Nutrition, Lifestyle, and Breast Cancer Risk Among Turkish Women Esin Ceber, Neriman Sogukpinar, Gulengul Mermer, and Gulsun Aydemir Abstract: Breast cancer is the most common malignancy in women, with more than 1 million cases occurring worldwide annually. Cancer is one of the leading causes of mortality in Turkey; deaths due to breast cancer constitute 24.1% of all carcinoma cases reported among women. We conducted a case-control study of Turkish women with and without breast cancer to investigate the relationships of selected lifestyle and nutritional risk factors with breast cancer risk. Factors were chosen based upon published associations with breast cancer. Subjects were women in Izmir, Turkey. Cases were 123 women with breast cancer registered with the Depart- ment of Oncology, Ege University Hospital, in February through July 2004. The control group included 120 randomly selected women without a breast cancer diagnosis, registered with the Evka-4 Health Care Center and having similar sociodemographic characteristics. Inclusion criteria for participation consisted of 40 yr of age and over and willing- ness to participate. ? 2 tests and t-tests were used to determine statistical differences between cases and controls based on selected variables. Logistic regression was used to find the association between selected risk factors and breast cancer occurrence. Cases had smoked for more years, their age of first pregnancy was higher, and breast cancer occurrence was more common in first-degree relatives such as mothers and sisters of cases compared with controls. Cases were found to have consumed higher amounts of vegetable oil in contrast to controls. These findings are consistent with simi- lar studies conducted in both developed and developing countries. Introduction One of the important public health problems affecting women’s health is breast cancer. Breast cancer is the most common malignancy in women, with more than 1 million cases occurring worldwide annually (1). Although breast cancer incidence is relatively low (42.7 per 100.000) in Tur- key when compared with developed Western countries such as England and the United States (91.6 per 100.000), breast cancer has been a health problem for women in our country in recent years. Cancer is one of the leading causes of mortal- ity in Turkey; deaths due to breast cancer constitute 24.1% of all carcinoma deaths reported among women (2,3). The incidence of breast cancer varies greatly from one population to another, depending on the prevalent risk fac- tors (1,4). Various factors, including geographical, socio- demographic, obstetric, lifestyle, and nutritional, may play a role in the etiology of breast cancer (5–8). These factors are well established in many reviews in developed countries (9–11). Turkey is a developing country in the middle of Europe and Asia with a population of 67.8 million and a fertility rate of 2.61 per year. Sixty-five percent of the total population is aged between 15 and 64 yr (12). In developing countries such as Turkey, the lifestyle of populations is changing due to in- ternal migration, education, and Westernization. Since the beginning of the 20th century, Turkey has been in a sociodemographic, cultural, and economic transformation. This transformation caused some changes related to lifestyle, such as the increase in the habit of smoking, an increase in the age of marriage and first pregnancy, a decrease in the du- ration of breastfeeding, and changes in dietary habits. How- ever, women living in both rural and urban areas in Turkey still take little physical exercise, usually consume fresh vege- tables and fruit, and have a higher number of pregnancies in comparison with women in developed countries. Although Kuru et al. (13) and Oran et al. (14) carried out some studies that evaluate the lifestyle factors related to breast cancer risk, those studies have received little attention in Turkey. To our knowledge this is the first study that evaluates the association between lifestyle, obstetric, and nutritional factors and breast cancer conducted in the western Turkey. Objective The objective of this study was to examine the associa- tions between selected lifestyle and nutritional risk factors and breast cancer risk among women diagnosed with breast cancer and health controls living in Izmir, Turkey. NUTRITION AND CANCER, 53(2), 152–159 Copyright © 2005, Lawrence Erlbaum Associates, Inc. All authors are affiliated with the Ege University Izmir Ataturk School of Health, Izmir, Turkey.