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[Problems raised by the gynaecologic management of women with BRCA 1 & 2 mutations].

Breast and ovarian cancer occur more frequently in young women with BRCA 1 &2 mutations (respective cumulative risks from 37 to 85% and 10 to 20%), and raise specific gynaecologic problems as prophylactic surgery and hormonal treatments. Two medical files from 2 sisters with BRCA 1 mutation (exon 11) are presented and the authors discuss the therapeutic options chosen. BRCA 1 & 2 tumour suppressor genes seem to play a major role in the repair of cellular damages inducing by the estrogenic proliferative signal. The prophylactic mastectomy is effective for the breast cancer prevention but its acceptance is low. The oophorectomydecreases the ovarian risk (knowing the occurrence of peritoneal carcinomatosis in 1.8% of cases) and currently the breast cancer risk (RR = 0.47) by the hormonal privation: the hormone replacement therapy does not seem to increase the breast cancer risk in the small series published. The HRT is possible in women with BRCA mutation under medical supervision and if the doses of hormones are light. The first results concerning the chemoprevention by Tamoxifen are encouraging (RR = 0.38) in these patients, but more studies are needed. The oral contraception exerts an uncertain effect against ovarian cancer, but possibly enhances the breast cancer risk in this group of women (RR = 3.3). The management of women with BRCA mutation is varying according to their own priorities, which can change during their life.

Adolescent↗

Germ-line mutations in BRCA1 or BRCA2 in the normal breast are associated with altered expression of estrogen-responsive proteins and the predominance of progesterone receptor A.

The breast cancer susceptibility genes BRCA1 and BRCA2 are responsible for a large proportion of familial breast and ovarian cancer, yet little is known of how disruptions in the functions of the proteins these genes encode increased cancer risk preferentially in hormone-dependent tissue. There is no information on whether a germ-line mutation in BRCA1 or BRCA2 causes disruptions in hormone-signaling pathways in the normal breast. In this study markers of hormone responsiveness were measured in prophylactically removed normal breast tissue (n = 31) in women bearing a germ-line pathogenic mutation in one of the BRCA genes. The estrogen receptor (ER) and proteins associated with ER action in hormone-sensitive tissues, namely, PS2 and the progesterone receptor (PR), were detected immunohistochemically. ER expression was not different in BRCA mutation carriers than in noncarriers, but there was a reduction in PS2 expression. PR expression was also reduced, and there was a striking lack of expression of the PRB isoform, which resulted in cases with PRA-only expression in BRCA1 and BRCA2 mutation carriers. The alterations in PS2 and PR expression were similar in the BRCA1 and BRCA2 carriers, demonstrating that although these proteins are structurally and functionally distinct, there is overlap in their interaction with hormone-signaling pathways. This study provides evidence for altered cell function arising from loss of function of one BRCA allele in the normal breast, leading to PS2 loss, preferential PRB loss, and expression of PRA alone. In breast cancer development, PRA overexpression becomes evident in premalignant lesions and is associated with features of poor prognosis in invasive disease and altered cell function in vitro. The results of this study suggest that heterozygosity for a germ-line mutation in BRCA1 or BRCA2 results in development of PRA predominance. This is likely to lead to changes in progesterone signaling in hormone-dependent tissues, which may be a factor in the increased risk of cancer in these tissues in women with germ-line BRCA1 or BRCA2 mutations.

Adult↗

Hereditary breast and ovarian cancer in Asia: genetic epidemiology of BRCA1 and BRCA2.

Ethnic differences in cancer incidence and mortality result from differences in genetic and epidemiologic risk factors. Mutations in BRCA1 and BRCA2 account for a small proportion of all breast cancer cases, but for a much higher proportion of cases with a strong family history of breast or ovarian cancer. Germline mutations in BRCA1 and BRCA2 have been identified in individuals of many races and ethnic groups and the frequency of mutations varies between these groups. Some of the differences in cancer risk between populations may be the result of founder mutations in these genes. The cost and time required for mutation analysis are reduced considerably when founder mutations are identified for a specific ethnic group. The BRCA2 999del5 mutation in Iceland and three BRCA mutations in Ashkenazi Jews are well characterized. However, considerably less is known about the contribution of mutations in the BRCA1 and BRCA2 genes outside of European groups. Studies conducted on the Asian populations described here have expanded our current knowledge of genetic susceptibility and its contribution to breast and ovarian cancer rates in Asian populations.

Asia↗

BRCA1 1675delA and 1135insA account for one third of Norwegian familial breast-ovarian cancer and are associated with later disease onset than less frequent mutations.

A total of 845 women from breast-ovarian cancer kindreds were enrolled in a clinical follow-up program for early disease diagnosis; 35 women were prospectively identified with cancer. In order to estimate the role of genetic factors for cancer predisposition in this well-defined set of patients, considered as representative for familial breast-ovarian cancer in the Norwegian population, the BRCA1 gene was investigated for germline mutations. The entire coding region of BRCA1 was analysed using a protein truncation test, direct sequencing and a screen for known large genomic deletions and insertions. Twenty one (60%) of the 35 patients were identified as carriers of 11 distinct BRCA1 mutations. Two previously described founder mutations, 1675delA and 1135insA, were found to account for more than half (11/21) of all BRCA1 cases and for almost one third (11/35) of all breast and ovarian cancers. Supported by a previous population-based analysis of these founder mutations in ovarian cancer, our findings suggest that a significant proportion of women at risk for developing inherited breast and ovarian cancer can be identified. This is particularly obvious in certain geographic regions where these founder mutations are prevalent. Women carrying the two founder mutations had a significantly older age of disease onset as compared to women with other BRCA1 mutations. This observation indicates that BRCA mutation penetrance estimates from populations with strong founder effects may be biased. One reason why some deleterious mutations are allowed to prevail in a population may be coupled to penetrance and the fact that they seldom induce disease in women in child-bearing ages. Eleven out of 12 (92%) breast cancers in BRCA1 mutation carriers were estrogen receptor negative, versus 4 out of 9 (44%) in mutation negative patients (p = 0.03). Histopathological characteristics of the prospectively detected cancers indicated an unfavourable prognosis in mutation carriers.

Adult↗

A candidate precursor to serous carcinoma that originates in the distal fallopian tube.

The tubal fimbria is a common site of origin for early (tubal intraepithelial carcinoma or TIC) serous carcinomas in women with familial BRCA1 or 2 mutations (BRCA+). Somatic p53 tumour suppressor gene mutations in these tumours suggest a pathogenesis involving DNA damage, p53 mutation, and progressive loss of cell cycle control. We recently identified foci of strong p53 immunostaining-termed 'p53 signatures'-in benign tubal mucosa from BRCA+ women. To examine the relationship between p53 signatures and TIC, we compared location (fimbria vs ampulla), cell type (ciliated vs secretory), evidence of DNA damage, and p53 mutation status between the two entities. p53 signatures were equally common in non-neoplastic tubes from BRCA+ women and controls, but more frequently present (53%) and multifocal (67%) in fallopian tubes also containing TIC. Like prior studies of TIC, p53 signatures predominated in the fimbriae (80-100%) and targeted secretory cells (HMFG2 + /p73-), with evidence of DNA damage by co-localization of gamma-H2AX. Laser-capture microdissected and polymerase chain reaction-amplified DNA revealed reproducible p53 mutations in eight of 14 fully-analysed p53 signatures and all of the 12 TICs; TICs and their associated ovarian carcinomas shared identical mutations. In one case, a contiguous p53 signature and TIC shared the same mutation. Morphological intermediates between the two, with p53 mutations and moderate proliferative activity, were also seen. This is the first report of an early and distinct alteration in non-neoplastic upper genital tract mucosa that fulfils many requirements for a precursor to pelvic serous cancer. The p53 signature and its malignant counterpart (TIC) underline the significance of the fimbria, both as a candidate site for serous carcinogenesis and as a target for future research on the early detection and prevention of this disease.

Biomarkers, Tumor↗

BRCA1 and BRCA2 mutations in Turkish breast/ovarian families and young breast cancer patients.

To date, BRCA1 and BRCA2 mutations in breast and/or ovarian patients have not been characterized in the Turkish population. We investigated the presence of BRCA mutations in 53 individuals with a personal and family history of breast and/or ovarian cancer, and 52 individuals with a personal history of breast cancer diagnosed below age 50 without additional family history. We have identified 11 mutations (nine BRCA1 and two BRCA2) using combined techniques involving protein truncation test, direct sequencing and heteroduplex analysis. We found eight out of 53 patients (15.1%) with a family history to carry BRCA gene mutations (seven BRCA1 and one BRCA2). Of these, four were found in 43 families presenting only breast cancer histories, and four were found in families presenting ovarian cancer with or without breast cancer. We also demonstrated two BRCA1 and one BRCA2 mutations in three out of 52 (5.8%) early-onset breast cancer cases without additional family history. Three of nine BRCA1 and both BRCA2 mutations detected in this study were not reported previously. These mutations may be specific to the Turkish population. The BRCA1 5382insC mutation, specific to Ashkenazi and Russian populations, was found twice in our study group, representing a possible founder mutation in the Turkish population.

Adult↗

Improved survival in women with BRCA-associated ovarian carcinoma.

BACKGROUND: The objective of this study was to determine the clinical characteristics, treatment response, and frequency of p53 overexpression in Ashkenazi Jewish women with hereditary ovarian carcinoma. METHODS: Seventy-one Jewish women with epithelial ovarian carcinoma (EOC) were tested for the three BRCA founder mutations using single-strand conformation polymorphism analysis, heteroduplex analysis, and protein truncation testing. Clinical and histopathologic data were reviewed retrospectively. In vitro chemoresistance was analyzed in 32 patients. Mutations of p53 were studied using immunohistochemical detection of p53 overexpression. RESULTS: Thirty-four of 71 Jewish patients with EOC (48%) had germline BRCA mutations (BRCA heterozygotes), including 22 BRCA1 mutations and 12 BRCA2 mutations. BRCA heterozygotes were younger compared with Jewish patients who had EOC without mutations (sporadic carcinoma; 50 years vs. 59 years, respectively; P = 0.01). BRCA1 heterozygotes were younger compared with BRCA2 heterozygotes (48 years vs. 57 years, respectively; P = 0.01). Histopathologic tumor features were similar; however, tumors with low malignant potential were seen only in women with sporadic carcinoma. Both groups had equivalent rates of surgical cytoreduction and similar median follow-up (72 months). BRCA heterozygotes had higher response rates to primary therapy compared with patients who had sporadic disease (P = 0.01). In vitro chemoresistance predicted tumor response to platinum chemotherapy correctly in BRCA heterozygotes (P = 0.0096). BRCA heterozygotes with advance-stage disease had improved survival compared with patients who had advanced stage sporadic carcinoma (91 months vs. 54 months, respectively; P = 0.046) and had a longer disease free interval (49 months vs. 19 months, respectively; P = 0.16). p53 overexpression was common in BRCA heterozygotes (80%). CONCLUSIONS: BRCA1 heterozygotes developed EOC at a younger age compared with BRCA2 heterozygotes and women who had sporadic ovarian carcinoma. BRCA heterozygotes had a better response to platinum chemotherapy compared with women who had sporadic disease, which may have contributed to their improved prognosis.

Adult↗

Optimal selection for BRCA1 and BRCA2 mutation testing using a combination of 'easy to apply' probability models.

To establish an efficient, reliable and easy to apply risk assessment tool to select families with breast and/or ovarian cancer patients for BRCA mutation testing, using available probability models. In a retrospective study of 263 families with breast and/or ovarian cancer patients, the utility of the Frank (Myriad), Gilpin (family history assessment tool) and Evans (Manchester) model was analysed, to select 49 BRCA mutation-positive families. For various cutoff levels and combinations, the sensitivity and specificity were calculated and compared. The best combinations were subsequently validated in additional sets of families. Comparable sensitivity and specificity were obtained with the Gilpin and Evans models. They appeared to be complementary to the Frank model. To obtain an optimal sensitivity, five 'additional criteria' were introduced that are specific for the selection of small or uninformative families. The optimal selection is made by the combination 'Frank >or=16% or Evans2 >or=12 or one of five additional criteria'. The efficiency of the selection of families for mutation testing of BRCA1 and BRCA2 can be optimised by using a combination of available easy to apply risk assessment models.

Adult↗

Distinction between hereditary and sporadic breast cancer on the basis of clinicopathological data.

BACKGROUND: About 5% of all breast cancer cases are attributable to germline mutations in BRCA1 or BRCA2 genes. BRCA mutations in suspected carriers, however, may be missed, which hampers genetic counselling. MATERIALS AND METHODS: Different clinicopathological features were compared between 22 breast cancers from carriers of proved BRCA1 mutations and 604 cancers from sporadic controls. In addition, 5 BRCA2-related breast cancers and 66 breast cancers of untested patients at intermediate risk and 19 breast cancers of untested patients at high risk of hereditary disease on the basis of family history were evaluated. RESULTS: A "probably sporadic" class (age >or=54 years and epidermal growth factor receptor (EGFR) negative; 68% of cases) with a 0% chance of BRCA1-related breast cancer containing 79% of the sporadic cases was yielded by using a decision tree with age, Ki67 and EGFR. A 75% chance of BRCA1-related breast cancer was shown by the "probably BRCA1-related" class (age <54 years and Ki67 >or=25%; 8% of cases) with 82% of the BRCA1-related cases but only 1.4% of the sporadic cases. Most cases at intermediate or high risk of hereditary disease on the basis of family history could be classified with high probability as either probably BRCA1 related or probably sporadic. CONCLUSION: Breast carcinomas can be classified with a high level of certainty as sporadic or related to BRCA1 germline mutations by using a decision tree with age, Ki67 and EGFR. This can be clinically useful in mutation analysis in families with a borderline risk of hereditary disease.

Adult↗