Association between mammographic breast density and breast carcinoma.

Introduction: Breast cancer has a high incidence and is showing a rising trend in Sri Lanka. Mammographic breast density is a radiologically measurable risk factor which has been found to be significantly associated with breast cancer risk in women with minor variations between ethnicities. However, the Asian populations studied in previous international studies were of Japanese, Chinese and Filipino ethnicities and not Sri Lankan or other South Asian ethnicities. Also, a previous Sri Lankan study found no significant association between breast density and breast cancer. Therefore it is of interest to study whether there is actually an association between breast density and breast cancer in Sri Lankan women.

Objectives: This study aimed to assess whether there is a significant association between mammographic breast density and breast cancer in a Sri Lankan women and also to assess factors affecting breast density.

Methodology: We conducted a retrospective unmatched case control study of 110 women (22 cases of breast cancer and 88 controls) aged between 40 and 75 years who came for mammography to Sri Jayewardenepura General Hospital. Breast density was categorized in to two, as lower density (BIRADS type a and b compositions) and higher density (type c and d compositions) for the analysis.

Results: Contrary to most international research findings and similar to the previous Sri Lankan study, no significant association was found between breast density and breast cancer. Additionally, out of multiple factors, only age, menopausal state and BMI were found to be significantly associated with breast density. Conclusion :These findings may indicate that there is a true difference in the Sri Lankan population form the previously studied international populations suggesting that there is no association between breast density and breast cancer in Sri Lankan women. A further multicenter research is necessary to prove or disprove this theory.