ABSTRACT
RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) have recently been involved in breast and ovarian cancer predisposition: RAD51B, RAD51C, and RAD51D in ovarian cancer, RAD51B and XRCC2 in breast cancer. The aim of this study was to estimate the contribution of deleterious variants in the five RAD51 paralogs to breast and ovarian cancers. The five RAD51 paralog genes were analyzed by next-generation sequencing technologies in germline DNA from 2649 consecutive patients diagnosed with breast and/or ovarian cancer. Twenty-one different deleterious variants were identified in the RAD51 paralogs in 30 patients: RAD51B (n = 4), RAD51C (n = 12), RAD51D (n = 7), XRCC2 (n = 2), and XRCC3 (n = 5). The overall deleterious variant rate was 1.13% (95% confidence interval (CI): 0.72-1.55%) (30/2649), including 15 variants in breast cancer only cases (15/2063; 0.73% (95% CI: 0.34-1.11%)) and 15 variants in cases with at least one ovarian cancer (15/570; 2.63% (95% CI: 1.24-4.02%)). This study is the first evaluation of the five RAD51 paralogs in breast and ovarian cancer predisposition and it demonstrates that deleterious variants can be present in breast cancer only cases. Moreover, this is the first time that XRCC3 deleterious variants have been identified in breast and ovarian cancer cases.
Subject(s)
Breast Neoplasms/genetics , Ovarian Neoplasms/genetics , Rad51 Recombinase/genetics , Adult , Aged , Breast Neoplasms/pathology , DNA-Binding Proteins/genetics , Female , Germ-Line Mutation , Humans , Middle Aged , Ovarian Neoplasms/pathologyABSTRACT
In France, endometrial cancer is at the first rank of gynecological cancers for cancer incidence, before ovarian and cervical cancers. In fact, the number of incident cases has been estimated to 7275 for the year 2012; the number of death due to endometrial cancer to 2025. This cancer is hormone-dependent and endogenous (reproductive factors) or exogenous (oral combined contraceptives, hormone replacement therapy) causes of exposition to estrogens are the major environmental risk factors for both types of endometrial cancers: type I or well-differentiated endometrioid adenocarcinomas; and type II including all other histological types: papillary serous adenocarcinomas, clear cell adenocarcinomas and carcinosarcomas, also known as malignant mixed Mullerian tumor, MMMT. Obesity, diabetes mellitus and adjuvant treatment of breast cancer with tamoxifen are also associated with an increased risk of endometrial cancer. Genetic factors may also be implicated in the pathogenesis of endometrial cancer either as "minor genetic factors" (susceptibility factors), which remain largely unknown and are responsible for the increased observed risk in relatives of women affected with endometrial cancer; or as major genetic factors responsible for hereditary forms and namely for Lynch syndrome whose genetic transmission is of autosomic dominant type. The appropriate recognition of Lynch syndrome is of critical importance because affected patients and their relatives should benefit from specific care. The aims of this review is to describe major environmental and genetic risk factors for endometrial cancer with specific attention to most recent advances in this field and to describe recommendations for care of at-risk women.
