Age-specific incidence rates for breast cancer in carriers of BRCA1 mutations from Norway

Breast cancer risk after age 60 among BRCA1 and BRCA2 mutation carriers

PURPOSE

It is not known whether the risk of breast cancer among BRCA1 and BRCA2 mutation carriers after age 60 is high enough to justify intensive screening or prophylactic surgery. Thus, we conducted a prospective analysis of breast cancer risk in BRCA1 and BRCA2 mutation carriers from age 60 until age 80.

METHODS

Subjects had no history of cancer and both breasts intact at age 60 (n = 699). Women were followed until a breast cancer diagnosis, prophylactic bilateral mastectomy or death. We calculated the annual cancer rate and cumulative incidence of breast cancer (invasive and in situ) from age 60 to age 80. We assessed the associations between hormone replacement therapy, family history of breast cancer and bilateral oophorectomy and breast cancer risk.

RESULTS

Over a mean follow-up of 7.9 years, 61 invasive and 20 in situ breast cancers were diagnosed in the cohort. The mean annual rate of invasive breast cancer was 1.8% for BRCA1 mutation carriers and 1.7% for BRCA2 mutation carriers. The cumulative risk of invasive breast cancer from age 60 to 80 was 20.1% for women with a BRCA1 mutation and was 17.3% for women with a BRCA2 mutation. Hormone replacement therapy, family history and oophorectomy were not associated with breast cancer risk.

CONCLUSIONS

Findings from this large prospective study indicate that the risk of developing breast cancer remains high after age 60 in both BRCA1 and BRCA2 mutation carriers. These findings warrant further evaluation of the role of breast cancer screening in older mutation carriers.

Causes for Frequent Pathogenic BRCA1 Variants Include Low Penetrance in Fertile Ages, Recurrent De-Novo Mutations and Genetic Drift

Background: We have previously demonstrated that the Norwegian frequent pathogenic BRCA1 (path_BRCA1) variants are caused by genetic drift and recurrent de-novo mutations. We here examined the penetrance of frequent path_BRCA1 variants in fertile ages as a surrogate marker for fitness. Material and methods: We conducted an observational prospective study of penetrance for cancer in Norwegian female carriers of frequent path_BRCA1 variants, and compared our observed results to penetrance of infrequent path_BRCA1 variants and to average penetrance of path_BRCA1 variants reported by others. Results: The cumulative risk for breast cancer at 45 years in carriers of frequent path_BRCA1 variants was 20% (94% confidence interval 10⁻30%), compared to 35% (95% confidence interval 22⁻48%) in carriers of infrequent path_BRCA1 variants (p = 0.02), and to the 35% (confidence interval 32⁻39%) average for path_BRCA1 carriers reported by others (p = 0.0001). Discussion and conclusion: Carriers of the most frequent Norwegian path_BRCA1 variants had low incidence of cancer in fertile ages, indicating a low selective disadvantage. This, together with the variant locations being hotspots for de novo mutations and subject to genetic drift, as previously described, may have caused their high prevalence today. Besides being of theoretical interest to explain the phenomenon that a few path_BRCA1 variants are frequent, the later onset of breast cancer associated with the most frequent path_BRCA1 variants may be of interest for carriers who have to decide if and when to select prophylactic mastectomy.

Age-specific risks of incident, contralateral and ipsilateral breast cancer among 1776 Polish BRCA1 mutation carriers

PURPOSE

Women with an inherited germline BRCA1 mutation have a high lifetime risk of developing breast cancer. We have previously shown that, among BRCA mutation carriers, incidence rates of breast cancer vary by country of residence.

METHODS

In the current study, we prospectively calculated the cumulative and annual incidence rates of incident breast cancer, contralateral breast cancer and ipsilateral breast cancer recurrence among BRCA1 mutation carriers in Poland. Study subjects comprised a cohort of 1776 Polish women with a BRCA1 mutation who had no prior diagnosis of breast or ovarian cancer at the time of enrollment, the women were followed with a biennial follow-up by questionnaire. Women were followed for an average of 6.1 years (range 0.0-18.2) and 191 new breast cancer cases were diagnosed.

RESULTS

The cumulative incidence of breast cancer to age 70 was 52%. The annual risk of breast cancer was estimated at 1.78%; the maximum annual risk was observed between the ages of 30 and 65. Among the 941 women with a prior diagnosis of breast cancer, 106 women developed a contralateral breast cancer. The 20-year cumulative incidence of contralateral breast cancer was 31% and the annual rate of contralateral breast cancer was 1.96%. There were 11 recurrences among the 215 women with breast cancer (ipsilateral breast cancers). The cumulative incidence at 20 years was 17% and the annual rate of an ipsilateral recurrence was 1.03%.

CONCLUSION

Our findings confirm the high annual rates of early-onset incident, contralateral and recurrent breast cancer among Polish BRCA1 mutation carriers. These risk estimates are important in the context of the clinical management of unaffected women as well as in the treatment of newly diagnosed primary breast cancers and can also be used as the basis for the planning of prevention trials.

Cancer risk and survival in path_MMR carriers by gene and gender up to 75 years of age: a report from the Prospective Lynch Syndrome Database

BACKGROUND

Most patients with path_MMR gene variants (Lynch syndrome (LS)) now survive both their first and subsequent cancers, resulting in a growing number of older patients with LS for whom limited information exists with respect to cancer risk and survival.

OBJECTIVE AND DESIGN

This observational, international, multicentre study aimed to determine prospectively observed incidences of cancers and survival in path_MMR carriers up to 75 years of age.

RESULTS

3119 patients were followed for a total of 24 475 years. Cumulative incidences at 75 years (risks) for colorectal cancer were 46%, 43% and 15% in path_MLH1, path_MSH2 and path_MSH6 carriers; for endometrial cancer 43%, 57% and 46%; for ovarian cancer 10%, 17% and 13%; for upper gastrointestinal (gastric, duodenal, bile duct or pancreatic) cancers 21%, 10% and 7%; for urinary tract cancers 8%, 25% and 11%; for prostate cancer 17%, 32% and 18%; and for brain tumours 1%, 5% and 1%, respectively. Ovarian cancer occurred mainly premenopausally. By contrast, upper gastrointestinal, urinary tract and prostate cancers occurred predominantly at older ages. Overall 5-year survival for prostate cancer was 100%, urinary bladder 93%, ureter 85%, duodenum 67%, stomach 61%, bile duct 29%, brain 22% and pancreas 0%. Path_PMS2 carriers had lower risk for cancer.

CONCLUSION

Carriers of different path_MMR variants exhibit distinct patterns of cancer risk and survival as they age. Risk estimates for counselling and planning of surveillance and treatment should be tailored to each patient's age, gender and path_MMR variant. We have updated our open-access website www.lscarisk.org to facilitate this.

Preferences for breast cancer risk reduction among BRCA1/BRCA2 mutation carriers: a discrete-choice experiment

Purpose

Unaffected women who carry BRCA1 or BRCA2 mutations face difficult choices about reducing their breast cancer risk. Understanding their treatment preferences could help us improve patient counseling and inform drug trials. The objective was to explore preferences for various risk-reducing options among women with germline BRCA1/2 mutations using a discrete-choice experiment survey and to compare expressed preferences with actual behaviors.

Methods

A discrete-choice experiment survey was designed wherein women choose between hypothetical treatments to reduce breast cancer risk. The hypothetical treatments were characterized by the extent of breast cancer risk reduction, treatment duration, impact on fertility, hormone levels, risk of uterine cancer, and ease and mode of administration. Data were analyzed using a random-parameters logit model. Women were also asked to express their preference between surgical and chemoprevention options and to report on their actual risk-reduction actions. Women aged 25–55 years with germline BRCA1/2 mutations who were unaffected with breast or ovarian cancer were recruited through research registries at five clinics and a patient advocacy group.

Results

Between January 2015 and March 2016, 622 women completed the survey. Breast cancer risk reduction was the most important consideration expressed, followed by maintaining fertility. Among the subset of women who wished to have children in future, the ability to maintain fertility was the most important factor, followed by the extent of risk reduction. Many more women said they would take a chemoprevention drug than had actually taken chemoprevention.

Conclusions

Women with BRCA1/2 mutations indicated strong preferences for breast cancer risk reduction and maintaining fertility. The expressed desire to have a safe chemoprevention drug available to them was not met by current chemoprevention options.

Electronic supplementary material

The online version of this article (doi:10.1007/s10549-017-4332-3) contains supplementary material, which is available to authorized users.

Identifying Needs: a Qualitative Study of women's Experiences Regarding Rapid Genetic Testing for Hereditary Breast and Ovarian Cancer in the DNA BONus Study

Genetic testing for hereditary breast and ovarian cancer is increasingly being offered in newly diagnosed breast and ovarian cancer patients. This genetic information may influence treatment decisions. However, there are some concerns that genetic testing offered in an already vulnerable situation might be an extra burden to these women. The aim of this study was to explore the experiences of women who had been offered and accepted genetic testing when newly diagnosed with breast or ovarian cancer. Four semi-structured focus-group interviews were conducted with 17 women recruited from a Norwegian multicenter study. The material was condensed, and conventional qualitative analysis was used to identify patterns in the participants’ descriptions. Three core themes were identified: 1) being “beside oneself” 2) altruism and ethical dilemmas 3) the need for support and counselling to assist the decision process. The present study indicates that women who are offered genetic testing when newly diagnosed with breast or ovarian cancer want a consultation with a health professional. Personalized support and counselling might empower women to improve their ability to manage and comprehend this overwhelming situation, and find meaning in this experience.

Ten modifiers of BRCA1 penetrance validated in a Norwegian series

Background

Common genetic variants have been shown to modify BRCA1 penetrance. The aim of this study was to validate these reports in a special cohort of Norwegian BRCA1 mutation carriers that were selected for their extreme age of onset of disease.

Methods

The ten variants rs13387042, rs3803662, rs8170, rs9397435, rs700518, rs10046, rs3834129, rs1045485, rs2363956 and rs16942 were selected to be tested on samples from our biobank. We selected female BRCA1 mutation carriers having had a diagnosis of breast or ovarian cancer below 40 years of age (young cancer group, N = 40), and mutation carriers having had neither breast nor ovarian cancer above 60 years of age (i.e., old no cancer group, N = 38). Relative risks and odd ratios of belonging to the young cancer versus old no cancer groups were calculated as a function of having or not having the SNPs in question.

Results

Five of the ten variants were found to be significantly associated with early onset cancer. Some of the variation between our results and those previously reported may be ascribed to stochastic effects in our limited number of patient studies, and/or genetic drift in linkage disequilibrium in the genetically isolated Norwegian population. This is in accordance with the understanding that the SNPs are markers in linkage disequilibrium with their respective disease-causing genetic variants, and that this may vary between different populations.

Conclusions

The results confirmed associations previously reported, with the notion that the degree of association may differ between other populations, which must be considered when discussing the clinical use of the associations described.

Electronic supplementary material

The online version of this article (doi:10.1186/s13053-015-0035-0) contains supplementary material, which is available to authorized users.

Tumour characteristics and survival in familial breast cancer prospectively diagnosed by annual mammography

Women from breast cancer families without a demonstrable BRCA1/2 mutation were subjected to annual mammography from age 30 years onwards. One-hundred and ninety-eight patients were diagnosed prospectively with invasive breast cancer and followed for a total of 1513 years. Overall 10-year survival was 88 %. Together with our previous report that women in such kindreds had about twice the population risk of breast cancer, the combined conclusion was that the overall chances of developing breast cancer causing death within 10 years before 50 years of age was 1 % or less when subjected to annual mammography and current treatment. These are empirical prospective observations which may be used for genetic counselling. The majority (160/194 = 84 %) of patients had ER+ and/or low grade tumours with 92 % 10-year survival. One minor group of the patients had ER- tumours, another small group had high grade tumours with nodal spread, both groups were associated with worse prognosis, but the two groups were not mutually associated.

The clinical utility of genetic testing in breast cancer kindreds: a prospective study in families without a demonstrable BRCA mutation

We report prospectively observed risk for breast cancer in breast cancer kindreds without a demonstrable BRCA1/2 mutation. According to family history, the optimal available member(s) of each breast cancer kindred attending our clinic was tested for BRCA mutations. Women in families without a demonstrable BRCA mutation were subjected to annual mammography. BRCA mutations were demonstrated in 496/2,118 (23 %) breast cancer kindreds. In families without a demonstrable BRCA mutation, a total of 3,161 healthy women aged 25-59 years were prospectively followed for 24,808 observation years. Sixty-four cancers were observed, compared to 34.0 expected (p < 0.01), arriving at a 7.9 % cumulative risk at age 60 compared to 4.0 % in the population [relative risk (RR) = 2.0]. Women with one mother or sister affected ≤50 years and with no other close relatives with breast cancer did not have increased risk (0 cancers observed and 0.6 expected at age 40, 11 cancers observed and 7.9 expected at age 60, p > 0.05). Excluding these, cumulative risk at 60 years was 8.8 % (RR = 2.2). The highest cumulative risk at 60 years was 11.4 %, found in families with two cases ≤55 years (RR = 2.8). In breast cancer kindreds without a demonstrable BRCA mutation, the risk for breast cancer in female first degree relatives was about twice the risk in the general population. Women with one early affected relative only did not have increased risk for early onset breast cancer, while those with more than one young affected relative had close to three times population risk.

Identification, Evaluation, and Treatment of Patients with Hereditary Cancer Risk within the United States

Recognizing the importance of identifying patients at high risk for inherited cancer predisposition, the United States Preventive Services Task Force (USPSTF) has outlined specific family history patterns associated with an increased risk for BRCA mutations. However, national data indicate a need to facilitate the ability of primary care providers to appropriately identify high risk patients. Once a patient is identified as high risk, it is necessary for the patient to undergo a detailed genetics evaluation to generate a differential diagnosis, determine a cost-effective genetic testing strategy, and interpret results of testing. With identification of inherited predisposition, risk management strategies in line with national guidelines can be implemented to improve patient outcomes through cancer risk reduction and early detection. As use of genetic testing increasingly impacts patient outcomes, the role of primary care providers in the identification and care of individuals at high risk for hereditary cancer becomes even more important. Nevertheless it should be acknowledged that primary care providers face many competing demands and challenges to identify high risk patients. Therefore initiatives which promote multidisciplinary and coordinated care, potentially through academic-community partnerships, may provide an opportunity to enhance care of these patients.

Clinical implications of genetic testing for BRCA1 and BRCA2 mutations in Austria

The objective of this study was to describe the experience of genetic testing in Austrian women with a BRCA1 or BRCA2 mutation in terms of preventive measures taken and incident cancers diagnosed. We collected clinical information on 246 Austrian women with a BRCA1 or BRCA2 mutation tested between 1995 and 2012 and followed 182 of them for an average of 6.5 years. Of the 90 women who were cancer-free at baseline, 21.4% underwent preventive bilateral mastectomy, 46.1% had preventive bilateral salpingo-oophorectomy, and 1 took tamoxifen; 58.8% of the at-risk women underwent at least one screening breast magnetic resonance imaging (MRI). Of the 85 women with breast cancer, 69.4% had a unilateral mastectomy or lumpectomy and 30.6% had a contralateral mastectomy. In the follow-up period, 14 new invasive breast cancers (6 first primary and 8 contralateral), 1 ductal carcinoma in situ case, 2 incident ovarian cancer cases, and 1 peritoneal cancer were diagnosed. In Austria, the majority of healthy women with a BRCA1 or BRCA2 mutation opt for preventive oophorectomy and MRI screening to manage their breast cancer risk; few have preventive mastectomy or take tamoxifen.

Genetic risk assessments in individuals at high risk for inherited breast cancer in the breast oncology care setting

BACKGROUND

It has become increasingly common to consider BRCA mutation status when determining optimal cancer risk management and treatment options in order to improve patient outcomes. Knowledge about the risk for hereditary cancer at or as close as possible to the time of diagnosis allows patients access to the most risk reduction options available.

METHODS

This paper illustrates the role of genetic risk assessment for hereditary breast cancer, using hereditary breast and ovarian cancer (HBOC) syndrome as a model due to germline mutations in the BRCA1 and BRCA2. Specifically, the value of genetic counseling and testing for HBOC across the cancer prevention and control continuum is outlined as it pertains to breast cancer.

RESULTS

In recognition of the importance of risk assessment for hereditary breast cancer, leading health professional organizations have developed specific guidelines and recommendations to providers for identification of women at increased risk for carrying a BRCA mutation.

CONCLUSIONS

Institutional efforts specific to genetic counseling and testing have resulted in the implementation of a model driven by physician recommendation as a referral system for high-risk breast cancer patients. Establishing an infrastructure to support research, education, and outreach initiatives focused on BRCA genetic counseling and testing will provide information that can improve the delivery of cancer genetics services.

Survival of patients with BRCA1-associated breast cancer diagnosed in an MRI-based surveillance program

We report the 5- and 10-year survival rate of women diagnosed with breast cancer in the context of an annual MRI-based surveillance program. In 2001, as part of a national initiative, women in Norway with a BRCA1 mutation were offered annual screening with breast MRI in addition to mammography. 802 women with a BRCA1 mutation were screened one or more times and followed for a mean of 4.2 years. As of December 2011, 68 of 802 women in the screening program were diagnosed with DCIS or invasive breast cancer (8.5 %), including eight prevalent, 50 incident screen-detected and eight interval cancers. Two latent cancers were detected at prophylactic mastectomy. Sixty-three of the cancers were invasive and five were in situ. The mean tumour size was 1.4 cm (range 0.2-4.5 cm), and 85 % of the patients were node-negative. Ten of the 68 patients died of cancer in the follow-up period. The 5-year breast cancer-specific survival for women with cancer was 75 % (95 % CI 56-86 %) and the 10-year survival was 69 % (95 % CI: 48-83 %). The 5-year survival for women with Stage 1 breast cancer was 82 % compared to 98 % in the population. The 5- and 10-year survival of women with a BRCA1-associated breast cancer detected in a national MRI-based screening program in BRCA1 mutation carriers Norway was less than anticipated. The benefit of annual MRI surveillance on reducing breast cancer mortality in BRCA1 mutation carriers remains to be proven.