부산대학교 도서관

Breast cancer is the fifth cause of cancer death worldwide and the second one in developed countries. The knowledge of the risk factors predisposing to suffer it , allows to develop a suitable primary and secondary prevention, in order to disminish the incidente of BC in the first case and establish an early diagnosis in the second one. Between 5-10% of BC are hereditary, mainly by BRCA1 and BRCA2 mutations causing the Hereditary Breast and Ovarian Cancer Syndrome. Women who carry these alterations have an increased BC risk than general population, with ranges between 55 and 85%. As well, they have a high risk of ovarian cancer estimated between 16 and 59% lifelong, and risk of developing other tumours as colon or pancreatic cancer. Also, several studies have evidenced that women who have suffered a BC and have a deleterious BRCA mutation present an increased risk of having contralateral BC, ranging between 30 and 40%. Among preventive strategies offered to these women we have contralateral prophylactic mastectomy and prophylactic bilateral salpingoophorectomy.However, after nearly two decades of research, it remains controversial which is the best local treatment we can offer to these women who have received breast conserving surgery and adjuvant radiotherapy (RT). Multiple studies have attempted to determine the rate of locorregional recurrence (RLR) in these patients, as well as the time to relapse.While some of them advocate to a greater risk of RLR in these women, others assume that is comparable to RLR in sporadic BC women. Currently, there is no agreement reached on the type of surgery to be performed in these patients. Given these findings, we raised a multicenter retrospective case-control observational study. We considered for this study 986 patients diagnosed with BC before January 2010 and who received breast-conserving surgery and RT.Among them, 173 patients were carriers of a pathogenic mutation in BRCA 1 / 2 after being studied in one of the five Genetic Counselling Cancer Unit in Valencia and 813 patients were women with sporadic BC treated at the Oncologic Valencian Institution. The main objective of the study was to analyze the rate of RLR and its characteristics in case´s group and to compare it to control study, as well as evaluate the follow-up of both populations in terms of relapse-free survival, locorregional relapse-free survival and overall survival. On one hand, a multivariated analysis has been conducted to isolate the effect of the mutation controlling the other factors. On the other hand, this study has been complemented by another one where individuals from the two study groups were matched one by one according clínical tumoral stage, clinical ganglionar stage and her2 status. The results of our study allow us to conclude that women with BC conserving-surgery and BRCA mutation have an increased risk of ipsilateral recurrence compared to women with sporadic BC who have received the same treatment (13,3% vs 3,3%, p=0,03). BC conserving-surgery and RT in women with BRCA 1 /2 mutation could not be the safer option to avoid locorregional relapse risk.