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

Breast cancer genetics: unsolved questions and open perspectives in an expanding clinical practice

Breast cancer is the most common cause of cancer death in the United Kingdom, with a lifetime risk of one in nine in women. Only 5-10% of all cancers is thought to be due to strongly penetrant inherited predisposing genes, such as BRCA1 and BRCA2. However, other less penetrant genes, including some autosomal recessive genes, are likely to be of etiological importance in other families. This review addresses the current knowledge of breast cancer susceptibility genes and explores the possibilities for future developments. Features of tumor pathology, prognosis, and the scope for targeted treatments in mutation carriers are discussed, and the management of known carriers and those at increased risk for developing breast cancer are evaluated. Genetic testing for cancer susceptibility may become widely available in the future, and has important ethical and management implications.

BayesMendel: an R environment for Mendelian risk prediction

Several important syndromes are caused by deleterious germline mutations of individual genes. In both clinical and research applications it is useful to evaluate the probability that an individual carries an inherited genetic variant of these genes, and to predict the risk of disease for that individual, using information on his/her family history. Mendelian risk prediction models accomplish these goals by integrating Mendelian principles and state-of-the-art statistical models to describe phenotype/genotype relationships. Here we introduce an R library called BayesMendel that allows implementation of Mendelian models in research and counseling settings. BayesMendel is implemented in an object-oriented structure in the language R and distributed freely as an open source library. In its first release, it includes two major cancer syndromes: the breast-ovarian cancer syndrome and the hereditary non-polyposis colorectal cancer syndrome, along with up-to-date estimates of penetrance and prevalence for the corresponding genes. Input genetic parameters can be easily modified by users. BayesMendel can also serve as a generic tool for genetic epidemiologists to flexibly implement their own Mendelian models for novel syndromes and local subpopulations, without reprogramming complex statistical analyses and prediction tools.

Highly penetrant hereditary cancer syndromes

The past two decades have brought many important advances in our understanding of the hereditary susceptibility to cancer. Approximately 5-10% of all cancers are inherited, the majority in an autosomal dominant manner with incomplete penetrance. While this is a small fraction of the overall cancer burden worldwide, the molecular genetic discoveries that have resulted from the study of families with heritable cancer have not only changed the way these families are counselled and managed, but have shed light on molecular regulatory pathways important in sporadic tumour development as well. In this review, we consider 10 of the more highly penetrant cancer syndromes, with emphasis on those predisposing to breast, colon, and/or endocrine neoplasia. We discuss the prevalence, penetrance, and tumour spectrum associated with these syndromes, as well as their underlying genetic defects.

Cancer genetics in primary care

The cloning of two major breast cancer susceptibility genes, BRCA1 and BRCA2, in 1994 and 1995 and the subsequent development of commercial genetic testing has brought hereditary cancer genetics into the public eye. In addition to DNA-based genetic testing, new strategies and treatments have been developed to provide accurate assessment of cancer risk and to reduce the chances of cancer developing in the future. This increasing scientific and public attention has prompted some cancer patients and their families to find out whether they "have the cancer gene" and has placed more responsibility on primary care clinicians to identify people who should be referred for specialized services of hereditary cancer genetics.

Analysis of the time interval between diagnoses in women with double primary breast and ovarian or primary peritoneal cancers

OBJECTIVES

The time interval between diagnoses of breast and epithelial ovarian cancer is not well established in women with dual primary tumors of both organ sites. Our goals were to examine the time interval between diagnoses and identify any relationship to clinicopathologic factors.

METHODS

We identified 49 patients who developed both cancers. These patients were divided into two groups: group 1 patients developed breast cancer first, group 2 patients had ovarian before breast cancer. The risk of a BRCA1 or BRCA2 mutation in our study subjects was estimated using the BRCAPRO. Parameters were compared using either the chi(2) or the Kruskal-Wallace test.

RESULTS

There were 26 and 23 patients in groups 1 and 2, respectively. The mean time interval was longer in group 2 (86 vs. 45 months; P = 0.013). Median PFS and OS were longer in group 2 for both cancers [PFS: 161 vs. 61 months for breast (P = 0.85) and 132 vs. 39 months for ovarian (P = 0.019); OS: 250 vs. 115 months for breast (P = 0.77) and 277 vs. 42 months for ovarian (P = 0.0013)]. OS was longer in group 2 for both cancers combined 217 vs. 115 (P = 0.026). The estimated risk of BRCA mutation was at least 20% in the majority of the patents.

CONCLUSIONS

Our data indicates that the time interval between the diagnosis of breast and ovarian carcinomas is 4 years. In contrast, the time interval between the diagnosis of ovarian and breast carcinomas is 7 years. These results could be useful in counseling women at risk.

Penetrances of breast and ovarian cancer in a large series of families tested for BRCA1/2 mutations

Accurate estimates of breast and ovarian cancer penetrance in BRCA1/2 mutation carriers are crucial in genetic counseling. Estimation is difficult because of the low frequency of mutated alleles and the often-uncertain mechanisms of family ascertainment. We estimated the penetrances of breast and ovarian cancers in carriers of BRCA1/2 mutations by maximizing the retrospective likelihood of the genetic model, given the observed test results, in 568 Italian families screened for germline mutations. The software BRCAPRO was used as a probability calculation tool in a Markov Chain Monte Carlo approach. Breast cancer penetrances were 27% (95% CI 20-34%) at age 50 years and 39% (27-52%) at age 70 in BRCA1 carriers, and 26% (0.18-0.34%) at age 50 and 44% (29-58%) at age 70 in BRCA2 carriers, and ovarian cancer penetrances were 14% (7-22%) at age 50 and 43% (21-66%) at age 70 in BRCA1 carriers and 3% (0-7%) at age 50 and 15% (4-26%) at age 70 in BRCA2 carriers. The new model gave a better fit than the current default in BRCAPRO, the likelihood being 70 log units greater; in addition, the observed numbers of mutations in families stratified by gene and by cancer profile were not significantly different from those expected. Our new penetrance functions are appropriate for predicting breast cancer risk, and for determining the probability of carrying BRCA1/2 mutations, in people who are presently referred to genetic counseling in Italy. Our approach could lead to country-customized versions of the BRCAPRO software by providing appropriate population-specific estimates.

BRCA1 and BRCA2 mutations as prognostic factors in bilateral breast cancer patients

BACKGROUND

Incidence of primary bilateral breast cancer (BC) is rare and does not exceed 5%. BRCA1/2 mutation carriers diagnosed with breast cancer have a strong life time risk of developing contralateral breast cancer (53% versus 2%).

PATIENTS AND METHODS

A group of 108 patients with bilateral breast cancer, who reported at our Cancer Centres from 2000 to 2002, were subjected to genetic testing. Similarities and differences between BRCA1/2 carriers and non-carriers were analysed in terms of family history, pathology of tumour, age of diagnosis, developing contralateral BC and second primary cancer.

RESULTS

BRCA1/2 mutations were detected in 32 of 108 patients. Family history of BC was identified in 46.9% of these patients compared with 22.4% of non-carriers (P <0.05). Synchronous BC was diagnosed significantly rarer [4 of 32 (12.5%)] in BRCA1/2 carriers than in the non-carrier group [26 of 76 (34.2%)]. In addition, patients with BRCA mutations were younger when they were diagnosed than non-carriers. BRCA1/2 carriers had a significantly higher incidence of medullary BC (13.6% versus 1.7%) and developed ovarian cancer significantly more frequently than non-carriers (12 of 32 and 1 of 72 patients, respectively).

CONCLUSIONS

Patients with bilateral BC having BRCA mutations are significantly younger than non-carriers. They also have a significantly higher family history of BC and an increased risk of developing ovarian cancer. The differences in clinical aspects of BRCA carriers with bilateral BC should be considered in clinical management.

BRCA1 and BRCA2: 1994 and beyond

The discovery of the first gene associated with hereditary breast cancer, BRCA1, was anticipated to greatly increase our understanding of both hereditary and sporadic forms of breast cancer, and to lead to therapeutic and preventive breakthroughs. Much has been learned during the past decade about the genetic epidemiology of breast cancer, the ethnic distribution and clinical consequences of BRCA1 and BRCA2 mutations, and the central role of DNA repair in breast cancer susceptibility. The ability to translate this knowledge into novel treatments, however, remains elusive.

Psychological distress in women at increased risk for breast cancer: the role of risk perception

The magnetic resonance imaging screening (MRISC) study evaluates a surveillance programme for women with a hereditary risk for breast cancer. The psychological burden of surveillance in these women may depend on inaccurate risk perceptions. To examine differences in risk perceptions between three predefined risk categories and associations with psychological distress. BC-specific distress, general distress, and RP (cognitive and affective) were assessed, two months before a surveillance appointment. Cumulative lifetime risk (CLTR) of developing breast cancer was trichotomised into: (1) CLTR of 60-85% (mutation carriers), (2) CLTR of 30-50%, and (3) CLTR of 15-30%. In a total group of 351 women (mean age 40.5 years, range 21-63 years) the three risk categories significantly differed in their accuracy of assessing cognitive risk perceptions. In category 1, 60% had an accurate risk perceptions, in category 2, 43.7% and in category 3, 33.3%. Overestimators reported significantly more breast cancer-specific distress. After adding affective risk perception to the model, this effect disappeared. Affective risk perceptions showed significant associations with breast cancer-specific and general distress. Affective risk perception is a more important determinant for psychological distress than cognitive risk perception. This knowledge should be used during surveillance appointments in order to improve and individualise support for these women.

Clinical validity and clinical utility of genetic tests

In considering the appropriate use of new genetic tests, clinicians and health care policymakers must consider the accuracy with which a test identifies a patient's clinical status (clinical validity) and the risks and benefits resulting from test use (clinical utility). Genetic tests in current use vary in accuracy and potential to improve health outcomes, and these test properties may be influenced by the clinical setting in which the test is used. In addition, the relative importance of clinical validity and utility varies according to the proposed use of the test. This unit defines clinical validity and clinical utility, provides examples, and considers the implications of these test properties for clinical practice.

Minority Recruitment in Hereditary Breast Cancer Research

Although recruitment of ethnic and racial minorities in medical research has been evaluated in several studies, much less is known about the methods used to recruit these populations to participate in cancer genetics research. This report reviews the resources that have been used to identify and recruit ethnic and racial minorities to participate in hereditary breast cancer research. Overall, hospital-based resources were used most often to identify potential subjects, and active recruitment methods were used most frequently to enroll eligible subjects. This review suggests that there appears to be a finite number of resources and strategies to identify and recruit potential subjects to participate in cancer genetics research; however, options for improving awareness about cancer genetics research among ethnic and racial minorities have not been extensively evaluated. To study ethnic and racial minority participation in cancer genetics research, stronger evaluation components will need to be integrated into research methods. Both observational and experimental studies are needed to determine resources that are most effective for identifying potential subjects who are ethnic and racial minorities and to evaluate the effects of different recruitment strategies on enrollment decisions among these populations.

The genetic epidemiology of breast cancer genes

Genetic susceptibility to breast cancer in women is conferred by a large number of genes, of which six have so far been identified. In the context of multiple-case families, BRCA1 and BRCA2 are the most important. Mutations in these genes confer high lifetime risks of breast cancer and ovarian cancer, and more moderate risks of prostate cancer and some other cancer types. Mutations in the CHEK2 and ATM genes, by contrast, cause much more modest (2-4 fold) risks of breast cancer. Genes so far identified explain approximately 20% of the familial aggregation of breast cancer. The remaining susceptibility genes have, so far, proved illusive, suggesting that they are numerous and confer moderate risks. A variety of techniques including genome-wide association studies, use of quantitative intermediate endpoints, and resequencing of genes may be required to identify them. The identification of such genes can provide a basis for targeted prevention of breast cancer.

The dawn of genetic testing for glaucoma

PURPOSE OF REVIEW

To review recent trends in genetic testing in medicine as they apply to newly evolving tests for patients with glaucoma.

RECENT FINDINGS

The utilization of powerful molecular methods for genetic testing is now entering its early stages in the practice of medicine in general, and with testing, many issues, both medical and societal, have been raised. Only recently has testing for a disease risk factor in primary open angle glaucoma (POAG) become available. It is known that some mutations in the gene myocilin are associated with POAG. MYOC.mt1 is a relatively common promoter region variant in the myocilin gene for which there is a commercially available test. Some investigators have found that MYOC.mt1 may increase disease severity in patients with POAG, whereas others have not found this association. There is a need for further testing for the role of the MYOC.mt1 variant in the pathogenesis of POAG.

SUMMARY

Genetic testing for glaucoma holds great promise. Currently available tests for disease-related tests in patients with glaucoma or at risk for this disease remain controversial.

Fertility Intentions Following Testing for a BRCA1 Gene Mutation

Objective: To test whether fertility intentions differed among persons who tested positive, tested negative, or did not know their genetic status for a mutation of the BRCA1 gene. Method: Participants were members of a large Utah-based kindred with an identified mutation at the BRCA1 locus. Participants received genetic counseling prior to testing and were interviewed at baseline before testing and at three points after receiving test results from a genetic counselor. The sample included men and women who completed all interviews, were between ages 18 and 45, and were fertile, resulting in a sample of 101 respondents. The primary dependent variable measured whether a subject indicated that they were moderately or very sure at all three post-testing interviews that they intended to have additional children. Effects of BRCA1 mutation status on fertility intentions were estimated using multivariate logistic regressions where we controlled for gender, age, marital status, and baseline fertility intentions. Results: Female carriers were less likely to want additional children in relation to female noncarriers (odds ratio 0.12, 95% confidence interval 0.01–1.23; P = 0.074). No differences were found among men. There was a significant difference in the effect of mutation status on fertility intentions between males and females (Gender × Carrier status interaction; P = 0.009). Persons who did not know their mutation status were less likely to want more children than noncarriers (odds ratio 0.09, 95% confidence interval 0.01–0.75; P = 0.027). Conclusion: Predictive genetic testing for late-onset cancer susceptibility affects family planning decision-making. Persons contemplating predictive testing should be informed about possible effects such testing may have on their plans for future fertility.

Epidemiology of breast cancer among BRCA mutation carriers: an overview

Mutations in BRCA1 and BRCA2 have been associated with an increased lifetime risk of breast and ovarian cancers. Many of the well-recognized risk factors and risk modifiers in other women appear to operate similarly in BRCA mutation carriers. However, current evidence suggests that BRCA-related breast cancer risk is positively associated with pregnancy and parity, while smoking may reduce the risk. The incidence of BRCA1-related breast cancer is high before the age of 35 years and oral contraceptive use for 5 or more years is associated with increased risk of this disease among women carrying BRCA1 mutations.

Impact of Genetic Testing for Breast–Ovarian Cancer Susceptibility

Previously, we have reported a clinical trial in which any woman in a defined geographic region who had a qualifying family history and who was referred by her physician or who was identified through a regional cancer registry was offered free genetic counseling, BRCA testing, and recommendations based on test results. Each family was represented by one affected and one unaffected person. Of the 87 families actually tested, 13 were found to have deleterious mutations. To assess the impact of the counseling and testing process, we contacted the tested individuals 1 month and 1 year after receiving the test result and those with an abnormal test result after 4 years. Index subjects, we found, differed significantly from relatives. Before coming for counseling, index subjects perceived both their general health and emotional health as worse than did their relatives. After counseling and testing, index subjects continue to worry more about breast cancer than do relatives. Affected subjects, we found, differed significantly from unaffected subjects. Before counseling, affected subjects knew more about breast cancer, perceived their general health as poorer, and reported greater adherence to recommended breast cancer surveillance than did unaffected subjects. After counseling and testing, affected subjects were less satisfied than unaffected subjects with having been tested. This study indicates that the group most prone to distress by cancer risk genetic counseling and testing is not the recruited relatives, nor even those affected with cancer, but rather the index patients themselves. The index patients, i.e., the ones who want the risk information most, appear to undergo the most stress in obtaining it.

Biology of Epithelial Ovarian Cancer: Implications for Screening Women at High Genetic Risk

Purpose

Our aim was to analyze the clinicopathologic features of screen-detected ovarian cancers identified in women, either at general population risk or high genetic risk of ovarian cancer, who have participated in screening studies.

Methods

Studies published between 1988 and April 2003 were categorized by the population screened and the primary screening modalities used. Each report was examined with reference to the histologic type, stage, and grade of screen-detected cancers. Reports of studies of prophylactically removed ovaries from women at high risk of ovarian cancer were also reviewed.

Results

Of the stage I tumors detected by screening women at population risk, almost half were borderline ovarian tumors, granulosa-cell tumors, or germ-cell tumors, which is disproportionate to their frequency. Furthermore, of the stage I invasive epithelial cancers diagnosed in women at population risk, the majority were endometrioid, clear-cell, and mucinous histologic subtypes. Most ovarian cancers that occur in women at high genetic risk are high-grade serous cancers, and these are infrequently screen detected at an early stage.

Conclusion

The clinicopathologic features of screen-detected ovarian cancers suggest that screening may not reduce mortality in women at increased genetic risk. Prospective screening studies are required in genetically high-risk populations to answer this important question. Women electing surveillance should be aware of the lack of proven benefit and the low likelihood of detecting early stage serous cancers. Bilateral salpingo-oophorectomy appears to be the most effective approach to decrease the risk of ovarian cancer and thereby reduce mortality in high-risk women.

Hormone Replacement Therapy and Life Expectancy After Prophylactic Oophorectomy in Women With BRCA1/2 Mutations: A Decision Analysis

Purpose

The decision about prophylactic oophorectomy is difficult for many premenopausal women with BRCA1/2 mutations because of concerns and controversy about the use of hormone replacement therapy (HRT) after oophorectomy.

Patients and Methods

A Markov decision analytic model used the most current epidemiologic data to assess the expected outcomes of prophylactic oophorectomy with or without HRT (to age 50 years or for life) in cohorts of women with BRCA1/2 mutations. Sensitivity analyses were conducted to assess the impact of alternative assumptions about effects of HRT, effects of prophylactic oophorectomy, and risks of cancer associated with BRCA1/2 mutations.

Results

In our model, prophylactic oophorectomy lengthened life expectancy in women with BRCA1/2 mutations, irrespective of whether HRT was used after oophorectomy. This gain ranged from 3.34 to 4.65 years, depending on age at oophorectomy. Use of HRT after oophorectomy was associated with relatively small changes in life expectancy (+0.17 to −0.34 years) when HRT was stopped at age 50, but larger decrements in life expectancy if HRT was continued for life (−0.79 to −1.09 years). HRT was associated with a gain in life expectancy of between 0.39 and 0.79 years for mutation carriers undergoing both prophylactic mastectomy and oophorectomy.

Conclusion

On the basis of the results of this decision analysis, we recommend that women with BRCA1/2 mutations undergo prophylactic oophorectomy after completion of childbearing, decide about short-term HRT after oophorectomy based largely on quality-of-life issues rather than life expectancy, and, if using HRT, consider discontinuing treatment at the time of expected natural menopause, approximately age 50 years.

Short- and Long-Term Impact of Receiving Genetic Mutation Results in Women at Increased Risk for Hereditary Breast Cancer

Forty-seven unaffected women from high-risk breast cancer families who had received results for hereditary breast/ovarian predisposition genes between 1 month and 5 years ago were interviewed regarding their experiences. Women responded to open-ended questions. The initial emotional turmoil reported by most was generally short lived. However, the impact of genetic testing went beyond the individual to the extended family and social context, particularly in the short-term. A common theme was the difficulty associated with divulging a result to family members, who were also adjusting to their own result. The majority of carriers reported advantages that were both physical (options for surveillance programs and prophylactic surgery) and emotional (reduced uncertainty, increased awareness of options and knowledge about risk, preparation time). Most carriers reported no change in lifestyle although some reported discovering their mutation status as a positive life-changing experience. Implications for genetic counseling and further research are discussed.

BRCA1 functions as a breast stem cell regulator

BRCA1 is an important susceptibility gene for breast cancer, which confers substantial lifetime risks of breast cancer, particularly in the pre-menopausal age group. Typically, carriers of BRCA1 mutations develop breast tumours that grow rapidly and are high grade and oestrogen receptor negative. They also possess a basal epithelial phenotype, as defined by cytokeratin expression, that is not present in most breast cancers. It has recently been proposed that the adult breast stem cell expresses only basal keratins. Others have indicated a CD44 positive, CD24 negative phenotype for breast cancer stem cells. In this paper, I argue that the biology of human BRCA1 and its rodent homologues and the clinicopathological features of breast cancer related to BRCA1 support the notion that one of the key functions of BRCA1 is to act as a stem cell regulator. This has implications for the management of carriers of mutations of BRCA1, in part because support for the role of BRCA1 as a stem cell regulator would emphasise the distinct nature of breast cancer related to BRCA1.

CLCA2 tumour suppressor gene in 1p31 is epigenetically regulated in breast cancer

The calcium-activated chloride channel gene family is clustered in the 1p31 region, which is frequently deleted in sporadic breast cancer. Recent studies have indicated the association of the second member of this gene family (CLCA2) with the development of breast cancer and metastasis. We have now shown the absence of expression of CLCA2 in several breast cancer tumours and cell lines, which confirms the results from other reports. When overexpressed in CLCA2-negative cell lines, their tumorigenicity and metastasis capability were significantly reduced, suggesting a tumour suppressor role for CLCA2 in breast cancer. The mechanisms behind the silencing of CLCA2 in breast cancer, however, have not been elucidated to date. Although we were able to identify CLCA2 mutations in breast cancers, somatic mutations are not the major cause of CLCA2 gene silencing. On the other hand, treatment of breast cancer CLCA2-negative cell lines with demethylating agents was able to restore CLCA2 expression, suggesting an epigenetic inactivation of this gene. Bisulphite-sequencing of the promoter-associated CpG island of the CLCA2 gene in breast tumours demonstrated that the absence of expression in these tumours was caused by hypermethylation of the promoter CpG island. In contrast, in breast cancer cell lines, tumours, and control cell lines that express CLCA2, a much lower level, and often absence, of methylation of the promoter were demonstrated. These findings demonstrate that CLCA2 is frequently inactivated in breast cancer by promoter region hypermethylation, which makes it an excellent candidate for the 1p31 breast cancer tumour suppressor gene.

A Counselling Model for BRCA1/2 Genetic Susceptibility Testing

When BRCA1/2 genetic susceptibility testing was introduced in the clinic in the mid-nineties, the "Huntington protocol" was used in the counselling of individuals applying for genetic testing. This protocol includes at least three sessions with a certain reflection period before blood sampling. Evidence on the psychological impact of BRCA1/2 genetic susceptibility testing has been accumulating in the last years. We will give a short overview of these psychological studies in order to reflect the need of using the extensive Huntington protocol in the counselling of individuals applying for BRCA1/2 genetic susceptibility testing. A shortened and more flexible BRCA1/2 counselling protocol is delineated, in which the attention is focused on the needs and strengths of the individual.

Progress and challenges in screening for early detection of ovarian cancer

Ovarian cancer is characterize by few early symptoms, presentation at an advanced stage, and poor survival. As a result, it is the most frequent cause of death from gynecological cancer. During the last decade, a research effort has been directed toward improving outcomes for ovarian cancer by screening for preclinical, early stage disease using both imaging techniques and serum markers. Numerous biomarkers have shown potential in samples from clinically diagnosed ovarian cancer patients, but few have been thoroughly assessed in preclinical disease and screening. The most thoroughly investigated biomarker in ovarian cancer screening is CA125. Prospective studies have demonstrated that both CA125 and transvaginal ultrasound can detect a significant proportion of preclinical ovarian cancers, and refinements in interpretation of results have improved sensitivity and reduced the false-positive rate of screening. There is preliminary evidence that screening can improve survival, but the impact of screening on mortality from ovarian cancer is still unclear. Prospective studies of screening are in progress in both the general population and high-risk population, including the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), a randomized trial involving 200,000 postmenopausal women designed to document the impact of screening on mortality. Recent advances in technology for the study of the serum proteome offer exciting opportunities for the identification of novel biomarkers or patterns of markers that will have greater sensitivity and lead time for preclinical disease than CA125. Considerable interest and controversy has been generated by initial results utilizing surface-enhanced laser desorption/ionization (SELDI) in ovarian cancer. There are challenging issues related to the design of studies to evaluate SELDI and other proteomic technology, as well as the reproducibility, sensitivity, and specificity of this new technology. Large serum banks such as that assembled in UKCTOCS, which contain preclinical samples from patients who later developed ovarian cancer and other disorders, provide a unique resource for carefully designed studies of proteomic technology. There is a sound basis for optimism that further developments in serum proteomic analysis will provide powerful methods for screening in ovarian cancer and many other diseases.

One in 10 ovarian cancer patients carry germ line BRCA1 or BRCA2 mutations

At least 10% of all ovarian cancers are estimated to have a hereditary background. Hereditary breast-ovarian cancer (HBOC) due to mutations in the BRCA genes is a major cause of hereditary ovarian cancer, although its frequency and relationship to age and family history in unselected series of ovarian cancers is not completely known. We report here the results of a full mutational screening analysis for germ line BRCA1 and BRCA2 mutations in 161 patients with invasive epithelial ovarian carcinomas. Age at diagnosis ranged from 22 to 82 years (mean 59 years). Deleterious (frame-shift, nonsense and missense) mutations were detected in 13/161 (8%) of the patients and affected BRCA1 in 12 cases and BRCA2 in one case. Four additional missense variants (one in BRCA1 and three in BRCA2) with a possible association with an increased risk ovarian cancer were revealed, resulting in a total frequency of BRCA gene alterations of 17/161 (11%). The 13 patients with deleterious mutations had a mean age of 57 years (range 41-76 years) and only three of these patients were below 50 years of age. A family history of at least one breast cancer and/or ovarian cancer was reported in all but 1 of the patients with BRCA mutations compared with only 24% of patients without mutations. Our findings in this prospective study confirm approximately 1 in 10 patients with ovarian cancer carry a germ line BRCA gene mutation associated with HBOC, and also indicate that a large number of these patients are over 50 years of age at diagnosis.

Peritoneal carcinoma in women with genetic susceptibility: implications for Jewish populations

Women from families with multiple cases of breast and ovarian cancer, specifically those who carry cancer-associated mutations of BRCA1 or BRCA2 are at increased life-time risk for peritoneal carcinoma, even after previous surgery to remove the ovaries, fallopian tubes and uterus. Hereditary breast-ovarian cancer (HBOC) syndrome and the associated BRCA1 and BRCA2 mutations are particularly prevalent in women of Jewish lineage, and specific BRCA1 and BRCA2 germline mutations have been linked with peritoneal carcinoma and HBOC syndrome in Jewish populations, especially those of Ashkenazi descent. This review presents the currently available data and looks forward toward further and better understanding of peritoneal carcinoma in women with inherited susceptibility. Over 90% of peritoneal cancer in patients from HBOC syndrome kindreds and associated with BRCA1 and BRCA2 mutations are serous carcinomas, which is equivalent with the proportion of ovarian cancers that are serous carcinomas in similar patients. The best indications are that while many peritoneal carcinomas in genetically susceptible women may arise directly from malignant transformation of the peritoneum, others might represent metastases from primary ovarian or fallopian tube carcinomas. Although the incidence of borderline ovarian tumors may not be increased in HBOC syndrome kindreds and those who carry cancer-associated BRCA1 and BRCA2 mutations, these individuals could be susceptible to malignant transformation of borderline lesions of the ovaries and peritoneum. Moreover, recent reports raise the question of possibly increased risk in Jewish carriers of germline BRCA1 mutations for uterine papillary serous carcinoma, which could be the source of metastasis to the peritoneum in some cases. The penetrance of cancer-associated BRCA1 mutations for ovarian cancer is estimated to be 11%-54%, and for BRCA2 mutations the penetrance for ovarian cancer is 11%-23%. So far, available screening methods appear to be insufficient for early detection of many ovarian cancers. Prophylactic oophorectomy has been found to reduce the risk for ovarian cancer in women from HBOC kindreds and those who carry cancer-associated BRCA1 and BRCA2 mutations, leaving a residual risk for peritoneal carcinomatosis of well less than 5%. Therefore, surgical removal of the ovaries, fallopian tubes and uterus, after child-bearing has been completed and by early in the fifth decade of life, are appropriate prophylactic procedures in women whose genetic susceptibility puts them at increased risk for cancers of mullerian tract origin, including ovarian and fallopian tube carcinomas and possibly serous carcinoma of the uterus. Hysterectomy, as well as salpingo-oophorectomy, removes the gynecologic organs targeted for malignant transformation in genetically susceptible women and simplifies decisions regarding hormone replacement therapy and chemical prophylaxis and treatment of breast cancer. Unless a transabdominal operative approach is otherwise indicated, laparoscopic-assisted transvaginal techniques are well suited for intra-abdominal exploration, cytology, biopsies and prophylactic salpingo-oophorectomy and hysterectomy in women with hereditary susceptibility to gynecologic cancer.

Prevention of breast cancer in women who carryBRCA1 orBRCA2 mutations: A critical review of the literature

The purpose of our study was to review the evidence for the efficacy of surveillance for early detection, bilateral prophylactic mastectomy, prophylactic oophorectomy and chemoprevention in preventing breast cancer and improving survival of BRCA1 or BRCA2 carriers. A critical review of journal articles published between 1998 and 2004 identified by searches of MEDLINE, PubMed and references of retrieved articles was undertaken. None of the current evidence is based on randomized studies. The efficacy of surveillance for early detection of breast cancer among BRCA1 or BRCA2 carriers is not yet established. Screening with clinical breast examination and mammography showed lower sensitivity in BRCA1 or BRCA2 carriers than in the general population. Screening with MRI might offer higher sensitivity rates than mammography. Prophylactic mastectomy was shown to significantly reduce the risk of breast cancer by 89.5-100%. However, of all strategies reviewed, mastectomy was the least acceptable to women at high risk. Tamoxifen use was associated with breast cancer prevention among BRCA2 carriers (RR=0.38, 95%CI: 0.06-1.56). In BRCA1 or BRCA2 carriers with breast cancer, tamoxifen use was associated with the prevention of secondary breast cancer (OR= 0.50, 95% CI: 0.28-0.89). Prophylactic oophorectomy was associated with hazard ratios for breast cancer of 0.47 (95%CI:0.29-0.77) and 0.32 (95%CI: 0.08-1.20), in retrospective and short follow-up prospective cohort studies, respectively. There is a pressing need for more studies in order to determine which of the 4 strategies alone, or in combination, is the most effective for the prevention of breast cancer and for the improvement of survival of BRCA mutation carriers.

Hereditary breast cancer in Jews

A family history of breast cancer poses higher risks for Jewish versus non-Jewish women, particularly for early-onset breast cancer. This appears to be due in large part to the high prevalence (2.5%) of three BRCA1 and BRCA2 founder mutations in Ashkenazi Jews. About 4 to 8% of non-Jewish male breast cancer cases versus 19% of Jewish male breast cancer cases carry germline BRCA mutations. Jewish women are disproportionately impacted by BRCA mutations throughout life, with a 10% carrier rate for breast cancer diagnosed at any age and a 21 to 30% carrier rate for breast cancer diagnosed by age 40. Comparable rates in non-Jewish populations are 6.1% for breast cancer diagnosed before age 50. Lifetime penetrance estimates based on genotyping of probands have ranged widely in Jewish and non-Jewish populations. However, a study of 1008 Jewish women with breast cancer which extended genotyping to relatives found high penetrance rates with considerably smaller standard errors. This study and studies of early-onset incident breast cancer in non-Jews have found that at least half of high-risk cases would be missed by family history screening alone. While the carrier rate in non-Jewish populations is too low to consider genetic screening, the carrier rate in Ashkenazi Jews is high and genetic screening poses fewer technical barriers. The high genetic attributable cancer risks of Ashkenazi BRCA founder mutations, the sobering lethality of ovarian and early onset breast cancers, and the increasing clarity about effectiveness of medical interventions make imperative further dialogue and research to keep guidelines for genetic screening up to date.

Hereditary ovarian cancer in Ashkenazi Jews

Ovarian cancer is the fourth leading cause of cancer deaths among American women. While women in both the Ashkenazi and non-Ashkenazi populations have an estimated 1.7% lifetime risk of acquiring malignancy, the proportion of hereditary ovarian cancer is much higher in the Ashkenazim. Most of this increased proportion of hereditary ovarian cancer risk is accounted for by inherited mutations in the BRCA1 and BRCA2 genes. In the Ashkenazi Jewish population, 29 to 41% of ovarian cancer is believed to be secondary to inheriting one of three founder mutations in BRCA 1 and BRCA 2, while only 10% of ovarian cancer is attributed to mutations of these genes in non-Ashkenazim. In the US population in general, it is estimated that between 1 out of 345 and 1 out of 1000 individuals carries a BRCA mutation, compared with approximately 1 in 40 individuals of Ashkenazi Jewish descent. The ovarian cancer risk up to age 70 associated with BRCA mutation carriers has been reported to be as high as 66% for BRCA1 and 27% for BRCA2 mutation carriers. Ovarian cancer in Ashkenazi kindreds has served as a model for the study of the histopathology of inherited ovarian cancers as well as for the study of risk reduction and screening among all women at inherited risk of ovarian cancer.

Genetic counselors: translating genomic science into clinical practice

In a time of emerging genetic tests and technologies, genetic counselors are faced with the challenge of translating complex genomic data into information that will aid their client's ability to learn about, understand, make, and cope with decisions relating to genetic diagnoses. The first of two companion articles in this issue examines the role of the genetic counselor, particularly in counseling individuals at risk for or diagnosed with breast cancer, in an era of high-tech health care and gene patents.

The Role of Estrogens in BRCA1/2 Mutation Carriers

Persons undergoing genetic testing for an inherited predisposition to cancer often raise questions about recommendations for follow-up care. Missing from current guidelines is consideration of the role of estrogens for BRCA1/BRCA2 mutation carriers. Potential implications of hormones for risk of cancer and effectiveness of risk-reduction strategies need to be considered in the design of comprehensive guidelines for high-risk women. Patients who are mutation carriers may ask questions about the use of oral contraceptives, hormone replacement, and utility of current screening modalities. Controversy exists, even when considering these issues for the general population, but become more imperative when considering young, unaffected women who carry an inherited genetic mutation making decisions that may have long-term health consequences. Many patients have considered estrogen ablation via prophylactic surgeries as risk-reduction interventions. This article reviews data regarding these issues, makes recommendations based on available information, and offers future perspectives for those identified at high risk for cancer because of genetic predisposition. Although questions remain regarding the potential implications of hormones for risk of cancer and effectiveness of risk-reduction strategies, all information should be considered when educating and caring for such patients.

Breast and ovarian cancer risks due to inherited mutations in BRCA1 and BRCA2

Risks of breast and ovarian cancer were determined for Ashkenazi Jewish women with inherited mutations in the tumor suppressor genes BRCA1 and BRCA2. We selected 1008 index cases, regardless of family history of cancer, and carried out molecular analysis across entire families. The lifetime risk of breast cancer among female mutation carriers was 82%, similar to risks in families with many cases. Risks appear to be increasing with time: Breast cancer risk by age 50 among mutation carriers born before 1940 was 24%, but among those born after 1940 it was 67%. Lifetime risks of ovarian cancer were 54% for BRCA1 and 23% for BRCA2 mutation carriers. Physical exercise and lack of obesity in adolescence were associated with significantly delayed breast cancer onset.

Genetic counselors: translating genomic science into clinical practice

In a time of emerging genetic tests and technologies, genetic counselors are faced with the challenge of translating complex genomic data into information that will aid their client's ability to learn about, understand, make, and cope with decisions relating to genetic diagnoses. The first of two companion articles in this issue examines the role of the genetic counselor, particularly in counseling individuals at risk for or diagnosed with breast cancer, in an era of high-tech health care and gene patents.

Long-Term Psychological Impact of Carrying a BRCA1/2 Mutation and Prophylactic Surgery: A 5-Year Follow-Up Study

Purpose: To explore long-term psychosocial consequences of carrying a BRCA1/2 mutation and to identify possible risk factors for long-term psychological distress.

Patients and Methods: Five years after genetic test disclosure, 65 female participants (23 carriers, 42 noncarriers) of our psychological follow-up study completed a questionnaire and 51 participants were interviewed. We assessed general and hereditary cancer-related distress, risk perception, openness to discuss the test result with relatives, body image and sexual functioning.

Results: Carriers did not differ from noncarriers on several distress measures and both groups showed a significant increase in anxiety and depression from 1 to 5 years follow-up. Carriers having undergone prophylactic surgery (21 of 23 carriers) had a less favorable body image than noncarriers and 70% reported changes in the sexual relationship. A major psychological benefit of prophylactic surgery was a reduction in the fear of developing cancer. Predictors of long-term distress were hereditary cancer-related distress at blood sampling, having young children, and having lost a relative to breast/ovarian cancer. Long-term distress was also associated with less open communication about the test result within the family, changes in relationships with relatives, doubting about the validity of the test result, and higher risk perception.

Conclusion: Our findings support the emerging consensus that genetic predisposition testing for BRCA1/2 does not pose major mental health risks, but our findings also show that the impact of prophylactic surgery on aspects such as body image and sexuality should not be underestimated, and that some women are at risk for high distress, and as a result, need more attentive care.

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?

Cancer incidence in relatives of a population-based set of cases of early-onset breast cancer with a known BRCA1 and BRCA2 mutation status

BACKGROUND

Relatives of breast cancer cases have an increased risk of the disease. The risk increases with increasing numbers and decreasing age of onset of affected relatives. In families with a BRCA1 or a BRCA2 mutation, individual carrier status predicts the risk of breast cancer. In relatives of cases where both BRCA1 and BRCA2 mutations are excluded, the risk remains undetermined.

METHODS

Standardized incidence ratios (SIRs) and cumulative cancer incidences were calculated for relatives of a population-based set of early-onset breast cancer index cases (younger than age 41 years) with a defined BRCA mutation status (n = 203).

RESULTS

In first-degree relatives (FDRs) of mutation-negative cases, breast cancer incidences (SIR = 2.3), prostate cancer incidences (SIR = 1.7), cervix cancer incidences (SIR = 3.3) and nonmelanoma skin cancer incidences (SIR = 2.8) were increased. The risks of breast cancer, prostate cancer and nonmelanoma skin cancer were further increased in FDRs of breast cancer cases younger than 36 years of age. In high-risk individuals with at least one relative with breast cancer apart from the index case, but no BRCA mutation in the family, breast cancer incidence was increased (SIR = 5.3); again the prostate cancer incidence was elevated (SIR = 2.5). The cumulative incidence of breast cancer at ages 50 and 70 years for FDRs of index cases without a BRCA mutation was 3.6% and 12.8%, respectively. Similarly, the cumulative incidence of breast cancer for high-risk women was 6.3% and 21.1% at ages 50 and 70 years, and that for FDRs of BRCA mutation carriers was 17.2% and 27.7% at the same ages.

CONCLUSION

The incidence of breast cancer is increased for FDRs of women with early-onset breast cancer irrespective of the BRCA status in the family. Risk increases with decreasing age and with increasing number of affected relatives. The incidences of prostate cancer, cervix cancer and nonmelanoma skin cancer are elevated for FDRs of early-onset breast cancer cases without a BRCA mutation, indicating a possible association between these cancers and early-onset breast cancer.

FANCF methylation contributes to chemoselectivity in ovarian cancer

A new model of ovarian cancer tumor progression implicates aberrant FANCF promoter methylation that is associated with gene silencing and disruption of the Fanconi-anemia-BRCA pathway. Disruption of the pathway occurs de novo in ovarian cancers and may contribute to selective sensitivity to platinum salts.