Distribution of breast cancer risk factors in two groups of healthy people referral to cancer registry and Shahid Mottahari center.

The aim of this study is evaluation of breast cancer risk factors distribution in two groups of healthy people referral to cancer registry and Shahid Mottahari center in Iran. This study is cross-sectional study which is part of the study to estimate Gene-Environment Interaction in women with breast cancer with case-control studies in Shiraz. In this study, two control groups have been used. The sample size of 300 was specified for each group. Selection sources of groups include Cancer Registry Center and referred people to surgical and internal ward of Shahid Mottahari Clinic. Information collect tools have included Form No. 1 in Cancer Registry Center which includes information of age, use of oral contraceptives history, breastfeeding history, number of live births, age at menarche, age at first childbirth, etc. Considering the results obtained, it was showed that the highest frequency (144) in the group of Cancer Registry Center belongs to high school education, but the highest frequency of Shahid Mottahari Clinic is related to primary education (176).There is statistically significant difference between the two groups in terms of education, history of breast cancer in first-degree relatives and age at first birth, ( P <0.05). Due to the easy availability of data on non-cancer patients referred to the cancer registry center, researchers may be encouraged to use them as a control group, but we must bear in mind that, this Group may be different in terms of some variables, and this difference leads to bias in the estimation of considered exposure effects.