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Background: Knowing a young woman with newly diagnosed breast cancer has a germline BRCA1 mutation informs her clinical management and that of her relatives. We sought an optimal strategy for identifying carriers using family history, breast cancer morphology and hormone receptor status data., Methods: We studied a population-based sample of 452 Australian women with invasive breast cancer diagnosed before age 40 years for whom we conducted extensive germline mutation testing (29 carried a BRCA1 mutation) and a systematic pathology review, and collected three-generational family history and tumour ER and PR status. Predictors of mutation status were identified using multiple logistic regression. Areas under receiver operator characteristic (ROC) curves were estimated using five-fold stratified cross-validation., Results: The probability of being a BRCA1 mutation carrier increased with number of selected histology features even after adjusting for family history and ER and PR status (P<0.0001). From the most parsimonious multivariate model, the odds ratio for being a carrier were: 9.7 (95% confidence interval: 2.6-47.0) for trabecular growth pattern (P=0.001); 7.8 (2.7-25.7) for mitotic index over 50 mitoses per 10 high-powered field (P=0.0003); and 2.7 (1.3-5.9) for each first-degree relative with breast cancer diagnosed before age 60 years (P=0.01).The area under the ROC curve was 0.87 (0.83-0.90)., Conclusion: Pathology review, with attention to a few specific morphological features of invasive breast cancers, can identify almost all BRCA1 germline mutation carriers among women with early-onset breast cancer without taking into account family history.

Women with mutations of the genes BRCA1 or BRCA2 are at increased risk of ovarian cancer. Oral contraceptives protect against ovarian cancer in general, but it is not known whether they protect against the disease in carriers of these mutations. We obtained self-reported lifetime histories of oral contraceptive use from 451 women who carried mutations of BRCA1 or BRCA2. We used conditional logistic regression to estimate the odds ratios associated with oral contraceptive use, comparing the histories of 147 women with ovarian cancer (cases) to those of 304 women without ovarian cancer (controls) who were matched to cases on year of birth, country of residence and gene (BRCA1 vs BRCA2). Reference ages for controls had to exceed the ages at diagnosis of their matched cases. After adjusting for parity, the odds-ratio for ovarian cancer associated with use of oral contraceptives for at least 1 year was 0.85 (95 percent confidence interval, 0.53-1.36). The risk decreased by 5% (1-9%) with each year of use (P for trend=0.01). Use for 6 or more years was associated with an odds-ratio of 0.62 (0.35-1.09). These data support the hypothesis that long-term oral contraceptive use reduces the risk of ovarian cancer among women who carry mutations of BRCA1 or BRCA2.

Germline mutations in the BRCA1 tumor suppressor gene are associated with increased risk for the development of ovarian cancer. All such cancers thus far reported have been of the epithelial histologic type. We identified an ovarian dysgerminoma in a 16-year-old woman (proband) with a family history of ovarian cancer during a review of histopathologic characteristics of ovarian cancers from women enrolled in the Gilda Radner Familial Ovarian Cancer Registry. Mutation analysis of DNA from this patient's peripheral blood leukocytes revealed a germline BRCA1 mutation (3312insG). The mutation was also present in the mother with breast cancer, a maternal aunt and a distant cousin with ovarian cancer, and a maternal grandfather and an uncle with skin cancer. The development of the proband's dysgerminoma may be unrelated to her germline BRCA1 mutation. Alternatively, such dysgerminomas may be caused by BRCA1 mutations, but occur so infrequently compared with epithelial cancers that they are seldom identified. Analysis of a larger series of ovarian germ cell tumors may resolve this question.

Background: The two-hit hypothesis for the genesis of cancer predicts that cancer can develop when the wild-type allele of a tumor suppressor gene is lost in an individual with a germline mutation in that gene. Neither loss of heterozygosity (LOH) for BRCA1 nor mutations of the TP53 (also known as p53) gene have been documented prior to invasion in ovarian cancers arising in women with germline BRCA1 mutations. Such documentation is difficult because lesions are rarely identified in ovarian epithelium. We, therefore, looked for LOH at microsatellite polymorphisms linked to the BRCA1 and TP53 tumor suppressor loci in an incidental carcinoma in situ of the ovary removed prophylactically from a woman with a germline BRCA1 mutation., Methods: By use of laser-capture microdissection, we obtained pure populations of atypical ovarian epithelial cells and normal stromal cells. DNA was extracted, amplified with primers flanking polymorphic microsatellites linked to BRCA1 (D17S855 and D17S579) and TP53 (TP53 and D17S786), and analyzed for LOH at these microsatellites. We also tested for p53 expression in the abnormal epithelium by immunohistochemistry., Results: Both of the markers linked to TP53 showed LOH, as did an intragenic BRCA1-linked marker (D17S855). The other microsatellite marker for BRCA1 was uninformative. Immunohistochemical staining with an antibody to p53 showed strong immunoreactivity confined to the atypical epithelium., Conclusions: BRCA1, as well as TP53, can undergo LOH prior to stromal invasion in BRCA1-associated ovarian cancer. Strong immunoreactivity for p53 suggests the presence of mutated p53 in these cells as well. These findings suggest that loss of function of these two tumor suppressor genes occurs early in ovarian carcinogenesis in BRCA1 mutation carriers.

Purpose: Idiopathic slow-transit constipation is a severe disorder of unknown cause. The onset in early childhood and history of constipation or Hirschsprung's disease in close family relatives suggest that slow-transit constipation could have a genetic basis. Several germline mutations have been described in Hirschsprung's disease, including mutations of RET and the gene encoding its ligand glial cell-derived neurotrophic factor. The aim of this study was to screen a panel of 16 cases of familial idiopathic slow-transit constipation, including 4 families in which there were relatives with Hirschsprung's disease, for RET and glial cell-derived neurotrophic factor mutations previously identified in Hirschsprung's disease., Methods: Genomic DNA from 16 patients with slow-transit constipation and four relatives with Hirschsprung's disease was analyzed using single strand and heteroduplex conformation polymorphism analysis at two conditions and by direct DNA sequencing using the fluorescent dideoxy terminator method., Results: Although common sequence polymorphisms were demonstrated with a frequency comparable with published data, no published or new mutation was seen in any of the exons of RET or glial cell-derived neurotrophic factor., Conclusions: Mutation of RET or glial cell-derived neurotrophic factor is not a frequent cause of idiopathic slow-transit constipation.

To determine the contribution of BRCA1 and BRCA2 mutations to the pathogenesis of male breast cancer in Hungary, the country with the highest male breast cancer mortality rates in continental Europe, a series of 18 male breast cancer patients and three patients with gynecomastia was analyzed for germ-line mutations in both BRCA1 and BRCA2. Although no germ-line BRCA1 mutation was observed, 6 of the 18 male breast cancer cases (33%) carried truncating mutations in the BRCA2 gene. Unexpectedly, none of them reported a family history for breast/ovarian cancer. Four of six truncating mutations were novel, and two mutations were recurrent. Four patients (22%) had a family history of breast/ovarian cancer in at least one first- or second-degree relative; however, no BRCA2 mutation was identified among them. No mutation was identified in either of the genes in the gynecomastias. These results provide evidence for a strong genetic component of male breast cancer in Hungary.

E-cadherin germ-line mutations have recently been described as a molecular basis for early-onset familial gastric cancer in Maori kindred. We screened 18 gastric cancer families of European origin for germ-line mutations to determine the proportion in which E-cadherin mutations occur and the clinical characteristics of the affected families. Truncating mutations were identified in three kindred with familial diffuse gastric cancer. In these families, the age of onset of gastric cancer was variable, the penetrance was incomplete, and one kindred contained individuals with cancers at other sites. Here, we show that a proportion of diffuse gastric cancer families of European origin have germ-line E-cadherin mutations; however, these mutations are absent in intestinal gastric cancer families.