Abstract A83: Survival in Puerto Rican Hispanics, non-Hispanic whites, non-Hispanic blacks, and U.S. Hispanics with colorectal cancer: A five-year analysis

Abstract

Abstract Background: In Puerto Rico (PR), colorectal cancer (CRC) represents the second most common cause of cancer in men and women. Incidence and mortality of CRC are increasing in Puerto Rican Hispanics (PRH). Screening rates for CRC are lower in US and PR-Hispanics, which may result in advanced disease at diagnosis and poor outcomes. There is very limited data on survivorship among PR-Hispanic CRC patients. Hence, we compared the stage-specific five-year survival of Puerto Rican CRC patients with the stage-specific five-year survival of non-Hispanic Whites (NHW), non-Hispanic Blacks (NHB) and US Hispanics (USH) from mainland USA using SEER data during the 2001–2003 time period. Methods: All malignant CRC cases were obtained from the PR Central Cancer Registry (PRCCR), an island-wide population based cancer registry and the Surveillance, Epidemiology and End Results (SEER) Program, a multi-center cancer registry covering approximately 26 percent of the United States (US) population. CRC cases diagnosed from the years 2001 to 2003 were selected for the survival analysis. One-, three- and five-year relative survival were calculated using the incidence case file database of the PRCCR and the SEER and estimated using the Kaplan Meier method. Relative survival, defined as observed survival in the cohort divided by expected survival in the cohort, adjusted for the expected mortality from other causes of death were calculated. The 5-year survival functions were compared among demographics variables (sex, age group, racial/ethnic group and stage at diagnosis) via Z-tests. CRC reported in PR without stage and a sample of staged cases were examined and reviewed manually to ensure accuracy in the staging variable. Analyses were performed using SEER Stat 6.6.2. Results: Overall CRC incidence and mortality rates in PRH were 40.2 and 16.6; in NHW were 53.1 and 19.4; in NHB were 64.0 and 27.5; in USH were 39.4 and 13.8 per 100,000 population, respectively. A total of 3,359 PRH, 59,686 NHW, 7,700 NHB and 5,699 USH diagnosed with CRC during the 2001–2003 periods with complete survival data were evaluated. Overall CRC relative survival in PRH decreased within the 5-year observational period, with rates of 80.4%, 67.9%, and 62.9% for 1-, 3-, and 5-years, respectively. Overall CRC relative survival in NHW was 82.1%, 71.1% and 66.1%; in NHB was 75.7%, 61.0%, and 54.8% and in USH was 81.2%, 68.3%, and 62.1% each of them for 1-, 3-, and 5-years, respectively. Five-year stage-specific relative survival for localized, regional and distant CRC in PRH was 85.0%, 59.3% and 16.7%; in NHW was 91.4%, 69.4% and 10.1%; in NHB was 83.0%, 61.4% and 7.2% and in USH was 90.0%, 65.1% and 12.0%, respectively. Conclusions: Our study demonstrated low overall and stage-specific CRC 5-year relative survival for PR Hispanics, compared to previously reported data for US-Hispanics and non-Hispanic Whites. PR Hispanics with localized/regional CRC had lower 5-year relative survival rates than that observed in non-Hispanic Whites and US-Hispanics. The observed survival disparities in PR Hispanics with CRC warrant further studies evaluating the interplay of molecular, behavioral and/or environmental risk factors affecting this minority population. Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):A83.