Predictors of breast cancer among women in a northern state of Malaysia: a matched case-control study.

Background: Breast cancer has been increased in South East Asia countries, but there are limited data for breast cancer risk factors in these countries. To clarify the risk for breast cancer among the Malaysian women, a matched case-control study was conducted.

Method: Between October 2009 and April 2010, a survey was prospectively conducted among women admitted to clinics of Penang General Hospital for examination and/or treatment by using a questionnaire. Therefore, characteristics of patients diagnosed with breast cancer (n=150) were compared with control cases (n=150) admitted to hospital for non-neoplastic, non-hormone related diseases.

Results: Family history of a distant relative with breast cancer (OR=2.84), history of first-degree relatives with breast cancer (OR=2.95), history of benign breast disease (OR=2.43), menstrual irregularity (OR=4.24), and use of oral contraceptive pills (OCP) (OR=2.15) were found to be significant risk factors for breast cancer in our population. Furthermore, education more than 11 years (OR=0.40), breastfeeding (OR=0.50), being employed (OR=0.45) and practicing low fat diet (OR=0.53) were strongly protective against breast cancer development.

Conclusion: The results emphasize the importance of conducting a series of awareness campaigns that highlights the protective role of longer breastfeeding period against breast cancer and the negative relationships between OCP use and high fat diet with this disease.