[Clinical characteristics and risk profile of individuals referred to familial breast cancer clinic of Tehran: the necessity of genetic counselling]

ABSTRACT

Genetic counseling represents the main basis of breast cancer risk assessment. During consultation, the major risk factors of breast cancer, the probability of developing breast cancer and prior probability of germ line mutation in predisposing genes are evaluated. In this study, we assessed the clinical characteristics and risk profile of breast cancer in patients referred to familial breast cancer clinic at Tehran. This study was conducted as a cross sectional research on patients with the positive family history of breast cancer in at least one of their first or second degree relatives who referred to familial breast cancer clinic. During the consultation in familial breast cancer clinic, the pedigree was drawn at least in 3 generations and the history of the breast, ovary and other cancers in the family was assessed. Breast cancer risk factors were evaluated according to the Gail and Claus models and the probability of germ line mutation in BRCA1/2 genes was estimated using the BRCAPRO model. Data analysis was performed by SPSS 13. During the study period, 220 individuals from 45 families were evaluated. At the time of genetic conselling, 84 patients [38.2%] were affected by breast cancer and 6 patients by ovarian cancer. The mean number of breast cancer patients in each family was 1.87. In 14 patients breast cancer occured bilaterally. There was not any history of male breast cancer in the studied families. The average risk of developing breast cancer for breast cancer unaffected individuals was estimated at 17.84% and 19.12% according to the Claus and Gail models respectively. According to BRCAPRO model, the average prior probability of germ line mutation in BRCA1/2 genes was 13.74%. About 1/3 of study population had mutation probability of greater than 10%.The results of this study showed that in the majority of the consulted individuals the family history of breast, ovarian and other cancers was positive and in the most families, the risk factors for hereditary breast cancer were observed. According to mutation probability of 10%, genetic testing was indicated in 62 [32%] individuals. This represents the necessity of paying more attention to susceptible individuals for hereditary breast cancer and providing the facilities of genetic testing for them. It seems necessary to conduct more studies in order to determine the role of germ line mutation in BRCA1/2 genes at developing breast cancer in Iranian population