Breast cancer patterns and lifetime risk of developing breast cancer among Puerto Rican females.

OBJECTIVES: The purpose of this study was to evaluate the epidemiologic patterns of breast cancer and to estimate the lifetime risk probability of developing breast cancer among Hispanic females using cancer data from Puerto Rico.

BACKGROUND: The age-adjusted breast cancer incidence rate (per 100,000) in Puerto Rico increased from 15.3 in 1960-1964 to 43.3 in 1985-1989. The age-adjusted breast cancer mortality rate (per 100,000) increased from 5.7 to 10.6 comparing the same two time periods (1960-1964 vs 1985-1989). Nevertheless, in 1985-1989 breast cancer incidence rate was higher in US White females (110.8 per 100,000) compared to Puerto Rican females (51.4 per 100,000; age-adjusted to the 1970 US standard population). The breast cancer mortality rate was also higher in US White females (27.4 per 100,000) than in Puerto Rican females (15.1 per 100,000; age-adjusted to the 1970 US standard population) during 1985-1989.

METHODS: A multiple decrement life table was constructed applying age-specific incidence and mortality rates from cross-sectional data sets (1980-1984 and 1985-1989 data for Puerto Rican females and 1987-1989 SEER data sets for US White and Black females) to a hypothetical cohort of 10,000,000 women. The probability of developing invasive breast cancer was computed for the three groups using the long version of DEVCAN: Probability of DEVeloping CANcer software, version 3.3.

RESULTS: The lifetime risk of developing breast cancer was 5.4% for Puerto Rican females, compared to 8.8% for US Black females and 13.0% for US White females. Lifetime risk for Puerto Rican females increased from 4.5% in 1980-1984 to 5.4% in 1985-1989.

CONCLUSIONS: Lifetime risk of breast cancer appears to be increasing in Puerto Rico, but remains lower than the probability for US White females. Therefore, the application of lifetime probability of developing invasive breast cancer estimated for the US female population will overestimate the risk for the Puerto Rican female population.