BRCA1 and BRCA2 mutations account for a large proportion of ovarian carcinoma cases

BACKGROUND

It is believed that BRCA1 and BRCA2 germline mutations account for the majority of hereditary ovarian carcinomas; however, to the authors' knowledge, there are scant data on the prevalence and spectrum of mutations, genotype/phenotype correlations, tumor histology, and family history characteristics. To address this gap, the authors conducted a population-based study of 232 incident epithelial ovarian carcinomas in the Tampa Bay area.

METHODS

Genetic testing for the BRCA1 and BRCA2 genes was performed through full sequencing and BRCA1 rearrangement testing.

RESULTS

Of 209 women with invasive ovarian carcinoma, 32 women (15.3%) had mutations in BRCA1 or BRCA2, including 20 BRCA1 mutations and 12 BRCA2 mutations. Of the BRCA2 mutations, 58% were outside the "ovarian cancer cluster region" (OCCR). Variants of uncertain significance were detected in 8.2% of women with invasive ovarian carcinoma. No mutations were identified in women with borderline or invasive mucinous tumors. Among the BRCA mutation-positive women, 63% had serous tumors. A family history of breast and/or ovarian carcinoma was reported in 65%, 75%, and 43.5% of relatives of BRCA1 carriers, BRCA2 carriers, and non-BRCA1/BRCA2 carriers, respectively.

CONCLUSIONS

The data from this study suggested that 1) previous studies may have underestimated the frequency of BRCA1 and BRCA2 mutations in ovarian carcinomas, especially outside the OCCR; 2) it may be reasonable to offer genetic counseling to any woman with an invasive, nonmucinous epithelial ovarian tumor; and 3) among patients with invasive ovarian carcinoma, family history is not sufficiently accurate to predict mutation status.

A Population-Based Study of Genes Previously Implicated in Breast Cancer

BACKGROUND

Population-based estimates of the risk of breast cancer associated with germline pathogenic variants in cancer-predisposition genes are critically needed for risk assessment and management in women with inherited pathogenic variants.

METHODS

In a population-based case-control study, we performed sequencing using a custom multigene amplicon-based panel to identify germline pathogenic variants in 28 cancer-predisposition genes among 32,247 women with breast cancer (case patients) and 32,544 unaffected women (controls) from population-based studies in the Cancer Risk Estimates Related to Susceptibility (CARRIERS) consortium. Associations between pathogenic variants in each gene and the risk of breast cancer were assessed.

RESULTS

Pathogenic variants in 12 established breast cancer-predisposition genes were detected in 5.03% of case patients and in 1.63% of controls. Pathogenic variants in BRCA1 and BRCA2 were associated with a high risk of breast cancer, with odds ratios of 7.62 (95% confidence interval [CI], 5.33 to 11.27) and 5.23 (95% CI, 4.09 to 6.77), respectively. Pathogenic variants in PALB2 were associated with a moderate risk (odds ratio, 3.83; 95% CI, 2.68 to 5.63). Pathogenic variants in BARD1, RAD51C, and RAD51D were associated with increased risks of estrogen receptor-negative breast cancer and triple-negative breast cancer, whereas pathogenic variants in ATM, CDH1, and CHEK2 were associated with an increased risk of estrogen receptor-positive breast cancer. Pathogenic variants in 16 candidate breast cancer-predisposition genes, including the c.657_661del5 founder pathogenic variant in NBN, were not associated with an increased risk of breast cancer.

CONCLUSIONS

This study provides estimates of the prevalence and risk of breast cancer associated with pathogenic variants in known breast cancer-predisposition genes in the U.S. population. These estimates can inform cancer testing and screening and improve clinical management strategies for women in the general population with inherited pathogenic variants in these genes. (Funded by the National Institutes of Health and the Breast Cancer Research Foundation.).

NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Breast and Ovarian, Version 2.2017

The NCCN Clinical Practice Guidelines in Oncology for Genetic/Familial High-Risk Assessment: Breast and Ovarian provide recommendations for genetic testing and counseling for hereditary cancer syndromes and risk management recommendations for patients who are diagnosed with a syndrome. Guidelines focus on syndromes associated with an increased risk of breast and/or ovarian cancer. The NCCN Genetic/Familial High-Risk Assessment: Breast and Ovarian panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. The NCCN Guidelines Insights summarize the panel's discussion and most recent recommendations regarding risk management for carriers of moderately penetrant genetic mutations associated with breast and/or ovarian cancer.

NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 1.2020

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic provide recommendations for genetic testing and counseling for hereditary cancer syndromes, and risk management recommendations for patients who are diagnosed with syndromes associated with an increased risk of these cancers. The NCCN panel meets at least annually to review comments, examine relevant new data, and reevaluate and update recommendations. These NCCN Guidelines Insights summarize the panel's discussion and most recent recommendations regarding criteria for high-penetrance genes associated with breast and ovarian cancer beyond BRCA1/2, pancreas screening and genes associated with pancreatic cancer, genetic testing for the purpose of systemic therapy decision-making, and testing for people with Ashkenazi Jewish ancestry.

Cancer Risks Associated With Germline PALB2 Pathogenic Variants: An International Study of 524 Families

PURPOSE

To estimate age-specific relative and absolute cancer risks of breast cancer and to estimate risks of ovarian, pancreatic, male breast, prostate, and colorectal cancers associated with germline PALB2 pathogenic variants (PVs) because these risks have not been extensively characterized.

METHODS

We analyzed data from 524 families with PALB2 PVs from 21 countries. Complex segregation analysis was used to estimate relative risks (RRs; relative to country-specific population incidences) and absolute risks of cancers. The models allowed for residual familial aggregation of breast and ovarian cancer and were adjusted for the family-specific ascertainment schemes.

RESULTS

We found associations between PALB2 PVs and risk of female breast cancer (RR, 7.18; 95% CI, 5.82 to 8.85; P = 6.5 × 10-76), ovarian cancer (RR, 2.91; 95% CI, 1.40 to 6.04; P = 4.1 × 10-3), pancreatic cancer (RR, 2.37; 95% CI, 1.24 to 4.50; P = 8.7 × 10-3), and male breast cancer (RR, 7.34; 95% CI, 1.28 to 42.18; P = 2.6 × 10-2). There was no evidence for increased risks of prostate or colorectal cancer. The breast cancer RRs declined with age (P for trend = 2.0 × 10-3). After adjusting for family ascertainment, breast cancer risk estimates on the basis of multiple case families were similar to the estimates from families ascertained through population-based studies (P for difference = .41). On the basis of the combined data, the estimated risks to age 80 years were 53% (95% CI, 44% to 63%) for female breast cancer, 5% (95% CI, 2% to 10%) for ovarian cancer, 2%-3% (95% CI females, 1% to 4%; 95% CI males, 2% to 5%) for pancreatic cancer, and 1% (95% CI, 0.2% to 5%) for male breast cancer.

CONCLUSION

These results confirm PALB2 as a major breast cancer susceptibility gene and establish substantial associations between germline PALB2 PVs and ovarian, pancreatic, and male breast cancers. These findings will facilitate incorporation of PALB2 into risk prediction models and optimize the clinical cancer risk management of PALB2 PV carriers.

Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic or likely pathogenic variants associated with increased risk of breast, ovarian, and pancreatic cancer and recommended approaches to genetic testing/counseling and management strategies in individuals with these pathogenic or likely pathogenic variants. This manuscript focuses on cancer risk and risk management for BRCA-related breast/ovarian cancer syndrome and Li-Fraumeni syndrome. Carriers of a BRCA1/2 pathogenic or likely pathogenic variant have an excessive risk for both breast and ovarian cancer that warrants consideration of more intensive screening and preventive strategies. There is also evidence that risks of prostate cancer and pancreatic cancer are elevated in these carriers. Li-Fraumeni syndrome is a highly penetrant cancer syndrome associated with a high lifetime risk for cancer, including soft tissue sarcomas, osteosarcomas, premenopausal breast cancer, colon cancer, gastric cancer, adrenocortical carcinoma, and brain tumors.

Racial disparities in BRCA testing and cancer risk management across a population-based sample of young breast cancer survivors

BACKGROUND

Breast cancer (BC) disparities may widen with genomic advances. The authors compared non-Hispanic white (NHW), black, and Hispanic BC survivors for 1) cancer risk-management practices among BRCA carriers and 2) provider discussion and receipt of genetic testing.

METHODS

A population-based sample of NHW, black, and Hispanic women who had been diagnosed with invasive BC at age 50 years or younger from 2009 to 2012 were recruited through the state cancer registry. Multiple logistic regression was used to compare cancer risk-management practices in BRCA carriers and associations of demographic and clinical variables with provider discussion and receipt of testing.

RESULTS

Of 1622 participants, 159 of 440 (36.1%) black women, 579 of 897 (64.5%) NHW women, 58 of 117 (49.6%) Spanish-speaking Hispanic women, and 116 of 168 (69%) English-speaking Hispanic women underwent BRCA testing, of whom 90 had a pathogenic BRCA mutation identified. Among BRCA carriers, the rates of risk-reducing mastectomy and risk-reducing salpingo-oophorectomy were significantly lower among black women compared with Hispanic and NHW women after controlling for clinical and demographic variables (P = .025 and P = .008, respectively). Compared with NHW women, discussion of genetic testing with a provider was 16 times less likely among black women (P < .0001) and nearly 2 times less likely among Spanish-speaking Hispanic women (P = .04) after controlling for clinical and sociodemographic factors.

CONCLUSIONS

The current results suggest that the rates of risk-reducing salpingo-oophorectomy are lower among black BRCA carriers compared with their Hispanic and NHW counterparts, which is concerning because benefits from genetic testing arise from cancer risk-management practice options. Furthermore, lower BRCA testing rates among blacks may partially be because of a lower likelihood of provider discussion. Future studies are needed to improve cancer risk identification and management practices across all populations to prevent the widening of disparities. Cancer 2017;123:2497-05. © 2017 American Cancer Society.

Long-term ovarian cancer survival associated with mutation in BRCA1 or BRCA2

BACKGROUND

Studies have suggested that the 5-year survival of women with ovarian cancer and a BRCA1 or BRCA2 mutation is better than expected. We sought to evaluate the impact of carrying a BRCA1 or BRCA2 mutation on long-term survival of women after a diagnosis of invasive ovarian cancer.

METHODS

One thousand six hundred twenty-six unselected women diagnosed with invasive ovarian cancer in Ontario, Canada, or in Tampa, Florida, between 1995 and 2004 were followed for a mean of 6.9 years (range = 0.3 to 15.7 years). Mutation screening for BRCA1 and BRCA2 revealed mutations in 218 women (13.4%). Left-truncated survival analysis was conducted to estimate ovarian cancer-specific survival at various time points after diagnosis for women with and without mutations.

RESULTS

In the 3-year period after diagnosis, the presence of a BRCA1 or BRCA2 mutation was associated with a better prognosis (adjusted hazard ratio = 0.68, 95% confidence interval [CI] = 0.48 to 0.98; P = .03), but at 10 years after diagnosis, the hazard ratio was 1.00 (95% CI = 0.83 to 1.22; P = .90). Among women with serous ovarian cancers, 27.4% of women who were BRCA1 mutation carriers, 27.7% of women who were BRCA2 carriers, and 27.1% of women who were noncarriers were alive at 12 years past diagnosis.

CONCLUSION

For women with invasive ovarian cancer, the short-term survival advantage of carrying a BRCA1 or BRCA2 mutation does not lead to a long-term survival benefit.

Genetic/Familial High-Risk Assessment: Breast and Ovarian, Version 2.2015

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast and Ovarian provide recommendations for genetic testing and counseling and risk assessment and management for hereditary cancer syndromes. Guidelines focus on syndromes associated with an increased risk of breast and/or ovarian cancer and are intended to assist with clinical and shared decision-making. These NCCN Guidelines Insights summarize major discussion points of the 2015 NCCN Genetic/Familial High-Risk Assessment: Breast and Ovarian panel meeting. Major discussion topics this year included multigene testing, risk management recommendations for less common genetic mutations, and salpingectomy for ovarian cancer risk reduction. The panel also discussed revisions to genetic testing criteria that take into account ovarian cancer histology and personal history of pancreatic cancer.

Bilateral Oophorectomy and Breast Cancer Risk in BRCA1 and BRCA2 Mutation Carriers

Background

Whether oophorectomy reduces breast cancer risk among BRCA mutation carriers is a matter of debate. We undertook a prospective analysis of bilateral oophorectomy and breast cancer risk in BRCA mutation carriers.

Methods

Subjects had no history of cancer, had both breasts intact, and had information on oophorectomy status (n = 3722). Women were followed until breast cancer diagnosis, prophylactic bilateral mastectomy, or death. A Cox regression model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer associated with oophorectomy (coded as a time-dependent variable). All statistical tests were two-sided.

Results

Over a mean follow-up of 5.6 years, 350 new breast cancers were diagnosed. Among women with a BRCA1 or BRCA2 mutation, oophorectomy was not associated with breast cancer risk compared with women who did not undergo an oophorectomy. The age-adjusted hazard ratio associated with oophorectomy was 0.96 (95% CI = 0.73 to 1.26, P = 76) for BRCA1 and was 0.65 (95% CI = 0.37 to 1.16, P = 14) for BRCA2 mutation carriers. In stratified analyses, the effect of oophorectomy was statistically significant for breast cancer in BRCA2 mutation carriers diagnosed prior to age 50 years (age-adjusted HR = 0.18, 95% CI = 0.05 to 0.63, P = 007). Oophorectomy was not associated with risk of breast cancer prior to age 50 years among BRCA1 mutation carriers (age-adjusted HR = 0.79, 95% CI = 0.55 to 1.13, P = 51).

Conclusions

Findings from this large prospective study support a role of oophorectomy for the prevention of premenopausal breast cancer in BRCA2, but not BRCA1 mutation carriers. These findings warrant further evaluation.

Overall Mortality After Diagnosis of Breast Cancer in Men vs Women

Importance

Survival differences between male and female patients with breast cancer have been reported, but the underlying factors associated with the disparity have not been fully studied. This understanding is fundamental to developing strategies for cancer treatment and survivorship care.

Objective

To compare mortality between male and female patients with breast cancer and quantitatively evaluate the factors associated with sex-based disparity in mortality.

Design, Setting, and Participants

This large, nationwide, registry-based cohort study used the National Cancer Database to identify and obtain data on patients who received a breast cancer diagnosis between January 1, 2004, and December 31, 2014. After exclusions, the final study population comprised 1 816 733 patients. Statistical analyses were conducted from September 1, 2018, to January 15, 2019.

Main Outcomes and Measures

The primary outcome was overall survival. Secondary outcomes were 3-year and 5-year mortality. Mortality differences were evaluated by Kaplan-Meier analysis. The roles of race/ethnicity, clinical characteristics, treatments, and access-to-care factors in the association between sex and mortality were estimated by nested Cox proportional hazards regression models with adjustment for age.

Results

In total, 16 025 male (mean [SD] age, 63.3 [13.0] years) and 1 800 708 female (mean [SD] age, 59.9 [13.3] years) patients with breast cancer were included in the study. Compared with female patients, male patients had higher mortality across all stages. For men, the overall survival rate was 45.8% (95% CI, 49.5-54.0; P < .001), the 3-year rate was 86.4% (95% CI, 85.9-87.0; P < .001), and the 5-year rate was 77.6% (95% CI, 76.8-78.3; P < .001). For women, the overall survival rate was 60.4% (95% CI, 58.7-62.0; P < .001), the 3-year rate was 91.7% (95% CI, 91.7-91.8; P < .001), and the 5-year rate was 86.4% (95% CI, 86.4-86.5; P < .001). Overall, clinical characteristics and undertreatments were associated with a 63.3% excess mortality rate for male patients. A higher proportion of excess deaths in men were explained by these factors in the first 3 years after breast cancer diagnosis (66.0%) and in all patients with early-stage cancer (30.5% for stage I and 13.6% for stage II). However, sex remained a significant factor associated with overall mortality (adjusted hazard ratio [HR], 1.19; 95% CI, 1.16-1.23) as well as mortality at 3-year (adjusted HR, 1.15; 95% CI, 1.10-1.21) and 5-year (adjusted HR, 1.19; 95% CI, 1.14-1.23) analyses, even after adjustment for clinical characteristics, treatment factors, age, race/ethnicity, and access to care.

Conclusions and Relevance

This study found that mortality after cancer diagnosis was higher among male patients with breast cancer compared with their female counterparts. Such disparity appeared to persist after accounting for clinical characteristics, treatment factors, and access to care, suggesting that other factors (particularly additional biological attributes, treatment compliance, and lifestyle factors) should be identified to help in eliminating this disparity.

International trends in the uptake of cancer risk reduction strategies in women with a BRCA1 or BRCA2 mutation

BACKGROUND

Women with a BRCA1 or BRCA2 mutation face high risks of breast and ovarian cancer. In the current study, we report on uptake of cancer screening and risk-reduction options in a cohort of BRCA mutation carriers from ten countries over two time periods (1995 to 2008 and 2009 to 2017).

METHODS

Eligible subjects were identified from an international database of female BRCA mutation carriers and included women from 59 centres from ten countries. Subjects completed a questionnaire at the time of genetic testing, which included past use of cancer prevention options and screening tests. Biennial follow-up questionnaires were administered.

RESULTS

Six-thousand two-hundred and twenty-three women were followed for a mean of 7.5 years. The mean age at last follow-up was 52.1 years (27-96 years) and 42.3% of the women had a prior diagnosis of breast cancer. In all, 27.8% had a prophylactic bilateral mastectomy and  64.7% had a BSO. Screening with breast MRI increased from 70% before 2009 to 81% at or after 2009. There were significant differences in uptake of all options by country.

CONCLUSION

For women who received genetic testing more recently, uptake of prophylactic mastectomy and breast MRI is significantly higher than those who received genetic testing more than 10 years ago. However, uptake of both BSO and breast MRI is not optimal, and interventions to increase uptake are needed.

Systematic review and meta-analysis of ovarian cancers: estimation of microsatellite-high frequency and characterization of mismatch repair deficient tumor histology

PURPOSE

A meta-analytic approach was used to estimate the frequency of: (a) microsatellite instability-high (MSI-H) phenotype in unselected ovarian cancers and (b) various histologic subtypes of mismatch repair (MMR)-deficient epithelial ovarian cancers.

METHODS

A systematic search of the Medline electronic database was conducted to identify articles published between January 1, 1966, and December 31, 2007, that examined MMR deficiency in ovarian cancers. Data were extracted on the study population, sample size, MSI-H frequency, and histology of MMR-deficient ovarian tumors.

RESULTS

The pooled proportion of MSI-H ovarian cancers was 0.12 [95% confidence interval (CI), 0.08-0.17] from 18 studies with 977 cases. The proportion of histologic subtypes in the pooled analysis from 15 studies with 159 cases was serous at 0.32 (95% CI, 0.20-0.44), mucinous at 0.19 (95% CI, 0.12-0.27), endometrioid at 0.29 (95% CI, 0.22-0.36), clear cell at 0.18 (95% CI, 0.09-0.28), and mixed at 0.24 (95% CI, 0.07-0.47). There was significant heterogeneity between studies.

CONCLUSIONS

The frequency of the MSI-H phenotype in unselected ovarian cancers approximates 12%. MMR-deficient ovarian cancers also seem to be characterized by an overrepresentation of nonserous histologic subtypes. Knowledge of histologic subtype may aid clinicians in identifying the relatively large proportion of ovarian cancers due to MMR defects; such knowledge has potential implications for medical management.

A high frequency of BRCA mutations in young black women with breast cancer residing in Florida

BACKGROUND

Black women are disproportionately affected with triple-negative breast cancer and have relatively poor survival. To the authors' knowledge, it is not known to what extent differences in the clinical presentation of breast cancer between non-Hispanic white women and black women can be accounted for by the presence of mutations in the BRCA1 and BRCA2 genes. The authors sought to evaluate the frequency of BRCA pathogenic variants in a population-based sample of young black women with breast cancer.

METHODS

Black women diagnosed with invasive breast cancer at age ≤50 years from 2009 to 2012 were recruited to the study through the Florida Cancer Registry. Participants underwent genetic counseling, completed a study questionnaire, and consented to release of their medical records. Saliva specimens were collected for BRCA sequencing and large rearrangement testing through multiplex ligation-dependent probe amplification.

RESULTS

A DNA sample was evaluated for 396 women, 49 of whom (12.4%) had a mutation in BRCA1 or BRCA2. Eight recurrent mutations accounted for 49% of all pathogenic variants.

CONCLUSIONS

To the authors' knowledge, the prevalence of BRCA mutations among the Florida-based sample of young black women with breast cancer in the current study exceeds that previously reported for non-Hispanic white women. It is appropriate to recommend BRCA testing in all young black women with invasive breast cancer.

Is uterine papillary serous adenocarcinoma a manifestation of the hereditary breast-ovarian cancer syndrome?

BACKGROUND

Uterine papillary serous carcinoma (UPSC) shares common pathologic, genetic, and clinical features with other serous cancers of müllerian origin. The most common histologic type of ovarian tumor associated with BRCA mutations is papillary serous. Because of these histologic similarities, we postulated that, in some cases, UPSC may be a manifestation of a field defect in BRCA1 carriers, which also includes ovarian carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma.

METHODS

Fifty-six living patients with UPSC were contacted through their treating physicians and agreed to a family history interview and to provide a blood specimen for BRCA testing. The protein truncation test was used to detect mutations in exons 10 and 11 of BRCA1 and in exon 11 of BRCA2. The presence of four common mutations was assessed by PCR-based specific assays.

RESULTS

A high proportion of patients had a past history of breast cancer (11%) or a first-degree relative with breast cancer (29%). Four patients were from families with site-specific hereditary breast cancer. However, there was no clear example of the hereditary breast-ovarian cancer syndrome, and none of the 56 patients was found to carry a BRCA1 or BRCA2 mutation.

CONCLUSIONS

BRCA mutations do not appear to predispose to UPSC and this type of cancer does not appear to be a manifestation of the classical hereditary breast-ovarian cancer syndrome. The observed association between UPSC and breast cancer may be due to the presence of mutations in other cancer predisposing genes.

Long-Term Psychosocial Functioning in Women with Bilateral Prophylactic Mastectomy: Does Preservation of the Nipple-Areolar Complex Make a Difference?

INTRODUCTION

Nipple-sparing prophylactic mastectomy (PM) is an option for women at high-risk for breast cancer, and may offer better cosmetic results than a skin-sparing PM where the nipple-areolar complex (NAC) is removed. However, there may be residual breast cancer risk due to the maintained NAC. It is unclear if sparing the NAC with PM impacts on psychosocial functioning, including cancer-related distress and body image after PM.

METHODS

This was a cross-sectional survey study of women who had undergone bilateral PM (no previous breast cancer) recruited through surgical or cancer genetics clinics. All women completed standardized questionnaires assessing cancer-related distress, anxiety, depression, satisfaction with decision, decision regret, and health-related quality of life related to breast surgery. Outcomes were compared between women with nipple-areola-sparing PM (NAC-PM) and skin-sparing PM (SS-PM).

RESULTS

Overall, 137 women completed the study; 53 (39%) had NAC-PM and 84 (61%) had SS-PM. The mean age of the study population was 41.5 years [standard deviation (SD) 8.8] and the mean time between PM and questionnaire completion was 50 months (SD 31). On the BREAST-Q, we found that women with NAC-PM had significantly higher levels of satisfaction with breasts (p = 0.01), satisfaction with outcome (p = 0.02), and sexual well-being (p < 0.001) compared with SS-PM. No statistically significant differences in total cancer-related distress (p = 0.89), anxiety (p = 0.86), or depression (p = 0.93) were observed between the two groups.

CONCLUSIONS

Overall, women with NAC-PM had better body image and sexual functioning compared with women with SS-PM, while both groups had comparable levels of cancer-related distress and perception of breast cancer risk.

A review of the clinical relevance of mismatch-repair deficiency in ovarian cancer

Ovarian cancer ranks fifth in both cancer incidence and mortality among women in the United States. Defects in the mismatch-repair (MMR) pathway that arise through genetic and/or epigenetic mechanisms may be important etiologically in a reasonable proportion of ovarian cancers. Genetic mechanisms of MMR dysfunction include germline and somatic mutations in the MMR proteins. Germline mutations cause hereditary nonpolyposis colorectal cancer (HNPCC), which is the third most common cause of inherited ovarian cancer after BRCA1 and BRCA2 mutations. An epigenetic mechanism known to cause inactivation of the MMR system is promoter hypermethylation of 1 of the MMR genes, mutL homolog 1 (MLH1). Various laboratory methods, in addition to clinical and histopathologic criteria, can be used to identify MMR-deficient ovarian cancers. Such methods include microsatellite instability analysis, immunohistochemistry, MLH1 promoter hypermethylation testing, and germline mutation analysis. In this review, the authors describe the existing literature regarding the molecular, clinical, and histologic characteristics of MMR-deficient ovarian cancers along with the possible effect on survival and treatment response. By further defining the profile of MMR-deficient ovarian cancers and their associated etiologic mechanisms, there may be a greater potential to distinguish between those of hereditary and sporadic etiology. The ability to make such distinctions may be of diagnostic, prognostic, and therapeutic utility.

Panel-based testing for inherited colorectal cancer: a descriptive study of clinical testing performed by a US laboratory

Next-generation sequencing enables testing for multiple genes simultaneously (‘panel-based testing’) as opposed to sequential testing for one inherited condition at a time (‘syndrome-based testing’). This study presents results from patients who underwent hereditary colorectal cancer (CRC) panel-based testing (‘ColoNext™’). De-identified data from a clinical testing laboratory were used to calculate (1) frequencies for patient demographic, clinical, and family history variables and (2) rates of pathogenic mutations and variants of uncertain significance (VUS). The proportion of individuals with a pathogenic mutation who met national syndrome-based testing criteria was also determined. Of 586 patients, a pathogenic mutation was identified in 10.4%, while 20.1% had at least one VUS. After removing eight patients with CHEK2 mutations and 11 MUTYH heterozygotes, the percentage of patients with ‘actionable’ mutations that would clearly alter cancer screening recommendations per national guidelines decreased to 7.2%. Of 42 patients with an ‘actionable’ result, 30 (71%) clearly met established syndrome-based testing guidelines. This descriptive study is among the first to report on a large clinical series of patients undergoing panel-based testing for inherited CRC. Results are discussed in the context of benefits and concerns that have been raised about panel-based testing implementation.

Conflict of interest

Cristi Radford and Jill Dolinsky are full-time employees for the commercial laboratory Ambry Genetics, which performs ColoNext™ testing. Elizabeth Chao is a paid consultant for Ambry. Deborah Cragun, Meghan Caldwell, and Tuya Pal report no potential conflicts of interest. Specifically, they are not employed by Ambry, and they did not receive any financial or other incentives from Ambry.

Increased risk for nonmedullary thyroid cancer in the first degree relatives of prevalent cases of nonmedullary thyroid cancer: a hospital-based study

The genetic basis for nonmedullary forms of thyroid cancer (NMTC) is less well established than that of medullary thyroid cancer. However, epidemiological and family studies suggest that a proportion of NMTC may be due to inherited predisposition. To estimate the familial risk of thyroid cancer, we conducted a hospital-based case-control study at the Princess Margaret Hospital in Toronto, Ontario, Canada, and at 2 university hospitals in Montréal, Québec, Canada. We obtained pedigrees from 339 unselected patients diagnosed with NMTC and from 319 unaffected ethnically matched controls. Family histories of cancer were obtained from the cases and controls for 3292 first degree relatives of cases and controls. Seventeen cases (5.0%) and 2 controls (0.6%) reported at least one first degree relative with thyroid cancer. In relatives of patients with thyroid cancer, the incidence of any type of cancer (including NMTC) was 38% higher than in relatives of controls (incidence rate ratio, 1.4; 95% confidence interval, 1.1-1.7). The relative risk for thyroid cancer was 10-fold higher in relatives of cancer patients than in controls (incidence rate ratio, 10.3; 95% confidence interval, 2.2-47.6). Our findings suggest that hereditary or other familial factors are important in a small proportion of NMTC. Molecular studies are needed to determine the genetic basis of cancer susceptibility in these families.

Factors associated with genetic counseling and BRCA testing in a population-based sample of young Black women with breast cancer

Concerns about the potential for genomic advances to increase health disparities have been raised. Thus, it is important to assess referral and uptake of genetic counseling (GC) and testing in minority populations at high risk for hereditary breast and ovarian cancer (HBOC). Black women diagnosed with invasive breast cancer ≤age 50 in 2009-2012 were recruited through the Florida State Cancer Registry 6-18 months following diagnosis and completed a baseline questionnaire. Summary statistics, Chi-square tests, and path modeling were conducted to examine which demographic and clinical variables were associated with referral and access to genetic services. Of the 440 participants, all met national criteria for GC, yet only 224 (51 %) were referred for or received GC and/or HBOC testing. Variables most strongly associated with healthcare provider referral for GC included having a college education (OR 2.1), diagnosis at or below age 45 (OR 2.0), and triple negative tumor receptor status (OR 1.7). The strongest association with receipt of GC and/or HBOC testing was healthcare provider referral (OR 7.9), followed by private health insurance at diagnosis (OR 2.8), and household income greater than $35,000 in the year prior to diagnosis (OR 2.0). Study findings suggest efforts are needed to improve genetic services access among a population-based sample of high-risk Black women. These results indicate that socioeconomic factors and physician referral patterns contribute to disparities in access to genetic services within this underserved minority population.

Mismatch repair gene defects contribute to the genetic basis of double primary cancers of the colorectum and endometrium

Hereditary non-polyposis colorectal cancer (HNPCC) is a dominantly inherited cancer syndrome caused by germline defects of mismatch repair (MMR) genes. Endometrial cancer is the most common extracolonic neoplasm in HNPCC and is the primary clinical manifestation of the syndrome in some families. The cumulative incidence of endometrial cancer among HNPCC mutation carriers is high, estimated to be from 22 to 43%. We hypothesized that women with double primary cancers of the colorectum and endometrium are likely to be members of HNPCC families. In order to determine how frequently HNPCC manifests in the context of double primary cancers, we examined alterations of two MMR genes, hMSH2 and hMLH1, in 40 unrelated women affected with double primary cancers. These cases were identified using hospital-based and population-based cancer registries in Ontario, Canada. MMR gene mutations were screened by single-strand conformation polymorphism analysis and confirmed by direct sequencing. Eighteen percent (seven of 40) were found to harbor mutations of one of the two MMR genes. Analysis of colorectal and/or endometrial tumors of mutation-negative probands found microsatellite instability in seven of 20 cases. Six of seven mutation-positive probands had strong family histories suggestive of HNPCC. First degree relatives of mutation-positive probands had a very high relative risk (RR) of colorectal cancer (RR = 8.1, CI 3. 5-15.9) and endometrial cancer (RR = 23.8, CI 6.4-61.0). The relative risk of mutation-negative cases was 2.8 (CI 1.7-4.5) for colorectal cancer and 5.4 (CI 2.0-11.7) for endometrial cancer. We recommend that all double primary patients with cancers at these sites should have a genetic evaluation, including molecular analysis for HNPCC where appropriate.

Timing of oral contraceptive use and the risk of breast cancer in BRCA1 mutation carriers

It is not clear if early oral contraceptive use increases the risk of breast cancer among young women with a breast cancer susceptibility gene 1 (BRCA1) mutation. Given the benefit of oral contraceptives for the prevention of ovarian cancer, estimating age-specific risk ratios for oral contraceptive use and breast cancer is important. We conducted a case-control study of 2,492 matched pairs of women with a deleterious BRCA1 mutation. Breast cancer cases and unaffected controls were matched on year of birth and country of residence. Detailed information about oral contraceptive use was collected from a routinely administered questionnaire. Conditional logistic regression was used to estimate the odds ratios (OR) and 95 % confidence intervals (CI) for the association between oral contraceptive and breast cancer, by age at first use and by age at diagnosis. Among BRCA1 mutation carriers, oral contraceptive use was significantly associated with an increased risk of breast cancer for women who started the pill prior to age 20 (OR 1.45; 95 % CI 1.20-1.75; P = 0.0001) and possibly between ages 20 and 25 as well (OR 1.19; 95 % CI 0.99-1.42; P = 0.06). The effect was limited to breast cancers diagnosed before age 40 (OR 1.40; 95 % CI 1.14-1.70; P = 0.001); the risk of early-onset breast cancer increased by 11 % with each additional year of pill use when initiated prior to age 20 (OR 1.11; 95 % CI 1.03-1.20; P = 0.008). There was no observed increase for women diagnosed at or after the age of 40 (OR 0.97; 95 % CI 0.79-1.20; P = 0.81). Oral contraceptive use before age 25 increases the risk of early-onset breast cancer among women with a BRCA1 mutation and the risk increases with duration of use. Caution should be taken when advising women with a BRCA1 mutation to take an oral contraceptive prior to age 25.