Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case Series unselected for family history: a combined analysis of 22 studies

Management of women at high risk for breast cancer: New imaging beyond mammography

The management of women with an increased lifetime risk of breast cancer is a difficult task. This is especially true for women with a documented mutation in a breast cancer susceptibility gene (BRCA), and also for those who tested negative for a mutation, but have a family history that is suggestive of familial breast cancer. Primary prevention by prophylactic mastectomy has been shown to reduce breast cancer incidence in these women, but this intervention is still not considered a "first-line" option in the majority of guidelines. Instead, secondary prevention (intensified surveillance) is recommended. However, due to the early onset of familial breast cancer, screening must start at a substantially younger age than in women at average risk. This, together with the fact that familial breast cancers may differ from sporadic cancers in many aspects, will have a significant impact on the design and on the success rates of surveillance protocols. This article describes the different management options that exist for women at increased genetic risk and provides a survey of the current evidence regarding mammographic and non-mammographic imaging techniques. The conclusion is that mammographic screening, with or without concomitant ultrasound and clinical breast examination, is probably not sufficient to ensure an early diagnosis of familial breast cancer. If MRI is integrated in surveillance programs, early diagnosis seems to be possible. Still, the efficacy of screening even with MRI is unclear in terms of morbidity and mortality, and this lack of evidence must be communicated to women at high genetic risk.

Breast Cancer and Pregnancy

This article addresses a challenging diagnostic and treatment dilemma encountered in the care of pregnant women-breast cancer. The treatment of a breast cancer is significantly affected by an ongoing pregnancy and may result in an increased risk for a poor outcome in the mother. The definition, incidence, mechanism, diagnosis, and treatment of breast cancer associated with pregnancy and the normal physiologic and endocrine changes in the breast during pregnancy that contribute to the difficulty encountered by practitioners in diagnosing and treating the disorder are reviewed. The risks associated with pregnancy after breast cancer treatment and the effect of pregnancy on lifetime risk for breast cancer in the general population and for women with mutations in BRCA1 and BRCA2 are also discussed.

Prophylactic Oophorectomy Reduces Breast Cancer Penetrance During Prospective, Long-Term Follow-Up ofBRCA1Mutation Carriers

Purpose

Breast cancer penetrance estimates in BRCA1 mutation carriers have varied from 40% to 85%; this heterogeneity has been attributed to variations in risk among different study populations. No study has taken oophorectomy status into account in estimating penetrance. Because prophylactic oophorectomy reduces breast cancer risk by approximately 50%, we hypothesized that population differences in oophorectomy prevalence might significantly influence breast cancer penetrance estimates.

Methods

Females from multiple-case breast/ovarian cancer families that segregate deleterious BRCA1 mutations were observed prospectively for breast cancer incidence and oophorectomy.

Results

Within this cohort, 33 cases of breast cancer developed in 98 women with deleterious BRCA1 mutations during follow-up, yielding an estimated cumulative lifetime breast cancer risk of 80%. This estimate increased to 94% when the study participants were censored at the time of oophorectomy. Six of the 33 mutation-positive women who underwent oophorectomy during follow-up developed breast cancer, compared with 27 of 65 mutation carriers with intact ovaries (hazard ratio = 0.38; 95% CI, 0.15 to 0.97). Estimates of absolute breast cancer risk demonstrated that the protective effect of oophorectomy was strongest among women who were premenopausal at the time of surgery. When surgical status was ignored, the strong protective effect of oophorectomy, coupled with the high prevalence of the procedure in these families, led to a significantly lower estimate of the breast cancer penetrance in BRCA1 mutation carriers.

Conclusion

Differing rates of oophorectomy likely represent an underappreciated basis for a portion of the heterogeneity in estimated breast cancer penetrance described in BRCA mutation carriers, particularly mutation carriers from extensively affected, multiple-case families.

Younger birth cohort correlates with higher breast and ovarian cancer risk in European BRCA1 mutation carriers

Mutations in the BRCA1 gene result in an elevated risk of breast cancer (BC) and ovarian cancer (OC). However, risk estimates vary depending on the study population and statistical methodology used, and there are indications that the birth cohort and location of the mutation influence cancer risk. We investigated the risks for BC and OC associated with BRCA1 mutations in a young cohort of female mutation carriers who were identified by molecular genetic testing and belonged to a genetically heterogeneous Central European population. The study included 106 healthy and 158 affected carriers identified at an Austrian risk evaluation center. Risk estimation employed the product limit method. The log rank test was used to compare different strata. The risk of developing cancer to age 70 was found to be 85% for BC (95% CI 75-97%) and 53% for OC (95% CI 37-68%). Female mutation carriers born in 1958 or later were subject to a significantly higher risk of BC (P=0.005; 27% vs. 46% to age 40) and OC (P=0.006; 2% vs. 8% to age 40) than those born earlier. Mutations in exon 11 were associated with lower BC risk than mutations in exons 1-10 (P=0.008) and exons 12-24 (P=0.0006). OC risk was not influenced by mutation location (P=0.86). We conclude that female BRCA1 mutation carriers should be counseled about their cohort-dependent cancer risk. Further research into variables that affect cancer risk and are amenable to modification (e.g., lifestyle-related factors) should be considered a priority.

Decision making and decision support for hereditary breast-ovarian cancer susceptibility

Genetic testing for disease susceptibility has the potential to revolutionize health care by allowing for individually tailored disease prevention strategies. To achieve this promise, patients and physicians must use the information obtained through genetic testing to make medical decisions that are consistent with patient preferences and that lead to reduced disease morbidity and mortality. However, decisions associated with genetic testing can be complex. In this article, the authors review decision making associated with genetic testing and the medical management of hereditary breast-ovarian cancer susceptibility. They focus on decisions regarding BRCA1/2 testing and prophylactic surgery among BRCA1 and BRCA2 mutation carriers. They highlight the role of patient preferences and decision support in this population. The studies reviewed indicate that although patients' preferences do predict genetic testing and management decisions, other factors also influence their decision making. In particular, the authors discuss the role of anxiety and worry in relation to testing and surgery decisions.

Nipple aspiration and ductal lavage in women with a germline BRCA1 or BRCA2 mutation

Introduction

The aim of this study was to collect serial samples of nipple aspirate (NA) and ductal lavage (DL) fluid from women with germline BRCA1/2 mutations in order to create a biorepository for use in identifying biomarkers of breast cancer risk.

Methods

Between March 2003 and February 2005, 52 women with germline BRCA1 or BRCA2 mutations (median age 43 years, range 27 to 65 years) were scheduled for six-monthly NA, DL and venesection. DL was attempted for all NA fluid-yielding (FY) and any non-FY ducts that could be located at each visit.

Results

Twenty-seven (52%) women were postmenopausal, predominantly (19/27) from risk reducing bilateral salpingo-oophorectomy (BSO). FY ducts were identified in 60% of all women, 76% of premenopausal women versus 44% of postmenopausal (P = 0.026). Eighty-five percent of women had successful DL. Success was most likely in women with FY ducts (FY 94% versus non-FY 71% (P = 0.049). DL samples were more likely to be cellular if collected from FY ducts (FY 68% versus non-FY 43%; P = 0.037). Total cell counts were associated with FY status (FY median cell count 30,996, range 0 to >1,000,000 versus non-FY median cell count 0, range 0 to 173,577; P = 0.002). Four women (8%) had ducts with severe atypia with or without additional ducts with mild epithelial atypia; seven others had ducts with mild atypia alone (11/52 (21%) in total). Median total cell count was greater from ducts with atypia (105,870, range 1920 to >1,000,000) than those with no atypia (174, 0 to >1,000,000; P ≤ 0.001).

Conclusion

It is feasible to collect serial NA and DL samples from women at high genetic risk of breast cancer, and we are creating a unique, prospective collection of ductal samples that have the potential to be used for discovery of biomarkers of breast cancer risk and evaluate the ongoing effects of risk reducing BSO. DL cellular atypia was not predictive of a current breast cancer and longer follow up is needed to determine whether atypia is an additional marker of future breast cancer risk in this population already at high genetic risk of breast cancer.

A weighted cohort approach for analysing factors modifying disease risks in carriers of high-risk susceptibility genes

The authors propose a novel approach to evaluate the effects of risk factors on disease risks in carriers of high-penetrance alleles in disease susceptibility genes. Most studies to date have utilised data collected on carriers identified through ongoing genetic testing programs. The advantage of this approach is that it allows relatively large numbers of affected and unaffected carriers to be identified rapidly. However, genetic testing is targeted at individuals with a strong family history of disease, so that the selection of carriers is not random with respect to disease status. Risk factors are often analysed by standard cohort analysis methods, but these can be biased in retrospective studies if subjects are selected on the basis of phenotype. To overcome this problem, a weighted cohort approach is proposed, under which individuals are weighted according to certain sampling probabilities in order to mimic a true cohort. The method is illustrated by analyses of data from the International BRCA1/2 Carrier Cohort Study (IBCCS). Simulations demonstrate that the method gives rate ratio estimates that are close to unbiased provided that the absolute disease risks are well estimated. The power to detect associations is, however, reduced compared with an unweighted approach.

[Hereditary predispositions to gynaecological cancers]

The breast, ovary and endometrial cancers are hereditary in 5 to 10% of the cases. These genetic predisposition syndromes can be classified into two major classes: ovarian cancer and breast cancer predisposition family cases (genes BRCA1 and BRCA2) and family cases of colon cancer, endometrial cancer and ovarian cancer (Lynch syndrome or HNPCC) (genes hMLH1, hMSH2, hMLH6). The estimate of the family and individual risk can contribute in a determining manner to the management of these patients, by the practice of screening or an adapted prevention. Indeed, the risk of cancer of an individual having a positive test for a gene of predisposition to breast cancer (BRCA1, BRCA2) or to the colon cancer (hMLH1, hMSH2, hMLH6) lies between 50 and 70% at the age of 70 years. The indication of a genetic test must be discussed within the framework of an oncogenetic consultation. An individual and family medical management ranging from simple monitoring to prophylactic surgery is proposed to these predisposed people.

Adult granulosa cell tumors of the ovary in two first-degree relatives

BACKGROUND

Known inherited mutations are responsible for approximately 10% of all epithelial ovarian cancers; however, prior to this report, sex cord-stromal ovarian tumors had not been documented in related females.

CASE

We report here on a mother and daughter, each diagnosed with rare, adult-type granulosa cell tumors of the ovary.

CONCLUSION

This novel report of granulosa cell tumors occurring in two first-degree relatives must be examined with reserve. No familial tendency has previously been documented, and our finding may be coincidental. However, if additional cases are reported and future research is undertaken, biological markers and inherited mutations for certain sex cord-stromal ovarian tumors may be identified. These advances could lead to targeted therapy and specific surveillance protocols with appropriate surgical interventions for high-risk patients.

Influence of selected lifestyle factors on breast and ovarian cancer risk in BRCA1 mutation carriers from Poland

It has been estimated that the lifetime risk of breast cancer among women who inherit a BRCA1 or BRCA2 mutation is as high as 80%, and the risk estimates for ovarian cancer range from 15 to 40%. Several environmental and lifestyle factors are believed to contribute to the development of breast cancer in the general population and it is of interest to establish if these factors operate among mutation carriers as well. To evaluate the effects of age of menarche, parity, breast-feeding, oophorectomy and oral contraceptive use, as well as smoking and coffee consumption, on the risks of breast and ovarian cancer, we conducted a matched case-control study of Polish women with BRCA1 mutations. There were 348 breast cancer patients, 150 ovarian cancer patients and similar numbers of age-matched controls. BRCA1 carriers with late age of menarche, lower parity and long-term breast-feeding were less likely to develop breast cancer. Oral contraceptives protected against ovarian cancer.

Mammographic breast density as an intermediate phenotype for breast cancer

The amount of radiologically dense breast-tissue appearing on a mammogram varies between women because of differences in the composition of breast tissue, and is referred to here as mammographic density. This review presents evidence that mammographic density is a strong risk factor for breast cancer, and that risk of breast cancer is four to five times greater in women with density in more than 75% of the breast than in women with little or no density in the breast. Density in more than 50% of the breast could account for about a third of breast cancers. The epidemiology of mammographic density is consistent with its being a marker of susceptibility to breast cancer. Twin studies have shown that the proportion of the breast occupied by density, at a given age, is highly heritable, and inherited factors explain 63% of the variance. Mammographic breast density has the characteristics of a quantitative trait and might be determined by genes that are easier to identify than those for breast cancer itself. The genes that determine breast density might also be associated with risk of breast cancer, and their identification is also likely to provide insights into the biology of the breast and identify potential targets for preventive strategies.

Lifetime risk of melanoma in CDKN2A mutation carriers in a population-based sample

BACKGROUND

Germline mutations in the CDKN2A gene have been linked to melanoma incidence in many families with multiple cases of the disease. Previous studies of multiple-case families have indicated that the lifetime risk (i.e., penetrance) of melanoma in CDKN2A mutation carriers is very high, ranging from 58% in Europe to 91% in Australia by age 80 years. In this study, we examined lifetime melanoma risk among CDKN2A mutation carriers using carriers who were identified in a population-based study of melanoma.

METHODS

Probands for the study were incident case patients with either first or subsequent melanoma who were identified in nine geographic regions in Australia, Canada, the United States, and Italy. A total of 3626 probands (53% participation rate) with adequate DNA for analysis were recruited and genotyped for CDKN2A mutations. From the 3550 probands whose DNA could be amplified by polymerase chain reaction of CDKN2A exons 1alpha, 2, and 3 and surrounding regions, 65 mutation carriers were identified. Melanoma histories in first-degree relatives of these probands were used to calculate the lifetime risk in CDKN2A mutation carriers using the kin-cohort method.

RESULTS

The risk of melanoma in CDKN2A mutation carriers was approximately 14% (95% CI = 8% to 22%) by age 50 years, 24% (95% CI = 15% to 34%) by age 70 years, and 28% (95% CI = 18% to 40%) by age 80 years. Eighteen probands had three or more first-degree relatives with melanoma, but only one was a carrier of a CDKN2A mutation.

CONCLUSIONS

CDKN2A mutation carriers in the general population have a much lower risk of melanoma than that suggested by estimates obtained from multiple-case families. The preponderance of familial clustering of melanoma occurs in families without identifiable mutations in CDKN2A.

Genetic epidemiology and public health: hope, hype, and future prospects

Genetic epidemiology is a rapidly expanding research field, but the implications of findings from such studies for individual or population health are unclear. The use of molecular genetic screening currently has some legitimacy in certain monogenic conditions, but no established value with respect to common complex diseases. Personalised medical care based on molecular genetic testing is also as yet undeveloped for common diseases. Genetic epidemiology can contribute to establishing the causal nature of environmentally modifiable risk factors, through the application of mendelian randomisation approaches and thus contribute to appropriate preventive strategies. Technological and other advances will allow the potential of genetic epidemiology to be revealed over the next few years, and the establishment of large population-based resources for such studies (biobanks) should contribute to this endeavour.

A new germline mutation in BRCA1 gene in a sicilian family with ovarian cancer

A group of 103 sicilian patients with hereditary and familiar breast and/or ovarian cancer were screened for Breast Cancer 1 gene (BRCA1) mutations by direct sequencing PCR products spanning the coding region and partial intronic regions of the BRCA1 gene. In this study, we report a new germline mutation in BRCA1 gene, not previously reported in the BIC database, in a woman with ovarian cancer at 46 years old. Mother's proband has been diagnosed the same histotype of ovarian cancer at 42 age. The mutational analyses that shown a 4843delC frameshift mutation in exon 16 of BRCA1 gene was extended to other family members including the proband's brother and her two sons. Direct automatic sequencing of DNA extracted from the lymphocytes showed exactly the same 4843delC frameshift mutation only in the brother. In conclusion, the characterization of this mutation could help in the identification of a founder mutation of sicilian area and this may provide significant advantages for genetic counselling.

Breast Cancer Risk Following Bilateral Oophorectomy in BRCA1 and BRCA2 Mutation Carriers: An International Case-Control Study

Purpose

The purpose of this study was to estimate the extent of protection offered against breast cancer by prophylactic oophorectomy in carriers of BRCA1 or BRCA2 mutations and to determine to what extent risk reduction varies with age at oophorectomy, age at diagnosis, and time elapsed since surgery.

Patients and Methods

We analyzed 1,439 patients with breast cancer and 1,866 matched controls derived from a registry of BRCA1 and BRCA2 carriers. We estimated odds ratios (ORs) of breast cancer for having had a bilateral oophorectomy, using conditional logistic regression, matched for parity and for oral contraceptive use.

Results

A previous history of oophorectomy was associated with a significant reduction in breast cancer risk of 56% for BRCA1 carriers (OR = 0.44; 95% CI, 0.29 to 0.66) and of 46% for BRCA2 carriers (OR = 0.57; 95% CI, 0.28 to 1.15). The risk reduction was greater if the oophorectomy was performed before age 40 (OR = 0.36; 95% CI, 0.20 to 0.64 for BRCA1 carriers) than after age 40 (OR = 0.53; 95% CI, 0.30 to 0.91). The protective effect was evident for 15 years post-oophorectomy (OR = 0.39; 95% CI, 0.26 to 0.57).

Conclusion

Oophorectomy is an effective means of reducing the risk of breast cancer in carriers of BRCA1 mutations. The data suggest oophorectomy is protective in BRCA2 carriers as well, but needs to be confirmed in other studies.

Population-based family studies in genetic epidemiology

Designs that involve families (the traditional strength of genetic epidemiology) and population-based sampling (the traditional strength of environmental epidemiology) allow investigation of both genes and environment, separately or together, and allow valid inference to the population. These case-control-family designs (including those involving twin pairs), can be regarded as retrospective cohort studies of relatives, and can be used for: determining familial risks and genetic models; estimating risk (penetrance) for measured genotypes; genetic association studies; stratifying risks by family history and known mutation status; and studying modifiers of risk in genetically susceptible individuals. Follow-up of families allows genetic and environmental risks to be studied prospectively. We discuss statistical methods, theoretical and practical strengths, limitations, and other issues. Given their versatility, population-based family studies could become a principal framework in epidemiology, and move genetics from its traditional focus on high-risk families to give it a wider clinical and population health relevance.

Predictive Genetic Testing for Hereditary Breast and Ovarian Cancer: Psychological Distress and Illness Representations 1 Year Following Disclosure

This prospective study evaluates emotional functioning and illness representations in 68 unaffected women (34 carriers/34 noncarriers) 1 year after predictive testing for BRCA1/2 mutations when offered within a multidisciplinary approach. Carriers had higher subjective risk perception of breast cancer than noncarriers. Carriers who did not have prophylactic oophorectomy had the highest risk perception of ovarian cancer. No differences were found between carriers and noncarriers regarding perceived seriousness and perceived control of breast and ovarian cancer. Mean levels of distress were within normal ranges. Only few women showed an overall pattern of clinically elevated distress. Cancer-specific distress and state-anxiety significantly decreased in noncarriers from pre- to posttest while general distress remained about the same. There were no significant changes in distress in the group of carriers except for ovarian cancer distress which significantly decreased from pre- to posttest. Our study did not reveal adverse effects of predictive testing when offered in the context of a multidisciplinary approach.

Quality-of-Life Effects of Prophylactic Salpingo-Oophorectomy Versus Gynecologic Screening Among Women at Increased Risk of Hereditary Ovarian Cancer

Purpose

Recommendations for women at high risk of ovarian cancer include periodic gynecologic screening (GS) and prophylactic bilateral salpingo-oophorectomy (PBSO). The aim of the current study was to determine the quality-of-life (QOL) effects of PBSO versus GS.

Patients and Methods

Questionnaire data were obtained from 846 high-risk women who had participated in this nationwide, cross-sectional, observational study. Forty-four percent of the women had undergone PBSO, and 56% had opted for GS. Topics addressed by the questionnaire included generic QOL, cancer-specific distress, endocrine symptoms, and sexual functioning.

Results

No statistically significant between-group differences were observed in generic QOL (Short Form-36), with women in both the PBSO and GS groups scoring similarly to the general population. Compared with GS, PBSO was associated with fewer breast and ovarian cancer worries (P < .001) and more favorable cancer risk perception (P < .05). However, the PBSO group reported significantly more endocrine symptoms (P < .001) and worse sexual functioning (P < .05) than the GS group. Eighty-six percent of women would choose PBSO again, and 63% would recommend it to a friend with familial risk of ovarian cancer.

Conclusion

PBSO had no measurable adverse impact on generic QOL of high-risk women. The favorable effects of PBSO in terms of reduced cancer worries and low perceived cancer risk need to be weighed against the increase in endocrine and sexual symptoms. Balanced information will help clinicians and high-risk women to make informed decisions about the optimal preventive health strategy.

Risk of ovarian cancer in BRCA1 and BRCA2 mutation-negative hereditary breast cancer families

Women from site-specific hereditary breast cancer families who carry a BRCA1 or BRCA2 mutation are at increased risk for ovarian cancer. It is less clear, however, whether individuals from hereditary breast cancer families who do not carry such a mutation are also at increased ovarian cancer risk. To determine whether women from BRCA mutation-negative hereditary breast cancer families are at increased risk for ovarian cancer, 199 probands from BRCA mutation-negative, site-specific breast cancer kindreds who consented to prospective follow-up at the time of genetic testing were identified. The incidence of new breast and ovarian cancers in probands and their families since receipt of their genetic test results was determined by questionnaire. The expected number of cancers and standardized incidence ratios (SIRs) were determined from age-specific cancer incidence rates from the Surveillance, Epidemiology, and End Results (SEER) program by using the method of Byar. All statistical tests were two-sided. During 2534 women-years of follow-up in 165 kindreds, 19 new cases of breast cancer were diagnosed, whereas only 6.07 were expected (SIR = 3.13, 95% confidence interval [CI] = 1.88 to 4.89; P < .001), and one case of ovarian cancer was diagnosed, whereas only 0.66 was expected (SIR = 1.52, 95% CI = 0.02 to 8.46; P = .48). These results suggest that women from BRCA mutation-negative, site-specific breast cancer families are not at increased risk for ovarian cancer.

Towards a dietary prevention of hereditary breast cancer

Inheritance of a deleterious mutation in BRCA1 or BRCA2 confers a high lifetime risk of developing breast cancer. Variation in penetrance between individuals suggests that factors other than the gene mutation itself may influence the risk of cancer in susceptible women. Several risk factors have been identified which implicate estrogen-induced growth stimulation as a probable contributor to breast cancer pre-disposition. The protein products of both of these genes appear to help preserve genomic integrity via their participation in the DNA damage response and repair pathways. To date, the evidence for a cancer-protective role of dietary nutrients, for the most part those with antioxidant properties, has been based on women without any known genetic pre-disposition and it is important to identify and evaluate dietary factors which may modify the risk of cancer in BRCA carriers. Here we propose that diet modification may modulate the risk of hereditary breast cancer by decreasing DNA damage (possibly linked to estrogen exposure) or by enhancing DNA repair. The prevention of hereditary breast cancer through diet is an attractive complement to current management strategies and deserves exploration.

Risk reduction of contralateral breast cancer and survival after contralateral prophylactic mastectomy in BRCA1 or BRCA2 mutation carriers

The clinical outcome of contralateral prophylactic mastectomy (CPM) in women with a BRCA1 or BRCA2 mutation and a personal history of invasive breast cancer is unknown. We identified a cohort of 148 female BRCA1 or BRCA2 mutation carriers (115 and 33, respectively) who previously were treated for unilateral invasive breast cancer stages I–IIIa. In all, 79 women underwent a CPM, while the other women remained under intensive surveillance. The mean follow-up was 3.5 years and started at the time of CPM or at the date of mutation testing, whichever came last, that is, on average 5 years after diagnosis of the first breast cancer. One woman developed an invasive contralateral primary breast cancer after CPM, whereas six were observed in the surveillance group (P<0.001). Contralateral prophylactic mastectomy reduced the risk of contralateral breast cancer by 91%, independent of the effect of bilateral prophylactic oophorectomy (BPO). At 5 years follow-up, overall survival was 94% for the CPM group vs 77% for the surveillance group (P=0.03), but this was unexpectedly mostly due to higher mortality related with first breast cancer and ovarian cancer in the surveillance group. After adjustment for BPO in a multivariate Cox analysis, the CPM effect on overall survival was no longer significant. Our data show that CPM markedly reduces the risk of contralateral breast cancer among BRCA1 or BRCA2 mutation carriers with a history of breast cancer. Longer follow-up is needed to study the impact of CPM on contralateral breast cancer-specific survival. The choice for CPM is highly correlated with that for BPO, while only BPO leads to a significant improvement in overall survival so far.

BRCA2: breaks, mistakes and failed separations

BRCA2 was identified in 1995, one year after BRCA1. In terms of knowledge of the function of its product, BRCA2 has remained the less well-characterised gene. Both BRCA1 and BRCA2 are closely implicated in the repair of double-strand breaks in DNA by homologous recombination, but beyond that a function for BRCA2 has been hard to discern. A recent study has extended the function of BRCA2 to the regulation of cell cleavage and separation. Other groups have also shown how BRCA2, RAD51 and DSS1 co-exist in a ménage à trois and how the disruption of any one of the three cohabitants can have disastrous consequences for the cell.

Ovarian carcinoma screening in women at intermediate risk: impact on quality of life and need for invasive follow-up

BACKGROUND

Women with family histories suggestive of an increased risk of ovarian carcinoma who have not had a deleterious BRCA1 or BRCA2 mutation identified are commonly suggested to consider ovarian carcinoma screening with transvaginal ultrasound and/or assessment of CA 125 levels. Limited information is available regarding the impact of this approach on either quality of life (QOL) or need for invasive follow-up in this group of women.

METHODS

From November 1999 to October 2002, 184 women at intermediate risk of ovarian carcinoma were enrolled in a prospective study. Participants were screened with twice yearly transvaginal ultrasound and CA 125 assessments. Impact on QOL was measured using the Mental Component Summary (MCS) score of the Medical Outcomes Studies Short Form-36. Need for invasive follow-up was determined by questionnaire and medical record review.

RESULTS

In the current study, 135 participants underwent > or = 1 follow-up assessment. During a mean of 19.8 months of follow-up, 12.9% of ultrasounds and 3.8% of CA 125 assessments were abnormal. The authors reported that 38.5% of participants had > or = 1 abnormal ovarian screen that required a short interval follow-up. Because of either abnormal bleeding or ultrasound abnormalities, 24% of participants underwent > or = 1 endometrial sampling. Controlling for a history of breast carcinoma and menopausal status, abnormal ovarian screening results were associated with a decrease in MCS score (P = 0.034), whereas the need for endometrial sampling was not (P = 0.87).

CONCLUSIONS

Ovarian carcinoma screening in women at intermediate risk was associated with a substantial rate of abnormal screen results, endometrial sampling, and in women with abnormal ovarian screening findings, a decrease in MCS scores. These findings may have important implications for women considering ovarian carcinoma screening and for the design of future ovarian carcinoma screening trials.

Modulation of aromatase expression by BRCA1: a possible link to tissue-specific tumor suppression

Mutations in BRCA1 increase risks of familial breast and ovarian cancers, particularly among premenopausal women. While BRCA1 plays an active role in DNA repair, this function alone may not be sufficient to explain why BRCA1-associated tumors predominantly occur in estrogen-responsive tissues. Aromatase is the rate-limiting enzyme in estrogen biosynthesis and a key target in breast cancer treatment. Aromatase expression in ovarian granulosa cells dictates levels of circulating estrogen in premenopausal women, and its aberrant overexpression in breast adipose tissues promotes breast cancer growth. Here, we show that BRCA1 modulates aromatase expression in ovarian granulosa cells and primary preadipocytes. The cyclic AMP-dependent expression of aromatase in ovarian granulosa cells is inversely correlated with the protein level of BRCA1. Importantly, transient knockdown of BRCA1 enhances aromatase expression in both ovarian granulosa cells and primary preadipocytes. We propose that BRCA1 deficiency in epithelial and certain nonepithelial cells may result in combined effects of aberrant estrogen biosynthesis and compromised DNA repair capability, which in turn may lead to specific cancers in the breast and ovary.

A high frequency of germline BRCA1/2 mutations in western Sweden detected with complementary screening techniques

Dominant inheritance is presumed in 6-10% of breast and ovarian cancers. Mutations in BRCA1 and BRCA2 genes are the most commonly identified causative genes in such families. The frequency of mutation carriers with breast/ovarian cancer depends on the population studied, and display considerable variation that coincides with ethnic and geographical diversity. Mutation analyses were performed in 143 families registered at the Cancer Genetic Counseling Clinic of western Sweden. In a thorough mutation screening procedure, the entire BRCA1 and BRCA2 genes were analyzed using a combination of complementary mutation detection techniques. Mutations in either BRCA1 or BRCA2 were detected in 36% (52 out of 143) of all screened families. All families were clinically evaluated regarding age at diagnosis, type of cancer and number of cancer cases in the family. Among high-risk families, the mutation detection rate was 39% (46 out of 117). The detection rate observed among families with cases of ovarian cancer (42 out of 62, 68%), was substantially higher than in families with only breast cancer (10 out of 81, 12%). Age at ovarian cancer did not seem to have an effect on the detection rate. The analyses revealed 11 frameshift mutations, 4 nonsense mutations and 2 large deletions. Notably, the BRCA1 c.3171ins5 mutation accounted for 34 of 52 (65%) identified mutations. Seven mutations are novel: BRCA1c.409_410del; c.1912T>G; c.2228_2229del; c.3029delA; c.3433delA, a large deletion covering exons 1-3 of BRCA1and one BRCA2 mutation; BRCA2c.6287_6290del. We have shown that the founder mutation BRCA1 c.3171ins5 has a great influence on western Swedish breast/ovarian cancer families along with a high number of mutations unique for the region. In order to achieve a high mutation detection rate we suggest a combination of several detection techniques.

Hereditary breast cancer growth rates and its impact on screening policy

Imaging is often performed yearly for the surveillance of BRCA1/2 mutation carriers and women at high familial breast cancer risk. Growth of cancers in carriers may be faster as these tumours are predominantly high grade. Quantitative data on tumour growth rates in these 2 groups are lacking. Here, we have examined 80 high-risk women under surveillance for tumour size at diagnosis and preceding examinations at mammography and/or MRI. Tumour volume doubling time (DT) was assessed in 30 cancers in BRCA1/2 mutation carriers and 25 non-carriers. Impact of age and menopausal status were also evaluated. Mean DT of all invasive cancers was shorter in carriers (45 days CI: 26-73) than non-carriers (84 days CI: 58-131) (P = 0.048). Mean age at diagnosis was lower in carriers (40 years) than non-carriers (45 years) (P = 0.007). At multivariable analysis only age (P = 0.03), not risk-group (P = 0.26) nor menopause (P = 0.58) correlated significantly with DT. The mean growth rate slowed down to half in each successive 10 years-older group. In conclusion, age at detection indicated the growth rates of hereditary and familial breast cancers. It is recommended that the screening frequency should be adjusted according to a woman's age and a high-sensitive biannual test may be appropriate before the age of 40 years.

Adjusting the estimated proportion of breast cancer cases associated with BRCA1 and BRCA2 mutations: public health implications

PURPOSE

Mutations in BRCA1 or BRCA2 genes increase breast cancer risk. Assuring reliability of information about these mutations is increasingly important to the health care community; mutation testing is becoming more widespread. We describe a methodology for assessing such information.

METHODS

Our approach integrates four interdependent epidemiologic parameters: (1) the probability of developing breast cancer, (2) the proportion of breast cancer cases with a BRCA1 or BRCA2 mutation, (3) the proportion of women that carries a mutation, and (4) the proportion of women with a mutation that develops cancer. We assess the plausibility of estimates of these parameters from published reports and commonly accessed information sources.

RESULTS

Assuming a fixed probability of developing breast cancer, the following estimates for the other three epidemiologic parameters are derived for women by age 70: 1% to 2% of all breast cancer cases are associated with a BRCA1 or BRCA2 mutation; 1 in 300 to 1 in 465 women carry a mutation; and 35 to 65% of mutation carriers develop breast cancer. Within these ranges, however, only selected combinations are plausible. The proportion of mutation-related breast cancer is lower than listed in some common information sources (1 to 2% vs 6%). Also, penetrance is somewhat lower and the carrier rate somewhat higher.

CONCLUSIONS

The four epidemiologic parameters can be integrated to test their plausibility. BRCA1 and BRCA2 mutations are associated with only one-third as many breast cancer cases in the general population as reported by commonly accessed information sources.

Epithelial Ovarian Cancer: A Review of Current Management

Epithelial ovarian cancer is the most lethal gynaecological cancer among women worldwide, with 6000 new cases diagnosed in the UK each year. Most women present with advanced disease, but, despite a good initial response to treatment, most relapse. The overall 5-year survival rate is 46%, although this drops to about 13% in women with advanced disease. Transvaginal ultrasound and the tumour marker CA125 are being investigated for screening in ongoing randomised trials. Treatment of ovarian cancer is dependent on clinical stage, and should always be managed within a multidisciplinary team. Most cases will require a pelvic clearance and adjuvant chemotherapy. Current guidelines by the National Institute of Clinical Excellence (NICE) recommend that first-line chemotherapy should include a platinum-based regimen with or without paclitaxel. Relapsed ovarian cancer is incurable; however, chemotherapy can improve quality of life and survival. Gene therapy, immunotherapy and signal transduction inhibitors are all potential future therapies, and are being investigated in ongoing clinical research. In this paper we review the literature on the epidemiology, pathology, clinical features and the current treatment options in epithelial ovarian cancer.

Chemoprevention: From research to clinical oncology

Chemoprevention is by now an emerging area of clinical oncology addressed to healthy individuals at higher risk for cancer, subjects with precancerous conditions, and patients who are at risk for a second primary cancer. The important results of large trials with various agents and the more accurate methods of risk assessment have already had implications in clinical practice. Recently, a number of compounds have shown to be clinically effective at various organ levels, often covering all the three settings of primary, secondary and tertiary prevention. There is proof today that at least 3 of the 4 'big killers' in oncology--breast, colon and prostate cancer--and oral cancer are to a certain extent preventable by chemopreventive drugs. The missing piece so far is lung cancer. The expanding molecular drug development is providing the tools for a more effective and safer molecular-targeted prevention. Combination chemoprevention and the use of agents with multiple effects are other particularly promising chemoprevention strategies.

Clinical and pathologic findings of prophylactic salpingo-oophorectomies in 159 BRCA1 and BRCA2 carriers

OBJECTIVE

To estimate the likelihood of occult cancer diagnosis at prophylactic oophorectomy in BRCA1 and BRCA2 carriers in different age groups and to determine the histopathology of these lesions.

METHODS

We describe a series of 159 female BRCA1 or BRCA2 carriers who underwent prophylactic oophorectomy at the University Health Network, Toronto from January 1, 1992 to June 30, 2004.

RESULTS

Seven (4.4%) occult cancers were detected at pathologic examination. None of the 159 subjects had clinical signs or symptoms of ovarian carcinoma prior to, or at the time of, surgery. Only two cancers were grossly visible at surgery. There were 94 BRCA1 carriers, of whom six were found to have an occult cancer (6.4%). In contrast, only one of the 65 BRCA2 carriers was found to have an occult cancer (1.5%). Three of the seven cases of occult malignancy involved the fallopian tube and not the ovaries.

CONCLUSION

Approximately 6% of BRCA1 carriers and 2% of BRCA2 carriers who undergo prophylactic salpingo-oophorectomy will be found to have occult carcinomas if the ovaries and tubes are rigorously examined. A significant proportion of these appear to originate in the fallopian tube. No cancers were detected among women who had the operation at age 39 or younger.

Impact of teenage oral contraceptive use in a population-based series of early-onset breast cancer cases who have undergone BRCA mutation testing

Oral contraceptive (OC) use in young women has been associated with an increased risk of breast cancer. This matched case-control study aims to elucidate the combined effects of OC use and genetic factors in a population-based series of BRCA1/2 mutation-tested early-onset breast cancers. A first invasive breast cancer was diagnosed in 259 women aged 40 years between 1990 and 1995 in the South Swedish Health Care Region. A total of 245 women were included in this study. Information on family history of cancer, reproductive factors, smoking and OC use was obtained from questionnaires or patient charts. Three age-matched controls per case were chosen from a prospective South Swedish cohort. Ever OC use and current OC use were not associated with breast cancer. Cases were more likely to have used OCs before age 20 years (adjusted odds ratio (OR) 2.10 (95% CI 1.32-3.33)) and before their first child (adjusted OR 1.63 (95% CI 1.02-2.62)). When stratified by age, the effect of early OC use was limited to women diagnosed prior to age 36 years (OR 1.53 (1.17-1.99) per year of OC use prior to age 20 years). The risks were similar for low-dose and high-dose OCs. The probability of being a BRCA1/2 mutation carrier was three times higher among cases who started OC use prior to age 20 years compared with cases who started at age 20 years or older or who had never used OCs. However, the duration of OC use was similar among cases with and without BRCA1/2 mutations. No association was seen with a first-degree family history of breast cancer. Each year of OC use prior to age 20 years conferred a significantly increased risk for early-onset breast cancer, while there was no risk associated with use after age 20 years.

Changes in body weight and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

BACKGROUND

Several anthropometric measures have been found to be associated with the risk of breast cancer. Current weight, body mass index, and adult weight gain appear to be predictors of postmenopausal breast cancer. These factors have been associated with a reduced risk of premenopausal breast cancer. We asked whether there is an association between changes in body weight and the risk of breast cancer in women who carry a mutation in either breast cancer susceptibility gene, BRCA1 or BRCA2.

METHODS

A matched case-control study was conducted in 1,073 pairs of women carrying a deleterious mutation in either BRCA1 (n = 797 pairs) or BRCA2 (n = 276 pairs). Women diagnosed with breast cancer were matched to control subjects by year of birth, mutation, country of residence, and history of ovarian cancer. Information about weight was derived from a questionnaire routinely administered to women who were carriers of a mutation in either gene. Conditional logistic regression was used to estimate the association between weight gain or loss and the risk of breast cancer, stratified by age at diagnosis or menopausal status.

RESULTS

A loss of at least 10 pounds in the period from age 18 to 30 years was associated with a decreased risk of breast cancer between age 30 and 49 (odds ratio (OR) = 0.47; 95% confidence interval (CI) 0.28-0.79); weight gain during the same interval did not influence the overall risk. Among the subgroup of BRCA1 mutation carriers who had at least two children, weight gain of more than 10 pounds between age 18 and 30 was associated with an increased risk of breast cancer diagnosed between age 30 and 40 (OR = 1.44, 95% CI 1.01-2.04). Change in body weight later in life (at age 30 to 40) did not influence the risk of either premenopausal or postmenopausal breast cancer.

CONCLUSION

The results from this study suggest that weight loss in early adult life (age 18 to 30) protects against early-onset BRCA-associated breast cancers. Weight gain should also be avoided, particularly among BRCA1 mutation carriers who elect to have at least two pregnancies.

Attitudes about genetic testing and genetic testing intentions in African American women at increased risk for hereditary breast cancer

PURPOSE

To evaluate attitudes about the benefits, limitations, and risks of genetic testing for BRCA1 and BRCA2 (BRCA1/2) mutations and explore testing intentions in African American women at increased risk for hereditary breast cancer.

METHODS

Attitudes and intentions were evaluated by telephone in African American women (n = 74) at moderate and high risk for having a BRCA1/2 mutation.

RESULTS

Attitudes about the benefits of genetic testing were endorsed at a higher rate relative to limitations and risks; however, only 30% of respondents indicated that they would definitely have testing. In regression analysis, women most likely to be considering testing were those with fatalistic beliefs about cancer and those who believed they had a BRCA1/2 mutation. Women who had two or more affected relatives were also most likely to be considering testing. Women who had a personal history of cancer and those who believed they were at high risk for developing breast cancer were most likely to report greater limitations and risks. Pros scores were higher among women older than age 50 and those who were unemployed.

CONCLUSION

Although African American women at moderate and high risk for BRCA1/2 mutations report favorable attitudes about genetic testing, interest in testing may be limited. Women affected with cancer and those who believe they are at a higher risk for developing breast cancer may be most concerned about the negative consequences of testing. Increased attention may need to be given to beliefs about genetic testing and testing motivations during genetic counseling with African American women.

Contribution of BRCA1 and BRCA2 germ-line mutations to the incidence of breast cancer in young women: results from a prospective population-based study in France

The prevalence of BRCA1/2 germ-line mutations was assessed in a prospective population-based series of early-onset breast cancer (BC) patients in France, and the usefulness of a clinical assessment of hereditary BC risk, based on multiple criteria including pedigree structure, was evaluated. Through the Rhone region BC registry, 232 women diagnosed with BC before 46 years of age were included. They were tested for BRCA1/2 mutations an average of 10 months after diagnosis. All the women were classified according to their family history of cancer: high risk of hereditary breast cancer (HBC), low risk of HBC, isolated BC, and unknown HBC risk. Deleterious mutations were observed in 21 women (9.1%): 15 (6.5%) BRCA1 and 6 (2.6%) BRCA2. Mutations were more prevalent in women who developed BC before age 41 than in women who developed BC between ages 41 and 45 (12.8% versus 5.2%, respectively, P = 0.04). A high prevalence of BRCA1/2 mutations was found among women in the high-risk category with particular family features (i.e., small family size, predominantly male pedigree, specific cancers; 23.5%) and among women with isolated BC before age 41 and with five or fewer close adult female relatives (16.6%). According to the 10% probability level recommended by the American Society of Clinical Oncology guidelines for genetic testing of cancer, BRCA1/2 mutation screening should be considered for all women diagnosed before age 41, except for those with isolated BC in a large pedigree including multiple unaffected female relatives. The clinical assessment of HBC risk that we have developed should help in the decision to perform genetic testing.

Intra-abdominal carcinomatosis after prophylactic oophorectomy in women of hereditary breast ovarian cancer syndrome kindreds associated with BRCA1 and BRCA2 mutations

OBJECTIVE

Prophylactic surgical removal of the ovaries has been offered for many years as a potential preventative of ovarian cancer in women deemed to be at increased hereditary risk for this disease. Now, it is possible to test for specific mutations of the BRCA1 and BRCA2 genes that render members of hereditary breast ovarian cancer (HBOC) syndrome families susceptible to cancer. Widespread intra-abdominal carcinomatosis, which mimics metastatic ovarian serous carcinoma, has been reported following oophorectomy in individuals at increased hereditary risk. This study was undertaken to examine and report particularly the occurrence of intra-abdominal carcinomatosis, as well as other cancers, following prophylactic oophorectomy in patients who carry cancer susceptibility mutations of BRCA1 and BRCA2 and to assess the cumulative risks for this disease in order to assist in developing appropriate surgical interventions, based on currently available information, and to counsel patients who choose prophylactic surgery, concerning the potential prognosis, thereafter.

METHODS

The Creighton University Hereditary Cancer Institute registry was searched for members of HBOC syndrome families who had undergone prophylactic oophorectomy. The histories and results of DNA testing for the BRCA1 and BRCA2 mutations carried in their families were recorded, tabulated and examined, and the aggregate data are reported along with pertinent details of those individuals who developed neoplastic diseases after prophylactic oophorectomy. All available histologic and cytologic materials of patients who were diagnosed with intra-abdominal carcinomatosis were reviewed, and life-table calculations were performed to assess cumulative risks for this disease following prophylactic oophorectomy.

RESULTS

From 72 HBOC syndrome families that carried either BRCA1 or BRCA2 cancer-associated mutations, 238 individuals who had undergone prophylactic oophorectomy were recorded in our registry between January 1985 and December 2002. During a mean follow-up of 9.3 years, cancers were diagnosed in 27 subjects, including 16 individuals with breast cancer and five patients with intra-abdominal carcinomatosis. Breast cancers were stage I in 10 of 12 proven carriers of cancer-associated mutations. All five cases of intra-abdominal carcinomatosis were serous carcinomas, and all occurred in BRCA1 mutation carriers. Histologic review of the prophylactically removed ovaries found borderline lesions in two cases, one with possible early stromal invasion. Two of the five patients who developed intra-abdominal carcinomatosis were among 78 patients in this series who were diagnosed and treated for breast cancer before prophylactic oophorectomy. A 3.5% cumulative risk for all mutation carriers and a 3.9% cumulative risk for BRCA1 mutation carriers were calculated through 20 years of follow-up after prophylactic oophorectomy.

CONCLUSIONS

Intra-abdominal carcinomatosis in our series was diagnosed only in BRCA1 mutation carriers. The calculated cumulative risks of developing intra-abdominal carcinomatosis after prophylactic oophorectomy in members of HBOC syndrome families, specifically those who carry deleterious mutations, are well below the estimated risks of ovarian cancer published in the literature for similar patients. Breast cancers, which tended to be small and localized, were the most common malignancy in BRCA1 and BRCA2 mutation carriers after prophylactic oophorectomy.

Surgical decisions made by 158 women with hereditary breast cancer aged <50 years

AIM

To establish the uptake of contralateral risk reducing mastectomy in women informed of their risks and options at time of diagnosis of their primary unilateral breast cancer.

METHODS

We have assessed the surgical choices of 70 women diagnosed with breast cancer <50 years as part of a family history surveillance program and fully informed about their contralateral risks and surgical options. We have compared this to women from other surgical clinics who were subsequently found to harbour a pathogenic BRCA1/2 mutation.

RESULTS

Sixty-five percent (13/20) of BRCA1/2 mutation carriers and 59% (n=20/34) of those at the highest level of risk pre-diagnosis (33+% lifetime risk) opted for contra-lateral mastectomy in the study sample. In contrast only 10% (n=9/88) women identified as mutation carriers from other clinics opted for such surgery.

CONCLUSIONS

We would suggest that women with a significant family history and therefore a high contra-lateral breast cancer risk, should have these risks and management options discussed at the time of diagnosis of breast cancer.

Lobulitis is a frequent finding in prophylactically removed breast tissue from women at hereditary high risk of breast cancer

The aim of this study was to investigate closely the nature of premalignant lesions that occur in prophylactically removed breast tissue from patients at hereditary high risk of breast cancer. Breast tissues obtained from 41 patients who underwent prophylactic mastectomy (pM) because of a hereditary high risk of breast cancer and control tissues from 82 age-matched healthy controls who underwent breast reduction surgery were screened for premalignant lesions. Premalignant and malignant lesions were more frequent (p = 0.0016) in pM samples (5/41) than in controls (1/82). Interestingly, lobulitis, defined as more than 100 lymphocytes and/or plasma cells per lobule in more than one section in morphologically normal lobules, was encountered in 21 of 41 (51%) pM patients, in contrast to only 8 of 82 (10%) controls (p < 0.0001). Preliminary observations indicate a predominance of T-cells in these infiltrates, in agreement with the already known frequent presence of lymphocytic infiltration in hereditary ductal in situ and infiltrating ductal/medullary carcinomas. This novel finding implies an immune reaction to an as yet unidentified antigen frequently present in women at hereditary high risk of breast cancer, possibly as part of an early carcinogenic event.

Clinical implications of the breast cancer susceptibility genes BRCA1 and BRCA2

Genetic testing for BRCA1 and BRCA2 mutations has become an important part of the practice of medical oncology and clinical genetics over the past decade. Increasing numbers of women are requesting a genetic test so that they may better understand their personal risks of breast and ovarian cancer, and so that they may take appropriate measures to reduce the risk. Several of the risk factors can be modified, including breastfeeding and the use of oral contraceptives. A significant number of women opt for preventive mastectomy or oophorectomy, which will dramatically reduce the risks of breast and ovarian cancer. Chemoprevention with tamoxifen is still uncommon, largely due to women's fears of the side effects of the drug. A number of studies have shown that magnetic resonance imaging is superior to conventional mammography in terms of the early detection of breast cancer in the high-risk population. This article explores what is known about assessing genetic risk and the evidence supporting a range of preventive strategies.

Psychological functioning in African American women at an increased risk of hereditary breast and ovarian cancer

Despite attention to psychological issues during genetic counselling and testing for hereditary breast and ovarian cancer risk, limited information is available on cancer-specific distress among African American women being targeted for participation in counselling and testing. Therefore, the purpose of this study is to examine cancer-specific distress in African American women at an increased risk of hereditary breast and ovarian cancer and to identify factors having significant associations with distress in this population. Respondents were 141 African American women identified for participation in genetic counselling and testing for BRCA1/2 mutations. Overall, respondents reported moderate levels of cancer-specific distress. Younger age (coefficient=6.0, p=0.001), being unemployed (coefficient=-5.0, p=0.01), and having a personal history of cancer (coefficient=5.0, p=0.02) had significant associations with intrusion. Younger age was also associated significantly with greater avoidance (r=6.0, p=0.02). These results suggest that African American women aged 50 and younger, those who are unemployed and women with a personal history of breast or ovarian cancer may be the most vulnerable to experiencing elevated levels of distress during genetic counselling and testing. Greater attention to psychological issues, including concerns about cancer and cancer risks, may be needed during genetic counselling and testing for BRCA1/2 mutations with these women.

Cancer risk prediction models: a workshop on development, evaluation, and application

Cancer researchers, clinicians, and the public are increasingly interested in statistical models designed to predict the occurrence of cancer. As the number and sophistication of cancer risk prediction models have grown, so too has interest in ensuring that they are appropriately applied, correctly developed, and rigorously evaluated. On May 20-21, 2004, the National Cancer Institute sponsored a workshop in which experts identified strengths and limitations of cancer and genetic susceptibility prediction models that were currently in use and under development and explored methodologic issues related to their development, evaluation, and validation. Participants also identified research priorities and resources in the areas of 1) revising existing breast cancer risk assessment models and developing new models, 2) encouraging the development of new risk models, 3) obtaining data to develop more accurate risk models, 4) supporting validation mechanisms and resources, 5) strengthening model development efforts and encouraging coordination, and 6) promoting effective cancer risk communication and decision-making.

Oral contraceptive use and risk of early-onset breast cancer in carriers and noncarriers of BRCA1 and BRCA2 mutations

BACKGROUND

Recent oral contraceptive use has been associated with a small increase in breast cancer risk and a substantial decrease in ovarian cancer risk. The effects on risks for women with germ line mutations in BRCA1 or BRCA2 are unclear.

METHODS

Subjects were population-based samples of Caucasian women that comprised 1,156 incident cases of invasive breast cancer diagnosed before age 40 (including 47 BRCA1 and 36 BRCA2 mutation carriers) and 815 controls from the San Francisco Bay area, California, Ontario, Canada, and Melbourne and Sydney, Australia. Relative risks by carrier status were estimated using unconditional logistic regression, comparing oral contraceptive use in case groups defined by mutation status with that in controls.

RESULTS

After adjustment for potential confounders, oral contraceptive use for at least 12 months was associated with decreased breast cancer risk for BRCA1 mutation carriers [odds ratio (OR), 0.22; 95% confidence interval (CI), 0.10-0.49; P < 0.001], but not for BRCA2 mutation carriers (OR, 1.02; 95% CI, 0.34-3.09) or noncarriers (OR, 0.93; 95% CI, 0.69-1.24). First use during or before 1975 was associated with increased risk for noncarriers (OR, 1.52 per year of use before 1976; 95% CI, 1.22-1.91; P < 0.001).

CONCLUSIONS

There was no evidence that use of current low-dose oral contraceptive formulations increases risk of early-onset breast cancer for mutation carriers, and there may be a reduced risk for BRCA1 mutation carriers. Because current formulations of oral contraceptives may reduce, or at least not exacerbate, ovarian cancer risk for mutation carriers, they should not be contraindicated for a woman with a germ line mutation in BRCA1 or BRCA2.

[Molecular alterations in breast cancer: clinical implications and new analytical tools]

PURPOSE

Breast cancer is a complex and heterogeneous disease resulting from various molecular alterations, the identification of which should have profound impact on the management of patients.

CURRENT KNOWLEDGE AND KEY POINTS

The discovery of germline mutations within breast cancer susceptibility genes, such as BRCA1 and BRCA2, which are associated with a major risk of breast cancer during lifetime, has improved the assessment of the individual risk toward the disease, allowing appropriate strategies of screening and prevention. The identification of key molecular actors in the mammary oncogenesis may help to better assess the prognosis of the disease, while providing new therapeutic targets. Large-scale molecular technologies, which allow simultaneous assessment of a high number of molecular parameters in a single assay, should provide new tools to tackle complexity and heterogeneity of breast cancer. Hence, by examining transcriptional profiles of breast cancer using DNA microarrays, it was possible to reveal new prognostic tumor subgroups, previously indistinguishable. Further improvements are awaited with the recent development of high throughput and large-scale technologies investigating the tumor proteome.

PROSPECTS AND PROJECTS

Precise knowledge of molecular alterations involved in each individual breast cancer will allow more effective and less toxic, tailored therapies.