AGE-PERIOD-COHORT ANALYSIS OF BREAST-CANCER MORTALITY

The objective of this study is to develop a hypothesis about the carci nogenesis of breast cancer for a descriptive analysis. This study is a n application of the age-period-cohort model (APC model) on the mortal ity rate of breast cancer in taiwan over the period from 1964 to 1991. Age-specific and age-adjusted mortality rates are described and then age, period, and cohort effects are separately analysed. (Female) brea st cancer mortality data in taiwan from 1964 to 1991 were abstracted f rom the annual reports of the Taiwan Provincial Department of Health. The population data in Taiwan from 1964 to 1991 were abstracted from t he demographic data in Taiwan compiled by the Ministry of Interior, R. O.C. The results show that both age-adjusted and age-specific mortalit y rates of breast cancer are increasing over the study period and with birth cohorts. The bimodal pattern becomes more apparent in later per iods. The Clemmensen's hook in five years later both in the descriptiv e study and the APC analysis. The findings suggest a possible role of later life overnutrition as the major period effed (prompter) and a ch ange in reproductive behavior as the cohort effect (initiator). The ap plication of the APC model also denotes the possible roles of later li fe overnutrition and a change in reproductive behavior after the birth cohort of 1929. These findings may help us develop hypotheses of carc inogenesis of breast cancer.