Regional differences of breast cancer risk factors in newly diagnosed female patients in Croatia

Sa？etak Background: Presence of breast cancer environmental risk factors may vary between the regions and settlement of residence size depending on the differences in lifestyle and level of specific exposures. Genetic risk factors could also show differences between regions. The aim of this cross-sectional study was to explore regional differences in breast cancer risk factors pertaining to the environment and genetics in medical history of newly diagnosed female patients in Croatia. Methods: We surveyed 203 women with newly diagnosed, previously untreated breast cancer (BCa) from all parts of Croatia, hospitalized consecutively between December 2016 and August 2017, for known BCa risk factors using the self-administered questionnaire. Data were analyzed separately by two main Croatian regions (continental, Mediterranean) and settlement of current residence size (urban, semi-urban/rural), as defined by Croatian Bureau of Statistics. Results: Women living in urban settlements were more often nulliparous or had their first child at an older age, had higher education level, lower number of children, more often consumed alcohol and were obese compared to those from semi-urban/rural areas. Women living in continental part of the country more often breast fed shorter. Several of the differences were also found between premenopausal and postmenopausal women. Conclusion: In total breast cancer population, we noticed several regional and urban BCa risk factor variations characteristical for lifestyle differences