Cancer risks in Jewish male BRCA1 and BRCA2 mutation carriers

Prostate cancer risk, screening and management in patients with germline BRCA1/2 mutations

Mutations in the BRCA1 and BRCA2 tumour suppressor genes are associated with prostate cancer risk; however, optimal screening protocols for individuals with these mutations have been a subject of debate. Several prospective studies of prostate cancer incidence and screening among BRCA1/2 mutation carriers have indicated at least a twofold to fourfold increase in prostate cancer risk among carriers of BRCA2 mutations compared with the general population. Moreover, BRCA2 mutations are associated with more aggressive, high-grade disease characteristics at diagnosis, more aggressive clinical behaviour and greater prostate cancer-specific mortality. The risk for BRCA1 mutations seems to be attenuated compared with BRCA2. Prostate-specific antigen (PSA) measurement or prostate magnetic resonance imaging (MRI) alone is an imperfect indicator of clinically significant prostate cancer; therefore, BRCA1/2 mutation carriers might benefit from refined risk stratification strategies. However, the long-term impact of prostate cancer screening is unknown, and the optimal management of BRCA1/2 carriers with prostate cancer has not been defined. Whether timely localized therapy can improve overall survival in the screened population is uncertain. Long-term results of prospective studies are awaited to confirm the optimal screening strategies and benefits of prostate cancer screening among BRCA1/2 mutation carriers, and whether these approaches ultimately have a positive impact on survival and quality of life in these patients.

BRCA1 and BRCA2 pathogenic variants and prostate cancer risk: systematic review and meta-analysis

BACKGROUND

BRCA1 and BRCA2 pathogenic variants (PVs) are associated with prostate cancer (PCa) risk, but a wide range of relative risks (RRs) has been reported.

METHODS

We systematically searched PubMed, Embase, MEDLINE and Cochrane Library in June 2021 for studies that estimated PCa RRs for male BRCA1/2 carriers, with no time or language restrictions. The literature search identified 27 studies (BRCA1: n = 20, BRCA2: n = 21).

RESULTS

The heterogeneity between the published estimates was high (BRCA1: I2 = 30%, BRCA2: I2 = 83%); this could partly be explained by selection for age, family history or aggressive disease, and study-level differences in ethnicity composition, use of historical controls, and location of PVs within BRCA2. The pooled RRs were 2.08 (95% CI 1.38-3.12) for Ashkenazi Jewish BRCA2 carriers, 4.35 (95% CI 3.50-5.41) for non-Ashkenazi European ancestry BRCA2 carriers, and 1.18 (95% CI 0.95-1.47) for BRCA1 carriers. At ages <65 years, the RRs were 7.14 (95% CI 5.33-9.56) for non-Ashkenazi European ancestry BRCA2 and 1.78 (95% CI 1.09-2.91) for BRCA1 carriers.

CONCLUSIONS

These PCa risk estimates will assist in guiding clinical management. The study-level subgroup analyses indicate that risks may be modified by age and ethnicity, and for BRCA2 carriers by PV location within the gene, which may guide future risk-estimation studies.

Trends in male breast cancer mortality: a global overview

OBJECTIVES

Recent trends in male breast cancer have been inadequately studied. We updated mortality trends in selected countries and regions worldwide using most recent available data and we predicted figures for 2020.

METHODS

We extracted official death certification data for male breast cancer and population estimates from the WHO and the Pan American Health Organization databases, from 2000 to 2017. We computed age-standardized (world population) death rates for selected countries and regions worldwide. We used joinpoint regression analysis to identify significant changes in trends and to predict death numbers and rates for 2020.

RESULTS

In 2015-2017, Central-Eastern Europe had a rate of 2.85/1 000 000, and Russia of 2.22, ranking among the highest. North-Western and Southern Europe, the European Union as a whole and the USA showed rates ranging between 1.5 and 2.0. Lower rates were observed in most Latin American countries, with values below 1.35/1 000 000, in Australia, 1.22, and Japan, 0.58. Between 2000-2004 and 2015-2017, age-adjusted death rates decreased between 10 and 40% in North-Western Europe, Russia, and the USA, and between 1.5 and 25% in the other areas under study, except Latin America (+0.8%). Except for Central-Eastern Europe, predicted rates for 2020 were favourable.

CONCLUSION

Advancements in management are likely the main drivers of the favourable trends in male breast cancer death rates over the last decades. Delayed diagnosis and limited access to effective care explain the higher mortality in some areas.

Penetrance of male breast cancer susceptibility genes: a systematic review

PURPOSE

Several male breast cancer (MBC) susceptibility genes have been identified, but the MBC risk for individuals with a pathogenic variant in each of these genes (i.e., penetrance) remains unclear. We conducted a systematic review of studies reporting the penetrance of MBC susceptibility genes to better summarize current estimates of penetrance.

METHODS

A search query was developed to identify MBC-related papers indexed in PubMed/MEDLINE. A validated natural language processing method was applied to identify papers reporting penetrance estimates. These penetrance studies' bibliographies were reviewed to ensure comprehensiveness. We accessed the potential ascertainment bias for each enrolled study.

RESULTS

Fifteen penetrance studies were identified from 12,182 abstracts, covering five purported MBC susceptibility genes: ATM, BRCA1, BRCA2, CHEK2, and PALB2. Cohort (n = 6, 40%) and case-control (n = 5, 33%) studies were the two most common study designs, followed by family-based (n = 3, 20%), and a kin-cohort study (n = 1, 7%). Seven of the 15 studies (47%) adjusted for ascertainment adequately and therefore the MBC risks reported by these seven studies can be considered applicable to the general population. Based on these seven studies, we found pathogenic variants in ATM, BRCA2, CHEK2 c.1100delC, and PALB2 show an increased risk for MBC. The association between BRCA1 and MBC was not statistically significant.

CONCLUSION

This work supports the conclusion that pathogenic variants in ATM, BRCA2, CHEK2 c.1100delC, and PALB2 increase the risk of MBC, whereas pathogenic variants in BRCA1 may not be associated with increased MBC risk.

Characterization of the Cancer Spectrum in Men With Germline BRCA1 and BRCA2 Pathogenic Variants: Results From the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

Importance

The limited data on cancer phenotypes in men with germline BRCA1 and BRCA2 pathogenic variants (PVs) have hampered the development of evidence-based recommendations for early cancer detection and risk reduction in this population.

Objective

To compare the cancer spectrum and frequencies between male BRCA1 and BRCA2 PV carriers.

Design, Setting, and Participants

Retrospective cohort study of 6902 men, including 3651 BRCA1 and 3251 BRCA2 PV carriers, older than 18 years recruited from cancer genetics clinics from 1966 to 2017 by 53 study groups in 33 countries worldwide collaborating through the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Clinical data and pathologic characteristics were collected.

Main Outcomes and Measures

BRCA1/2 status was the outcome in a logistic regression, and cancer diagnoses were the independent predictors. All odds ratios (ORs) were adjusted for age, country of origin, and calendar year of the first interview.

Results

Among the 6902 men in the study (median [range] age, 51.6 [18-100] years), 1634 cancers were diagnosed in 1376 men (19.9%), the majority (922 of 1,376 [67%]) being BRCA2 PV carriers. Being affected by any cancer was associated with a higher probability of being a BRCA2, rather than a BRCA1, PV carrier (OR, 3.23; 95% CI, 2.81-3.70; P < .001), as well as developing 2 (OR, 7.97; 95% CI, 5.47-11.60; P < .001) and 3 (OR, 19.60; 95% CI, 4.64-82.89; P < .001) primary tumors. A higher frequency of breast (OR, 5.47; 95% CI, 4.06-7.37; P < .001) and prostate (OR, 1.39; 95% CI, 1.09-1.78; P = .008) cancers was associated with a higher probability of being a BRCA2 PV carrier. Among cancers other than breast and prostate, pancreatic cancer was associated with a higher probability (OR, 3.00; 95% CI, 1.55-5.81; P = .001) and colorectal cancer with a lower probability (OR, 0.47; 95% CI, 0.29-0.78; P = .003) of being a BRCA2 PV carrier.

Conclusions and Relevance

Significant differences in the cancer spectrum were observed in male BRCA2, compared with BRCA1, PV carriers. These data may inform future recommendations for surveillance of BRCA1/2-associated cancers and guide future prospective studies for estimating cancer risks in men with BRCA1/2 PVs.

Association of Genomic Domains in BRCA1 and BRCA2 with Prostate Cancer Risk and Aggressiveness

Pathogenic sequence variants (PSV) in BRCA1 or BRCA2 (BRCA1/2) are associated with increased risk and severity of prostate cancer. We evaluated whether PSVs in BRCA1/2 were associated with risk of overall prostate cancer or high grade (Gleason 8+) prostate cancer using an international sample of 65 BRCA1 and 171 BRCA2 male PSV carriers with prostate cancer, and 3,388 BRCA1 and 2,880 BRCA2 male PSV carriers without prostate cancer. PSVs in the 3' region of BRCA2 (c.7914+) were significantly associated with elevated risk of prostate cancer compared with reference bin c.1001-c.7913 [HR = 1.78; 95% confidence interval (CI), 1.25-2.52; P = 0.001], as well as elevated risk of Gleason 8+ prostate cancer (HR = 3.11; 95% CI, 1.63-5.95; P = 0.001). c.756-c.1000 was also associated with elevated prostate cancer risk (HR = 2.83; 95% CI, 1.71-4.68; P = 0.00004) and elevated risk of Gleason 8+ prostate cancer (HR = 4.95; 95% CI, 2.12-11.54; P = 0.0002). No genotype-phenotype associations were detected for PSVs in BRCA1. These results demonstrate that specific BRCA2 PSVs may be associated with elevated risk of developing aggressive prostate cancer. SIGNIFICANCE: Aggressive prostate cancer risk in BRCA2 mutation carriers may vary according to the specific BRCA2 mutation inherited by the at-risk individual.

Prostate Cancer Risks for Male BRCA1 and BRCA2 Mutation Carriers: A Prospective Cohort Study

BACKGROUND

BRCA1 and BRCA2 mutations have been associated with prostate cancer (PCa) risk but a wide range of risk estimates have been reported that are based on retrospective studies.

OBJECTIVE

To estimate relative and absolute PCa risks associated with BRCA1/2 mutations and to assess risk modification by age, family history, and mutation location.

DESIGN, SETTING, AND PARTICIPANTS

This was a prospective cohort study of male BRCA1 (n = 376) and BRCA2 carriers (n = 447) identified in clinical genetics centres in the UK and Ireland (median follow-up 5.9 and 5.3 yr, respectively).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Standardised incidence/mortality ratios (SIRs/SMRs) relative to population incidences or mortality rates, absolute risks, and hazard ratios (HRs) were estimated using cohort and survival analysis methods.

RESULTS AND LIMITATIONS

Sixteen BRCA1 and 26 BRCA2 carriers were diagnosed with PCa during follow-up. BRCA2 carriers had an SIR of 4.45 (95% confidence interval [CI] 2.99-6.61) and absolute PCa risk of 27% (95% CI 17-41%) and 60% (95% CI 43-78%) by ages 75 and 85 yr, respectively. For BRCA1 carriers, the overall SIR was 2.35 (95% CI 1.43-3.88); the corresponding SIR at age <65 yr was 3.57 (95% CI 1.68-7.58). However, the BRCA1 SIR varied between 0.74 and 2.83 in sensitivity analyses to assess potential screening effects. PCa risk for BRCA2 carriers increased with family history (HR per affected relative 1.68, 95% CI 0.99-2.85). BRCA2 mutations in the region bounded by positions c.2831 and c.6401 were associated with an SIR of 2.46 (95% CI 1.07-5.64) compared to population incidences, corresponding to lower PCa risk (HR 0.37, 95% CI 0.14-0.96) than for mutations outside the region. BRCA2 carriers had a stronger association with Gleason score ≥7 (SIR 5.07, 95% CI 3.20-8.02) than Gleason score ≤6 PCa (SIR 3.03, 95% CI 1.24-7.44), and a higher risk of death from PCa (SMR 3.85, 95% CI 1.44-10.3). Limitations include potential screening effects for these known mutation carriers; however, the BRCA2 results were robust to multiple sensitivity analyses.

CONCLUSIONS

The results substantiate PCa risk patterns indicated by retrospective analyses for BRCA2 carriers, including further evidence of association with aggressive PCa, and give some support for a weaker association in BRCA1 carriers.

PATIENT SUMMARY

In this study we followed unaffected men known to carry mutations in the BRCA1 and BRCA2 genes to investigate whether they are at higher risk of developing prostate cancer compared to the general population. We found that carriers of BRCA2 mutations have a high risk of developing prostate cancer, particularly more aggressive prostate cancer, and that this risk varies by family history of prostate cancer and the location of the mutation within the gene.

Family history of cancer, Ashkenazi Jewish ancestry, and pancreatic cancer risk

Background

Individuals with a family history of cancer may be at increased risk of pancreatic cancer. Ashkenazi Jewish (AJ) individuals carry increased risk for pancreatic cancer and other cancer types.

Methods

We examined the association between family history of cancer, AJ heritage, and incident pancreatic cancer in 49 410 male participants of the prospective Health Professionals Follow-up Study. Hazard ratios (HRs) were estimated using multivariable-adjusted Cox proportional hazards models.

Results

During 1.1 million person-years (1986–2016), 452 participants developed pancreatic cancer. Increased risk of pancreatic cancer was observed in individuals with a family history of pancreatic (HR, 2.79; 95% confidence interval [CI], 1.28–6.07) or breast cancer (HR, 1.40; 95% CI, 1.01–1.94). There was a trend towards higher risk of pancreatic cancer in relation to a family history of colorectal cancer (HR, 1.21; 95% CI, 0.95–1.55) or AJ heritage (HR, 1.29; 95% CI, 0.94–1.77). The risk was highly elevated among AJ men with a family history of breast or colorectal cancer (HR, 2.61 [95% CI, 1.41–4.82] and 1.92 [95% CI, 1.05–3.49], respectively).

Conclusion

Family history of pancreatic cancer was associated with increased risk of this malignancy. Family history of breast or colorectal cancer was associated with the increased risk among AJ men.

Abnormal Findings Detected by Multi-modality Breast Imaging and Biopsy Results in a High-risk Clinic

BACKGROUND

High-risk BRCA mutation carriers are offered a surveillance scheme aimed at early detection of breast cancer. Although the efficacy of this scheme in breast cancer detection is well-established, the rate of breast cancer diagnosis of radiologically suspicious lesions and the effect of this screening scheme on breast cancer grade and stage are less well-defined.

PATIENTS AND METHODS

Female BRCA1 and BRCA2 mutation carriers who were cancer-free at the beginning of follow-up at the Meirav High-risk Clinic, Sheba Medical Center, were eligible. Radiological imaging data (mammography, ultrasound, magnetic resonance imaging, Breast Imaging Reporting and Data System scores), and histopathologic data on breast biopsies were retrieved.

RESULTS

Overall, 1055 women participated in the study; 760 (72%) were Ashkenazim, 661 (62.6%) were BRCA1 mutation carriers, the mean age at first visit was 44.1 ± 11.8 years, and there was a mean follow-up of 6.2 years. All participants underwent 6641 breast imaging tests: 2613 magnetic resonance imagings, 2662 breast ultrasounds, and 1366 mammograms. Overall, 295 biopsies were performed on 254 women: 82 (27%) biopsies on 79 women were diagnosed with breast cancer, including ductal carcinoma in situ: invasive breast cancer was diagnosed in 58 (70.7%), of whom 36 (62% of invasive cancer) were grade 3, and all but 10 were stage 1 to 2. Benign findings were noted in 213 biopsies performed on 175 women, with fibrocystic disease (n = 134; 62.9%) or fibroadenoma (n = 60; 28.16%) most commonly diagnosed.

CONCLUSIONS

Adherence to a breast cancer surveillance scheme enables breast cancer detection at an early stage but at advanced grade. Most biopsies (72%) performed in this high-risk clinic are benign.