BREAST CANCER RISK FACTORS IN AN URBAN AREA OF YAZD CITY- IRAN, 2006
Breast cancer is the most common malignancy in women in many parts of the world. The risk factors for breast cancer cover a broad range of conditions, from age to complex genetic alterations. Present data is showing an increase in the annual incidence rates of disease and it is ranked as the first recorded malignancies among Iranian women after 1999. To study the association of reproductive and non reproductive factors with breast cancer among women with age group 30-75 years residing in urban area of Yazd city, Iran, this community based case-control study was carried out. A total of 160 subjects including 80 cases and 80 community controls were studied. Age was matched for both the case and control groups. Association of various kinds of risk factors with breast cancer was studied using odds ratios with 95% confidence intervals through both the univariate and multivariate analysis. The findings based on multivariate analysis showed that being employment in outdoor jobs, positive familial history of breast cancer amongst the first grades, early onset of the first menstruation cycle (≤ 13 ys.), delayed age of the first marriage (≥ 19 ys.), less number of live children (≤ 3) and less duration of breastfeeding (≤ 2 ys.) were significantly associated with breast cancer. However, consumption of OCPs was found to be a protective factor for breast cancer. Our study showed that the role of reproductive factors in the causation of breast cancer was more important than in other factors like socio-economic, psychological, behavior and nutritional factors.