Risk factors for endometrial cancer among black South African women: a case control study

MSc (Med), Biostatistics and Epidemiology, Faculty of Health Sciences, University of the Witwatersrand, 2009Introduction: Endometrial cancer is a gynaecological cancer that mostly affects women in their sixth and seventh decades of life. It is the fourth most common malignancy in women and ranks eighth among all causes of female cancer in terms of age-adjusted mortality. In developed and numerous developing countries endometrial cancer, as well as other types of cancer in women, is an ever-increasing threat that may be explained, among other reasons, by increased life expectancy and a reduction in fertility or birth rates. Conversely, in South Africa and most other African countries, the previous reasons do not exist, because there is a decline in life expectancy due to increased HIV, low income, and a high fertility rate. International epidemiological studies have established significant relationships between endometrial cancer and risk factors such as the woman’s age, race, early menarche and late menopause, parity, a history of breast or ovarian cancer, the use of endogenous estrogens, concomitant diabetes, family history of breast and ovarian cancer, estrogen therapy, obesity, and the use of tamoxifen. The aim of the study was to identify risk factors associated with endometrial cancer among black South African women. Method: The present case control study comprised black South African women diagnosed with a cancer in Johannesburg, between 1995 and 2005. The study included 592 women aged 27 to 90 years who were admitted to three main public hospitals in the city of Johannesburg with histologically confirmed cancers. 148 cases with endometrial cancer and 444 women with other forms of cancer were analysed. Only newly occurring cases (incident) were included. Women in the control group consisted of those with V cancers not associated with reproductive or hormonal factors, i.e. not cancers of the breast or the female reproductive system. Data handling, cleaning and analysis were done using Stata 9 (STATA). Results: Univariate analysis showed that the risk for endometrial cancer was significantly (P<0.05) affected by: miscarriages, the place of former residence, place of current residence, the use of snuff, wine consumption, age of the youngest child, diabetes, age of menarche, age of menopause, and menstrual status. Smoking was found to be a protective factor for endometrial cancer compared to other cancers. After multivariate adjustment, endometrial cancer risk was significantly (P