, 98.5% of whom were men. The mean age was 67.7 yr, and the two largest racial/ethnic groups were whites (76.5%) and blacks (17.1%). Significant differences in survival were seen over time ( p < 0.001, log rank test) with longer survival in patients diagnosed in the more recent time periods. In the multivariable Cox model, survival showed an 18% increase over time (1987–1998) after adjusting for differences in age, race, comorbidity, cancer site, and extent of disease. There was a small but statistically significant decrease in chance of survival in blacks compared with whites (adjusted relative survival 0.96, 95% CI = 0.92–0.99). Conclusions Recent non-VA studies have shown stable survival for colorectal cancer patients over time, coupled with significantly decreased survival for blacks compared with whites. In contrast, in the VA system, survival has improved for both white and black patients; in addition, the racial discrepancy in survival is markedly attenuated. These results suggest that the benefits of prevention and treatment advances may be more readily achieved in the VA’s equal access, integrated health care system.