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PubMed2001

[Bilateral breast carcinoma and local recurrence: prevalence of BRCA-1 and BRCA-2 gene mutations in an unselected patient sample].

BACKGROUND: Mutations of the BRCA 1/BRCA 2 genes strongly predispose towards the development of contralateral breast cancer. We therefore investigated a hospital-based series of patients with bilateral breast cancer and a comparison group of patients with unilateral breast cancer, pairwise matched by age and family history, for mutations of the BRCA 1/BRCA 2 genes. PATIENTS AND METHODS: Between 1995 and 2000 genomic DNA from blood samples of 75 patients with bilateral breast cancer, who received postoperative radiotherapy, was analyzed for mutations of all coding regions and flanking intron sequences of the BRCA 1/BRCA 2 genes by single strand conformation polymorphism analysis (SSCP) and sequencing of aberrant findings. The results were compared to 75 unilateral breast cancer patients who were screened for common mutations in the BRCA 1 and BRCA 2 genes. Treatment results of patients with bilateral disease were analyzed with regard to a possible carriership of a BRCA 1/BRCA 2 gene mutation. RESULTS: Five distinct frameshift deletions (one in BRCA 1, four in BRCA 2) were identified in six patients with bilateral breast cancer. Three of six carriers developed local relapse, whereas this was the case in only nine of 69 non-carriers. After radiotherapy local relapse occurred in five patients (five of 126 irradiated breasts or chest walls). Three of these patients (60%) were carriers of a pathogenic BRCA 1/BRCA 2 mutation. In the comparison group of patients with unilateral breast cancer three pathogenic BRCA 1 mutations were identified. CONCLUSIONS: We failed to confirm an increased prevalence of BRCA 1/BRCA 2 mutations in our hospital-based series of patients with bilateral breast cancer. However, local relapse, especially when occurring after radiotherapy, may be predictive for an underlying pathogenic BRCA 1 and BRCA 2 gene mutation in patients with bilateral breast cancer.

Adult↗

PubMed2003

Histopathological characteristics of BRCA1- and BRCA2-associated intraperitoneal cancer: a clinic-based study.

The aim of the research was to assess possible histopathological differences between BRCA1- and BRCA2-associated malignant intraperitoneal (ovarian/fallopian tube/peritoneal) tumors and their sporadic counterparts. Dutch families harboring pathogenic BRCA1 or BRCA2 mutations were selected. Included were patients who had had malignant primary ovarian, fallopian tube or peritoneal tumors. Histopathological data was compared with data obtained from the Dutch cancer registry between 1989 and 1993 (reference group). A total of 63 with primary intraperitoneal malignant tumors were identified in 41 families. Non-epithelial malignant tumors were not observed in the study group versus 6% (n = 404) in the reference group (n = 6789, P = 0.04). These tumors were excluded from further analysis, as were ovarian adenocarcinomas not otherwise specified, since these were detected in 22% of the study group, and in 19% of the reference group (P = 0.76). Serous carcinomas were detected in 94% (47/50) of the women in the study group in contrast to 62% (3145/5088) of the reference group (P < 0.01). In the study group, mucinous and endometrioid ovarian adenocarcinomas and serous ovarian borderline tumors each comprised 2.0% of the tumors. Clear cell ovarian carcinomas were not detected. In contrast, these percentages were 16% (P < 0.01), 10% (P = 0.07), 7% (P = 0.16) and 5% (P = 0.12), respectively, in the reference group. In the study group, 6.0% of the carcinomas arose in the fallopian tube versus 1.9% in the reference group (P = 0.03). Four percent of the study group developed primary serous peritoneal carcinomas, versus six percent in the reference group (P = 0.57). Serous carcinoma is the predominant type of intraperitoneal malignancy occurring in women harboring BRCA1 or BRCA2 mutations. Non-epithelial cancer does not seem to be part of the tumor spectrum of BRCA mutation carriers. This suggests, therefore, that serous tumors may be the only subtype related to a BRCA1 or BRCA2 mutation. Furthermore, fallopian tube carcinoma occurred more often in BRCA mutation carriers than in the reference population.

Adult↗

PubMed2000

BRCA1 and BRCA2 mutations in ovarian cancer: Covariation with specific cytogenetic features.

We analyzed 37 primary invasive carcinomas for BRCA1 and BRCA2 mutations by screening the entire coding regions of both genes. Seven predicted truncating mutations (four in BRCA1 and three in BRCA2) and one novel BRCA1 missense variant (S1542C) were identified (8/37, 22%). Two of the BRCA1 mutations were somatic changes, whereas the remaining three BRCA1 changes and all mutations of BRCA2 were found to be of germline origin. All eight BRCA-positive tumors were serous or seropapillary carcinomas (8/27 serous tumors, 30%), and all but one were poorly differentiated. The correlation between tumor karyotype and BRCA status showed that clonal chromosomal aberrations were present in all BRCA-positive tumors (8/8) compared with 20 of 29 BRCA-negative ones. The most consistently affected region in BRCA-positive tumors was the long arm of chromosome 6; alterations within this arm with a breakpoint in band 6q21 were seen in four of five BRCA1-positive and in two of three BRCA2-positive tumors, but only in four of 20 karyotypically abnormal tumors without BRCA mutations, suggesting that the genetic pathways of tumor progression differ in the two groups. The high frequency of germline BRCA mutations detected in this pilot study (16% of 37 invasive carcinomas) points to the need for more extended analyses of population-based series of patients to determine the true contribution of these predisposing genes to the overall incidence of ovarian cancer in this population.

Journal Article↗

PubMed1998

New mechanism of BRCA-1 mutation by deletion/insertion at the same nucleotide position in three unrelated French breast/ovarian cancer families.

A novel complex mutation consisting of a small deletion/insertion (3958del5ins4) was found in the breast cancer-1 gene (BRCA-1) in three unrelated French breast and/or ovarian cancer families. These mutations occurred at the same nucleotide position of the 3' end of exon 11. The wild-type sequence, CTCAG, was deleted and replaced by AGGC in the three families. The consequence is the generation of a stop codon, TAG, resulting in a truncated protein. We propose two different mechanisms to explain the generation of this complex mutation: (i) the simultaneous occurrence of a deletion and an insertion in a stem-loop structure and (ii) the abortive integration of a human transposable element (Tigger 1) that deleted 5 nucleotides and inserted a 4-nucleotide "scar", corresponding to the 5' extremity of the transposon.

BRCA1 Protein↗

PubMed1999

Breast conservation therapy for invasive breast cancer in Ashkenazi women with BRCA gene founder mutations.

BACKGROUND: Germline mutations in the BRCA1 and BRCA2 genes are associated with an increased risk of breast cancer. Whether women with breast cancer who have inherited mutations in these genes have a different outcome after breast conservation therapy than women with "sporadic" cancer is unresolved. Consequently, we compared the outcomes after breast conservation therapy in Ashkenazi women with or without germline mutations in BRCA1 and/or BRCA2 (hereafter called BRCA). METHODS: We studied 305 women of Ashkenazi Jewish descent undergoing breast-conserving treatment for 329 invasive breast cancers. We reviewed their clinical records, retrieved their archival tissue samples, and tested those samples for the founder mutations BRCA1 185delAG, BRCA1 5382insC, and BRCA2 6174delT. Genetic results were linked to clinical data and outcomes by univariate and multivariate analyses. All Pvalues are two-sided. RESULTS: We detected mutations in BRCA genes in 28 of 305 women. Women with BRCA mutations were more likely to be diagnosed with cancer before the age of 50 years (P<.001) and to have lymph node involvement (P =.04). Ipsilateral breast tumor recurrence was more common in women with BRCA mutations, although this did not reach statistical significance (relative risk [RR] = 1.79; 95% confidence interval [CI] = 0.64-5.03). Women with mutations were more likely to develop contralateral breast cancer (RR = 3.50; 95% CI = 1.78-8.74; P =.001). Distant disease-free survival was shorter in women with mutations (66.2% versus 84.3% at 10 years; P =.05), as was breast cancer-specific survival (71.9% versus 87.2% at 10 years; P =.02). Tumor stage and nodal status, but not mutation status, were predictive of distant disease-free and breast cancer-specific survival in multivariate analysis. CONCLUSIONS: Women with BRCA founder mutations are at increased risk for breast cancer-related events after breast conservation. However, mutation status is not an independent predictor of survival and should not influence decisions regarding adjuvant therapy. The increased contralateral breast cancer risk in women heterozygous for BRCA mutations mandates careful surveillance.

Analysis of Variance↗

PubMed2003

Ovarian surface epithelium: family history and early events in ovarian cancer.

Ovarian cancer is the most common cause of death from gynecological cancers in the Western world. There are many genetic and environmental factors which can influence a woman's risk of getting ovarian cancer. A strong family history of breast or ovarian cancer is definitely one of the most important and best-defined epidemiological risk factors. This review evaluates current knowledge of hereditary ovarian cancer. Histologic, cytologic and molecular studies on the ovarian surface epithelium (OSE), which is the origin of ovarian epithelial carcinomas, from women with a strong family history for ovarian carcinomas or with a mutation in one of the two known cancer susceptibility genes - BRCA1 and BRCA2, provide a background to facilitate understanding of the early changes in ovarian carcinogenesis. This overview is followed by a discussion of recent hypotheses and research on two questions. First, is there a mutational hotspot of BRCA mutation for ovarian cancer? Second, why do mutations in BRCA1 and BRCA2, which are ubiquitously expressed genes that participate in general cellular activities, lead preferentially to breast and ovarian cancer?

Animals↗

PubMed2004

Chromosomal mutagen sensitivity associated with mutations in BRCA genes.

Chromosomal mutagen sensitivity is a common feature of cells from patients with different kinds of cancer. A portion of breast cancer patients also shows an elevated sensitivity to the induction of chromosome damage in cells exposed to ionizing radiation or chemical mutagens. Segregation analysis in families of patients with breast cancer indicated heritability of mutagen sensitivity. It has therefore been suggested that mutations in low-penetrance genes which are possibly involved in DNA repair predispose a substantial portion of breast cancer patients. Chromosomal mutagen sensitivity has been determined with the G2 chromosome aberration test and the G(0) micronucleus test (MNT). However, there seems to be no clear correlation between the results from the two tests, indicating that the inherited defect leading to enhanced G(0) sensitivity is different from that causing G2 sensitivity. Less than 5% of breast cancer patients have a familial form of the disease due to inherited mutations in the breast cancer susceptibility genes BRCA1 or BRCA2. Heterozygous mutations in BRCA1 or BRCA2 in lymphocytes from women with familial breast cancer are also associated with mutagen sensitivity. Differentiation between mutation carriers and controls seems to be much better with the MNT than with the G2 assay. Mutagen sensitivity was detected with the MNT not only after irradiation but also after treatment with chemical mutagens including various cytostatics. The enhanced formation of micronuclei after exposure of lymphocytes to these substances suggests that different DNA repair pathways are affected by a BRCA1 mutation in accordance with the proposed central role of BRCA1 in maintaining genomic integrity. Mutations in BRCA1 and BRCA2 seem to predispose cells to an increased risk of mutagenesis and transformation after exposure to radiation or cytostatics. This raises a question about potentially increased risks by mammography and cancer therapy in women carrying a mutation in one of the BRCA genes. Lymphoblastoid cell lines (LCLs) from breast cancer patients have been used to study the mechanisms and genetic changes associated with tumorigenesis. With respect to mutagen sensitivity, conflicting results have been reported. In particular enhanced induction of micronuclei does not seem to be a general feature of LCLs with a BRCA1 mutation in contrast to lymphocytes with the same mutation. Therefore, LCLs are of limited utility for studying the mechanisms underlying chromosomal mutagen sensitivity.

BRCA1 Protein↗

PubMed2001

A probability model for predicting BRCA1 and BRCA2 mutations in breast and breast-ovarian cancer families.

Germline mutations in BRCA1 and BRCA2 genes predispose to hereditary breast and ovarian cancer. Our aim was to find associations between the clinical characteristics and positive mutation status in 148 breast cancer families in order to predict the probability of finding a BRCA mutation in a family. Several factors were associated with mutations in univariate analysis, whereas in multivariate analysis (logistic regression with backward selection) only the age of the youngest breast cancer patient and the number of ovarian cancer cases in a family were independent predictors of BRCA mutations. A logistic model was devised to estimate the probability for a family of harbouring a mutation in either BRCA1 or BRCA2. Altogether, 63 out of 148 families (43%) and 28 out of 29 (97%) mutation carrier families obtained probabilities over 10%. The mean probability was 55% for mutation-positive families and 11% for mutation-negative families. The models by Couch et al (1997) and Shattuck-Eidens et al (1997) previously designed for BRCA1 were also tested for their applicability to distinguish carrier families with mutations in either gene. The probability model should be a useful tool in genetic counselling and focusing the mutation analyses, and thus increasing also the cost-effectiveness of the genetic screening.

Adult↗

PubMedDate not supplied

BRCA1 and BRCA2 founder mutations in patients with bilateral breast cancer.

Bilateral breast cancer is traditionally considered an indirect indicator of inherited predisposition to cancer. To appreciate the contribution of genetic determinants to bilateral breast cancer in Jewish women we genotyped 55 such women for the three predominant mutations in BRCA1 (185delAG and 5382insC) and BRCA2 (6174delT) that account for the overwhelming majority of BRCA mutations in high-risk Jewish families. Among women with bilateral breast cancer, 17 mutation carriers (17/55; 29.6%) were identified. Individual mutation frequencies were 18.5% (10/55) for 185delAG, 3.7% (2/55) for 5382insC and 7.4% (5/55) for 6174delT. Carrier rate was significantly higher (P < 0.0016) in women with bilateral breast cancer whose first tumour was diagnosed at or before 42 years of age (82%; 14/17) than in women diagnosed after 42 years of age (7.9%; 3/38). Among patients with bilateral breast cancer and positive family history 45% (14/31) carried a BRCA mutation. Of these 86% (12/14) had one breast cancer diagnosed at or before 42 years of age. Our results suggest that bilateral breast cancer per se, in most cases, does not reflect genetic predisposition, unless associated with early age of onset (first tumour diagnosed at or before 42 years of age). Although the relationship between young age and carrier state in women with bilateral breast cancer is strong, no significant association between family history and carrier state was found. We can thus speculate that women with early onset breast cancer who carry a BRCA1 or BRCA2 mutation are prone to acquire a second breast tumour.

Adult↗

PubMed2000

Mutation analysis of BRCA1 and BRCA2 cancer predisposition genes in radiation hypersensitive cancer patients.

PURPOSE: The dose intensity of radiotherapy (RT) used in cancer treatment is limited in rare individuals who display severe normal tissue reactions after standard RT treatments. Novel predictive assays are required to identify these individuals prior to treatment. The mechanisms responsible for such reactions are unknown, but may involve dysfunction of genes involved in the sensing and response of cells to DNA damage. The breast cancer susceptibility genes BRCA1 and BRCA2 are implicated in DNA damage repair and the control of genome stability. The purpose of this study was to determine if clinical radiation hypersensitivity is related to mutations of the BRCA1 and BRCA2 genes. Such information is of potential use in the clinical management of BRCA mutation carriers and their families. METHODS AND MATERIALS: Twenty-two cancer patients who developed severe normal tissue reactions after RT were screened for mutations of BRCA1 and BRCA2, using various methods including protein truncation testing, direct DNA sequencing, and a PCR-based BRCA1 exon 13 duplication test. RESULTS: No mutations were detected in the 22 patients tested, despite screening for the majority of commonly described types of mutations of BRCA1 and BRCA2. CONCLUSION: These early results suggest that genes other than BRCA1 and BRCA2 probably account for most cases of clinical radiation hypersensitivity, and that screening for mutations of BRCA1 and BRCA2 is unlikely to be useful in predicting response to radiotherapy. However, it has not been excluded that some BRCA1 or BRCA2 heterozygotes might experience unexpected RT toxicity; further BRCA mutation screening on radiation sensitive individuals is warranted.

BRCA2 Protein↗

PubMed2004

Chromosomal radiosensitivity in BRCA1 and BRCA2 mutation carriers.

PURPOSE: The chromosomal radiosensitivity of a selected group of familial breast cancer patients carrying a mutation in BRCA1 (n=11) or BRCA2 (n=9) and a group of healthy mutation carriers (n=12) was investigated and compared to a reference group of breast cancer patients without a BRCA1/2 mutation (n=78) and a group of healthy women carrying no mutation (n=58). MATERIALS AND METHODS: The chromosomal radiosensitivity was assessed with the G2 and the G0-micronucleus (MN)-assay on fresh blood samples and on Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines. For the MN-assay, lymphocytes were exposed in vitro to 3.5 Gy and 2 Gy 60Co gamma-rays at a high dose rate (HDR) or low dose rate (LDR). 70-h post-irradiation cultures were arrested and micronuclei were scored in 1000 binucleate cells. For the G2-assay lymphocytes were irradiated in vitro with a dose of 0.4 Gy 60Co gamma-rays after 71h incubation. Cultures were arrested 90 min after irradiation and chromatid breaks were scored in 50 metaphases. RESULTS: The group of breast cancer patients with a BRCA1 or 2 mutation was on average more radiosensitive than the control group, but not different from breast cancer patients without a BRCA mutation. The radiation response of healthy BRCA1/2 carriers was not significantly different from the control group and also not different from relatives without a BRCA mutation. Comparing the radiation response in EBV cell lines derived from breast cancer patients with or without a BRCA1 mutation revealed no significant difference. CONCLUSIONS: Our results reveal that chromosomal radiosensitivity observed in breast cancer patients heterozygous for BRCA1 or 2 mutations, could not be demonstrated in healthy BRCA1/2 mutation carriers. This suggests that mutations in BRCA1 or 2 genes are not playing a main role in chromosomal radiosensitivity, this although BRCA1 and 2 are both involved in DNA repair/signalling processes.

BRCA1 Protein↗

PubMed2005

Appropriateness of breast-conserving treatment of breast carcinoma in women with germline mutations in BRCA1 or BRCA2: a clinic-based series.

BACKGROUND: Although BRCA1 and BRCA2 were identified in 1994 and 1995, respectively, to the authors' knowledge the optimal management of women with BRCA-associated breast carcinoma remains incompletely defined. The current study evaluates the appropriateness of breast-conserving therapy (BCT) in women with BRCA mutations. METHODS: Between May 1992 and October 2003, 87 female participants in genetic testing protocols were identified who 1) were found to have deleterious germline BRCA mutations and 2) reported a history of invasive breast carcinoma that was treated with wide local excision and radiation therapy. Clinical records were reviewed and follow-up was updated. RESULTS: The 87 subjects underwent BCT for 95 invasive breast tumors (8 women received BCT for metachronous bilateral tumors). In all 95 treated breasts, the 5-year and 10-year probabilities of metachronous ipsilateral breast carcinoma (MIBC) were 11.2% and 13.6%, respectively. Among the 87 subjects, the 5-year and 10-year probabilities of metachronous contralateral breast carcinoma (CBC) after treatment of the index tumor were 11.9% and 37.6%. No clinical factors were identified that were associated with either MIBC or CBC, including the use of tamoxifen or chemotherapy. CONCLUSIONS: Women with BRCA-associated breast carcinoma who undergo BCT appear to have risks of MIBC that are similar to those reported for young women without known mutations. The indications for unilateral mastectomy in this group of women should be the same as those for women with nonhereditary carcinoma. However, significant risks of CBC and possibly late MIBC may prompt the serious consideration of bilateral mastectomy as a preventive measure.

Adult↗

PubMed2006

High proportion of BRCA1/2 founder mutations in Hispanic breast/ovarian cancer families from Colombia.

In South America, a high proportion of the population is of Hispanic origin with an important representation in Colombia. Since nothing is known about the contribution of BRCA1 and BRCA2 germline mutations to hereditary breast/ovarian cancer in the Hispanic population from Colombia, we conducted the first study of 53 breast/ovarian cancer families from this country. Comprehensive BRCA mutation screening was performed using a range of techniques, including DHPLC, SSCP, and PTT, followed by DNA sequencing analysis. Thirteen deleterious germline mutations (24.5%) were identified in 53 families, comprising eight in BRCA1 and five in BRCA2. The two recurrent BRCA1 mutations, 3450 delCAAG and A1708E, accounted for 100% of all BRCA1 mutations identified in this cohort and the recurrent 3034 delACAA BRCA2 mutation for 40% of all BRCA2 mutations. Haplotype analyses suggested that each of these mutations has arisen from a common ancestor. The prevalence of BRCA1 or BRCA2 mutations was 50% in multiple case breast cancer families, and was 33% for the breast-ovarian cancer families. Our findings show that BRCA mutations account for a substantial proportion of hereditary breast/ovarian cancer in Colombia. The spectrum of mutations differed completely to that previously reported in Hispanic families of predominantly Mexican origin from Southern California [1] suggesting that specific genetic risk assessment strategies for the different Hispanic populations in South America and in the United States need to be developed.

Adult↗

PubMed2006

Clinical characteristics affect the impact of an uninformative DNA test result: the course of worry and distress experienced by women who apply for genetic testing for breast cancer.

PURPOSE: DNA mutation testing for breast cancer usually yields an uninformative result, which is a negative result in the absence of a known BRCA mutation within the family. However, few data are available on the psychological impact of this result. Moreover, the clinical heterogeneity within this group has not yet been considered. This study provides prospective data about the course of cancer-specific worry and distress for different groups of test applicants. PATIENTS AND METHODS: All DNA test applicants (n = 238) completed three questionnaires: before and 1 and 7 months after disclosure of a DNA mutation test. With repeated-measures analysis of variance, differences were assessed between BRCA1/2-positive women (n = 42), BRCA1/2-true-negative women (n = 43), and women with an uninformative test result (n = 153). RESULTS: On the group level, women with an uninformative result seemed to be reassured after disclosure (P < .001), but to a lesser extent than those women who received a true-negative result. However, not all women with an uninformative result reacted similarly: higher levels of worry and distress could be explained by relatively straightforward clinical variables, namely a personal history of cancer (P < or = .001) and a higher pedigree-based risk (P < or = .005). Furthermore, these clinical variables determined whether these women were either comparable to women who received a true-negative result or to BRCA mutation carriers. CONCLUSION: Women with an uninformative result form a heterogeneous group of test applicants. The subpopulation of those with both a personal history of cancer and a relatively high pedigree-based risk expressed the highest levels of worry 7 months after DNA testing.

Adult↗

PubMed2001

Hormonal prevention of hereditary breast cancer.

Women who carry a mutation in the BRCA1 or BRCA2 genes face a lifetime risk of developing breast cancer that approaches 80%. Among women with predisposing BRCA mutations, the risk of breast cancer is influenced by environmental factors and by modifying genes. Through the study of cohorts of female BRCA1 and BRCA2 carriers, several modifying factors have been identified. The risk of breast cancer is increased by early parity and is decreased by breast feeding, by oophorectomy, and by cigarette smoking. Many of the stragegies for breast cancer prevention involve estrogen deprivation and it is important to consider the acute and long-term effects of induced menopause in young women at high risk for breast cancer. There are no data so far on whether hormonal replacement therapy is hazardous in carriers of BRCA mutations.

Adult↗

PubMed2006

Prevalence of BRCA1 and BRCA2 mutations in Pakistani breast and ovarian cancer patients.

Among Asian countries, Pakistan has the highest rates of breast and ovarian cancer. To assess the contribution of the BRCA1 and BRCA2 germ line mutations to these high rates, we conducted the first study of 176 Pakistani breast and ovarian cancer patients, selected on family history and on age of diagnosis. Comprehensive BRCA mutation screening was performed using a range of techniques, including denaturing high-pressure liquid chromatography, single strand conformational polymorphism analysis and protein truncation test, followed by DNA sequencing. Thirty deleterious germ-line mutations were identified in the 176 families (17.0%), including 23 in BRCA1 and 7 in BRCA2. Four mutations, 185delAG, 185insA, S1503X and R1835X, were recurrent; these accounted for 52% of all identified BRCA1 mutations. Haplotype analyses suggested founder effects for 3 of these. The prevalence of BRCA1 or BRCA2 mutations was 42.8% for families with multiple cases of breast cancer, and was 50.0% for the breast/ovarian cancer families. The prevalence of mutations was 11.9% for single cases of early-onset breast cancer (< or =30 years) and was 9.0% for single cases of early-onset ovarian cancer (< or =45 years). Our findings show that BRCA mutations account for a substantial proportion of hereditary breast/ovarian cancer and early-onset breast and ovarian cancer cases in Pakistan.

Adult↗

PubMed2000

Life expectancy gains from cancer prevention strategies for women with breast cancer and BRCA1 or BRCA2 mutations.

CONTEXT: Women with BRCA1- or BRCA2-associated breast cancer are at increased risk for contralateral breast cancer and ovarian cancer and therefore may consider secondary cancer prevention strategies, such as prophylactic surgery and tamoxifen therapy. It is not proven to what extent these strategies reduce risk of second cancers in such patients. OBJECTIVE: To examine the effect of tamoxifen therapy, bilateral prophylactic oophorectomy (PO), prophylactic contralateral mastectomy (PCM), and combinations of these strategies on life expectancy for women with unilateral breast cancer and a BRCA1 or BRCA2 gene mutation. DESIGN AND SETTING: Decision analysis using a Markov model. Probabilities for developing contralateral breast cancer and ovarian cancer, dying from these cancers, dying from primary breast cancer, and the reduction in cancer incidence and mortality due to prophylactic surgeries and/or tamoxifen were estimated from published studies. PARTICIPANTS: Hypothetical breast cancer patients with BRCA1 or BRCA2 mutations facing decisions about secondary cancer prevention strategies. INTERVENTIONS: Seven strategies, including 5 years of tamoxifen use, PO, PCM, and combinations of these strategies, compared with careful surveillance. MAIN OUTCOME MEASURES: Total and incremental life expectancy (LE) with each intervention strategy. RESULTS: Depending on the assumed penetrance of the BRCA mutation, compared with surveillance alone, 30-year-old early-stage breast cancer patients with BRCA mutations gain in LE 0.4 to 1.3 years from tamoxifen therapy, 0.2 to 1.8 years from PO, and 0.6 to 2.1 years from PCM. The magnitude of these gains is least for women with low-penetrance mutations (assumed contralateral breast cancer risk of 24% and ovarian cancer risk of 6%) and greatest for those with high-penetrance mutations (assumed contralateral breast cancer risk of 65% and ovarian cancer risk of 40%.) Older age and poorer prognosis from primary breast cancer further attenuate these gains. CONCLUSIONS: Interventions to prevent second cancers, particularly PCM, may offer substantial LE gain for young women with BRCA-associated early-stage breast cancer. Estimates of LE gain may help women and their physicians consider the uncertainties, risks, and advantages of these interventions and lead to more informed choices about cancer prevention strategies.

Adult↗

PubMed2006

Effects of oestrogens and anti-oestrogens on normal breast tissue from women bearing BRCA1 and BRCA2 mutations.

There is considerable interest in whether anti-oestrogens can be used to prevent breast cancer in women bearing mutations in the BRCA1 and BRCA2 genes. The effects of oestradiol (E2), tamoxifen (TAM) and fulvestrant (FUL) on proliferation and steroid receptor expression were assessed in normal breast epithelium taken from women at varying risks of breast cancer and implanted into athymic nude mice, which were treated with E2 in the presence and absence of TAM or FUL. Tissue samples were taken at various time points thereafter for assessment of proliferative activity and expression of oestrogen and progesterone receptors (ERalpha and PgR) by immunohistochemistry. Oestradiol increased proliferation in the breast epithelium from women carrying mutations in the BRCA1/2 genes, those otherwise at increased risk and those at population risk of breast cancer. This increase was reduced by both TAM and FUL in all risk groups. In the absence of E2, PgR expression was reduced in all risk groups but significantly more so in the BRCA-mutated groups. Subsequent E2 treatment caused a rapid, complete induction of PgR expression in the population-risk group but not in the high-risk or BRCA-mutated groups in which PgR induction was significantly delayed. These data suggest that the mechanisms by which E2 induces breast epithelial PgR expression are impaired in BRCA1/2 mutation carriers, whereas those regulating proliferation remain intact. We conclude that early anti-oestrogen treatment should prevent breast cancer in very high-risk women.

Adolescent↗