Breast cancer risk factor evaluation in a Western Himalayan state: A case-control study and comparison with the Western World

Context: Breast cancer incidence is increasing rapidly in India. The lifestyle, built, genetic makeup, reproductive and breastfeeding patterns are quite different in Indian females when compared to the Western population. Generalizing the Western data to the population residing in the Himalayan region would breed inaccuracies. Aim: The aim of our study was to identify risk factors in our own population in a Western Himalayan state of Himachal Pradesh, India. Subjects and Methods: A case-control study with 377 cases of invasive breast cancer and 346 hospital-based controls was conducted for 1 year. The data were collected by interviewing the individuals during their visit to hospital using a questionnaire. The data were analyzed using standard statistical techniques using SPSS version 17 software. Results: Factors found to have strong association with invasive breast cancer on multivariate analysis are late age at first childbirth >30 years, which is the strongest risk factor associated, late age of menopause > 50 years, high socioeconomic class, and age of female above 50 years. Conclusion: In our females, age >50 years, late age of menopause (>50 years), late age at first childbirth (>30 years), and high socioeconomic status were found to be major risk factors associated with breast cancer. Several factors implicated in the Western data were not found to be significant in our study. We need to identify such aspects in reproductive and breastfeeding patterns of women and spread awareness regarding the same.