Oral contraceptive and breast cancer risks: A case control study in six referral hospitals in Indonesia

Objective: This study aimed to understand the effects of the use of oral contraceptive to breast cancer risk in six referral hospitals in Indonesia. Methods: The research design was hospital based case-control, conducted in 2013. Population was women patients aged 15 years and above in six cancer-referral hospitals in five provinces. Total of 762 people were included in this study consisting of 381 who are diagnosed with breast cancer as confirmed by histopathologic examination in inpatient surgery ward, and 381 people who are not diagnosed with breast cancer based on interview in outpatient surgery ward as control group. A set of data were collected including the use of oral contraceptives, age, early menarche, childbirth status, breastfeeding status, obesity, unhealthy diet, history of benign breast tumors, family history of breast cancer, and age of menopause. Result: Results showed that Odds Ratio (OR) of patients using oral contraceptive < 6 years was 1.93 (95% CI 1.23 - 3.03) and OR of those using oral contraceptive = 6 years was 2.90 (95% CI 1.65- 5.09) as compared to people who did not use oral contraceptive. Conclusion: Use of oral contraceptive in patients was indicated to increase the risk of breast cancer. Longer the duration of using oral contraceptive tend to have higher the risk of breast cancer.