Association of Increasing Age-Specific Breast Cancer Incidence Rates with Drinking Habits but Not Obesity Prevalence, Based on National Data in Japan

Abstract

Background and Objective: Breast cancer incidence rates are increasing in East and Southeast Asia due to the westernization of lifestyle. This study aimed to assess the association of age-specific breast cancer incidence rates with drinking habits and obesity among Japanese women. Materials and Methods: Data on age-specific cancer incidence rates, drinking habits and prevalence of obesity were obtained from the open data published by Cancer Information Services or National Institute of Health and Nutrition, Japan. Linear associations between the age-specific cancer incidence rates, drinking habits (alcohol, 20 g and over 3 times or more a week) and prevalence of obesity (body mass index, 25 and over) were assessed by Pearson’s correlation coefficient. Results: The age-specific incidence rates of breast cancer in 5-year age groups increased during the 10 years (from 2005 to 2015) in a bimodal pattern; cancer of corpus uteri increased in a bell-shaped pattern; and colon cancer increased with age in a similar pattern. Drinking habits were significantly correlated with the increasing incidence rates of three types of cancer (breast, corpus uteri and colon cancers), especially with breast cancer at the age of 50-79 years. No positive correlations were observed between these three types of cancer and prevalence of obesity. Conclusion: The present study indicated that westernized drinking-related lifestyle among Japanese women is associated with a higher rate of age-specific breast cancer incidence. Counseling program on lifestyle modification can be beneficial for women.