Geographic variation of breast cancer in Taiwan: international and migrant comparison

Abstract

Background: Breast cancer is increasing rapidly in Taiwan. A geographic variation, international comparison and migrant study has become essential for the development of hypotheses to account for this.

Materials and methods: Age-adjusted mortality rates of breast cancer patients from all precincts and townships of Taiwan were calculated for a geographic variation study, and summarized for an international comparison. Age-specific and adjusted incidence rates of breast cancer in Taipei City were used for a migrant study.

Results: Age-adjusted mortality from breast cancer was highest in the Taipei and lowest in aboriginal areas. Oriental countries have significantly lower mortality rates from breast cancer but the incidence of breast cancer among Chinese women, and the difference between younger and older age groups has increased together with the degree of westernization in residential areas. Chinese women were found to have lower incidence rates than white women of the same area. We concluded that diet, reproductive behavior, and hereditary factors are involved in the development of breast cancer.