Risk Factors for Breast Cancer among Women in Klang Valley, Malaysia

There has been an explosion in the incidence of breast cancer throughout the world. A casecontrol study was done to identify the lifestyle risk factors for breast cancer among women in Klang Valley. This study was carried out among 70 newly diagnosed breast cancer patients and 138 controls, aged 29-65 years old in Klang Valley. The inclusion criteria for cases were (i) newly diagnosed breast cancer (stage I to III) (ii) not undergone any therapy for cancer (iii) no other chronic diseases such as hypertension and diabetic (iv) not pregnant and lactating (v) not in menstruation for those who are not menopause yet. The control group comprised women, who were healthy, not diagnosed with cancer and other chronic disease, not pregnant, not lactating and not menstruating. Demographic data were obtained through standardized pre-tested questionnaire by trained interviewers. Smoking, alcohol consumption, family history, age at menarche, usage of oral contraceptive pill and hormone-replacement therapy, breast-feeding, chi-square test did not show any significant differences between cases and control. Women who got her first pregnancy at the age of more than 30 years old were at five time higher risk of getting breast cancer [adjusted OR=4.5 (95% CI=1.8-11.1)] (p<0.05) compared to those who got her first pregnancy at the age less than 30 years old. In conclusion, certain lifestyle factors were associated with risk of getting breast cancer. Effort should be taken to increase awareness and understanding of the importance of healthy lifestyle to prevent breast cancer occurrence.