The association of race/ethnicity in male breast cancer survival within similar comorbidity cohorts.

BACKGROUND: Concomitant disease is associated with poor breast cancer survival in women and is more prevalent in racial/ethnic minority groups than individuals who are non-Hispanic White. The purpose of this study was to determine if race/ethnicity is associated with survival among men with breast cancer when stratifying analyses by level of comorbidity. METHODS: We used the California Cancer Registry to identify 1730 cases of men and 259,828 cases of women with breast cancer and documented Charlson Comorbidity Index (CCI). Kaplan-Meier survival and Cox regression analyses were used to compare breast cancer-specific survival and risk of mortality for African American/Black, Hispanic, and Asian/Pacific Islander men with White women and White men. RESULTS: When compared with White women, Black men with a CCI of 0 (hazard ratio [HR], 3.09; 95% CI, 1.10-1.16) and a CCI of 2+, (HR, 2.51; 95% CI, 1.42-4.42) had an increased risk of mortality when compared with White women. When compared with White men, African American men with a CCI of 0 (HR, 2.36; 95% CI, 1.45-3.85) and 2+ (HR, 2.44; 95% CI, 1.26-4.74) had an increased unadjusted risk of mortality, but these disparities were neutralized when controlling for sociodemographic and clinical factors. CONCLUSIONS: Black men with both low and high levels of concomitant disease have an increased risk of mortality when compared with both White men and women, but demographic and clinical factors are contributors to this disparity.

Common founder BRCA2 pathogenic variants and breast cancer characteristics in Ethiopian Jews.

PURPOSE: BRCA1/2 founder pathogenic variants (PVs) occur in various populations, but data on the mutational spectrum in Africans are limited. We examined BRCA1/2 PVs in breast cancer patients of Ethiopian Jewish (EJ) origin. METHODS: We retrospectively analyzed BRCA1/2 test results and clinical features of EJ breast cancer patients from seven medical institutions. We obtained heterozygote carrier rates in affected individuals from the laboratories of the largest Israeli HMO (Clalit). Population carrier frequency was determined in EJ controls. RESULTS: We identified three recurrent BRCA2 PVs in 11 EJ breast cancer patients (9 females, 2 males): c.7579delG, c.5159C > A, and c.9693delA. Only c.5159C > A was previously reported in Africans. In women, mean age at diagnosis was 35.7y; 8/9 were diagnosed with advanced disease. All tumors were invasive, 4/9 were triple negative. Only 3/11 carriers had relevant family history. Carrier rate in high-risk breast cancer patients was 11% (3/28; 95%CI [2.3%, 28.2%]). Combined carrier rate among controls was 1.8% (5/280; 95%CI [0.6%, 4.1%]). CONCLUSION: EJs harbor 3 recurrent BRCA2 PVs presenting with relatively severe breast cancer morbidity. Combined with the high BRCA2 carrier rate in the EJ population, these findings merit increasing awareness in this community and suggest that a culturally adapted population screening approach may be warranted.

A Prospective Population-Based Study of Cardiovascular Disease Mortality following Treatment for Breast Cancer among Men in the United States, 2000-2019.

Male breast cancer is rare but its incidence and mortality are increasing in the United States, with racial/ethnic disparities in survival reported. There is limited evidence for cardiotoxicity of cancer treatment among men with breast cancer. We evaluated the relation between breast cancer treatment and cardiovascular disease (CVD) mortality among men and investigated the salient roles that race/ethnicity play on this relation. Data were from 5216 men with breast cancer aged ≥ 40 years from the Surveillance, Epidemiology, and End Results program who were diagnosed from 2000 to 2019 and underwent surgery. Competing risk models were used to estimate hazards ratios (HR) and 95% confidence intervals (CI). During a median follow-up of 5.6 years, 1914 deaths occurred with 25% attributable to CVD. In multivariable-adjusted models, men who received chemotherapy had elevated risk for CVD (HR: 1.55, 95%CI: 1.18-2.04). This risk was higher among Hispanic men (HR: 3.96, 95%CI: 1.31-12.02) than non-Hispanic Black and non-Hispanic White men. There was no significant association between radiotherapy and CVD deaths. In this population-based study, treatment with chemotherapy was associated with elevated risk of CVD mortality in men with breast cancer. Racial/ethnic disparities in the association of chemotherapy and CVD mortality were observed.

Breast Cancer Survival Among Males by Race, Ethnicity, Age, Geographic Region, and Stage - United States, 2007-2016.

Breast cancer among males in the United States is rare; approximately 2,300 new cases and 500 associated deaths were reported in 2017, accounting for approximately 1% of all breast cancers.* Risk for male breast cancer increases with increasing age (1), and compared with women, men receive diagnoses later in life and often at a later stage of disease (1). Gradual improvement in breast cancer survival from 1976-1985 to 1996-2005 has been more evident for women than for men (1). Studies examining survival differences among female breast cancer patients observed that non-Hispanic White (White) females had a higher survival than non-Hispanic Black (Black) females (2), but because of the rarity of breast cancer among males, few studies have examined survival differences by race or other factors such as age, stage, and geographic region. CDC's National Program of Cancer Registries (NPCR)† data were used to examine relative survival of males with breast cancer diagnosed during 2007-2016 by race/ethnicity, age group, stage at diagnosis, and U.S. Census region. Among males who received a diagnosis of breast cancer during 2007-2016, 1-year relative survival was 96.1%, and 5-year relative survival was 84.7%. Among characteristics examined, relative survival varied most by stage at diagnosis: the 5-year relative survival for males was higher for cancers diagnosed at localized stage (98.7%) than for those diagnosed at distant stage (25.9%). Evaluation of 1-year and 5-year relative survival among males with breast cancer might help guide health care decisions regarding early detection of male breast cancer and establishing programs to support men at high risk for breast cancer and male breast cancer survivors.

Effects of marital status on breast cancer survival by age, race, and hormone receptor status: A population-based Study.

INTRODUCTION: It remains unclear whether marital status could affect the breast cancer-caused special survival (BCSS) of patients with breast cancer. Therefore, we sought to explore the influence of demographic and pathological factors on prognosis of patients with breast cancer. MATERIALS AND METHODS: We selected patients meeting the eligibility criteria from the Surveillance, Epidemiology, and End Results (SEER) cancer registry program. We assessed the effect of marital status on overall survival (OS) and BCSS using Kaplan-Meier curve and multivariate Cox proportional hazards regression. RESULTS: Compared with divorced/separated/widowed (DSW) patients, the married (AHR 0.7483, 95% CI: 0.729-0.7682, P < 0.001) and single patients had better BCSS (AHR 0.9096, 95% CI: 0.8796-0.9406, P < 0.001). Married patients kept better prognosis among all age subgroups, while the better BCSS of single patients occurred only in groups older than 35 years. As for race and hormone receptor status (HRs), the better BCSS of single patients was only observed in white race (AHR 0.881, 95% CI: 0.8457-0.9177, P < 0.001) and patients with ER+/PR + status (AHR 0.8844, 95% CI: 0.8393-0.932, P < 0.001). CONCLUSION: Our findings demonstrated that married and single patients with breast cancer had better prognosis than their DSW counterparts. Age, race, and HRs could affect the correlation between marital status and BCSS.

Comparison of Breast Cancer Molecular Features and Survival by African and European Ancestry in The Cancer Genome Atlas.

Importance: African Americans have the highest breast cancer mortality rate. Although racial difference in the distribution of intrinsic subtypes of breast cancer is known, it is unclear if there are other inherent genomic differences that contribute to the survival disparities. Objectives: To investigate racial differences in breast cancer molecular features and survival and to estimate the heritability of breast cancer subtypes. Design, Setting, and Participants: Among a convenience cohort of patients with invasive breast cancer, breast tumor and matched normal tissue sample data (as of September 18, 2015) were obtained from The Cancer Genome Atlas. Main Outcomes and Measures: Breast cancer­free interval, tumor molecular features, and genetic variants. Results: Participants were 930 patients with breast cancer, including 154 black patients of African ancestry (mean [SD] age at diagnosis, 55.66 [13.01] years; 98.1% [n = 151] female) and 776 white patients of European ancestry (mean [SD] age at diagnosis, 59.51 [13.11] years; 99.0% [n = 768] female). Compared with white patients, black patients had a worse breast cancer-free interval (hazard ratio, HR=1.67; 95% CI, 1.02-2.74; P = .043). They had a higher likelihood of basal-like (odds ratio, 3.80; 95% CI, 2.46-5.87; P < .001) and human epidermal growth factor receptor 2 (ERBB2 [formerly HER2])­enriched (odds ratio, 2.22; 95% CI, 1.10-4.47; P = .027) breast cancer subtypes, with the Luminal A subtype as the reference. Blacks had more TP53 mutations and fewer PIK3CA mutations than whites. While most molecular differences were eliminated after adjusting for intrinsic subtype, the study found 16 DNA methylation probes, 4 DNA copy number segments, 1 protein, and 142 genes that were differentially expressed, with the gene-based signature having an excellent capacity for distinguishing breast tumors from black vs white patients (cross-validation C index, 0.878). Using germline genotypes, the heritability of breast cancer subtypes (basal vs nonbasal) was estimated to be 0.436 (P = 1.5 × 10−14). The estrogen receptor­positive polygenic risk score built from 89 known susceptibility variants was higher in blacks than in whites (difference, 0.24; P = 2.3 × 10−5), while the estrogen receptor­negative polygenic risk score was much higher in blacks than in whites (difference, 0.48; P = 2.8 × 10−11). Conclusions and Relevance: On the molecular level, after adjusting for intrinsic subtype frequency differences, this study found a modest number of genomic differences but a significant clinical survival outcome difference between blacks and whites in The Cancer Genome Atlas data set. Moreover, more than 40% of breast cancer subtype frequency differences could be explained by genetic variants. These data could form the basis for the development of molecular targeted therapies to improve clinical outcomes for the specific subtypes of breast cancers that disproportionately affect black women. Findings also indicate that personalized risk assessment and optimal treatment could reduce deaths from aggressive breast cancers for black women.

Cancer Risk Information Sharing: The Experience of Individuals Receiving Genetic Counseling for BRCA1/2 Mutations.

Genetic counseling and testing for familial cancer is a unique context for the communication of risk information in the family. This study utilized a theoretical framework based on the family systems perspective to understand intrafamilial cancer risk communication patterns in the Ashkenazi Jewish population. Individuals (n = 120) at an elevated risk for BRCA1/2 mutations were included. Change in communication patterns over time was assessed using McNemar tests. Associations with communication patterns were assessed with multivariable logistic regression. Overall, the proportion of participants encouraged by others significantly (p < .001) increased from before to after genetic counseling. A higher proportion of participants were encouraged by female family members compared with male family members. Participants who were older, had no personal history of cancer, and had a higher cancer risk perception were more likely to be encouraged by others for genetic testing. Participant's intent to encourage family members for genetic testing from before counseling to after receipt of genetic test results decreased by 16.7%. Participants who had no personal history of cancer and had informative test results for a BRCA1/2 mutation were more likely to encourage other family members for genetic testing. In addition, qualitative findings suggested that closeness among family members, concern for family, especially future generations, and cognizance about cancer risk facilitate information sharing and encouragement for genetic testing. Our findings indicate that intrafamilial cancer risk communication varies with the structure of family relationships and that genetic counseling can play an important role in improving intrafamilial cancer risk communication.

Features of triple-negative breast cancer: Analysis of 38,813 cases from the national cancer database.

The aim of this study was to determine the features of triple-negative breast cancer (TNBC) using a large national database. TNBC is known to be an aggressive subtype, but national epidemiologic data are sparse. All patients with invasive breast cancer and known molecular subtype diagnosed in 2010 to 2011 were identified from the National Cancer Data Base (NCDB). Patients with and without TNBC were compared with respect to their sociodemographic and clinicopathologic features. TNBC was present in 38,628 of 295,801 (13%) female patients compared to 185 of 3136 (6%) male patients (P < 0.001). The incidence of TNBC varied by region from 10.8% in New England to 15.8% in the east south central US (P < 0.001), as well as by race with the highest rates in African-Americans (23.7%), and lowest in Filipino patients (8.9%). The incidence of TNBC also varied by histology, accounting for 76% of metaplastic cancers, but only 2% of infiltrating lobular carcinomas. TNBCs were significantly larger than non-TNBC (mean 2.8 cm vs 2.1 cm, P < 0.001), and more TNBC were poorly differentiated compared to other subtypes (79.7% vs 25.8%, P < 0.001). On univariate analysis, TNBC was no more likely than non-TNBC to have node-positive disease (32.0% vs 31.7%, respectively, P = 0.218) but in a multivariable analysis controlling for tumor size and grade, TNBC was associated with significantly less node-positivity (OR = 0.59; 95% confidence interval [CI]: 0.57-0.60). TNBC has distinct features regarding age, gender, geographic, and racial distribution. Compared to non-TNBC, TNBC is larger and higher grade, but less likely to have lymph node metastases.

Black/White Disparities in Receipt of Treatment and Survival Among Men With Early-Stage Breast Cancer.

PURPOSE: To examine the extent of black/white disparities in receipt of treatment and survival for early-stage breast cancer in men age 18 to 64 and ≥ 65 years. PATIENTS AND METHODS: We identified 725 non-Hispanic black (black) and 5,247 non-Hispanic white (white) men diagnosed with early-stage breast cancer from 2004 to 2011 in the National Cancer Data Base. We used multivariable logistic regression and calculated standardized risk ratios to predict receipt of treatment and a proportional hazards model to estimate overall hazard ratios (HRs) in black versus white men age 18 to 64 and ≥ 65 years, separately. RESULTS: Receipt of treatment was remarkably similar between blacks and whites in both age groups. Black and white older men had lower receipt of chemotherapy (39.2% and 42.0%, respectively) compared with younger patients (76.7% and 79.3%, respectively). Younger black men had a 76% higher risk of death than younger white men after adjustment for clinical factors only (HR, 1.76; 95% CI, 1.11 to 2.78), but this difference significantly diminished after subsequent adjustment for insurance and income (HR, 1.37; 95% CI, 0.83 to 2.24). In those age ≥ 65 years, the excess risk of death in blacks versus whites was nonsignificant and not affected by adjustment for covariates. CONCLUSION: The excess risk of death in black versus white men diagnosed with early-stage breast cancer was largely confined to those age 18 to 64 years and became nonsignificant after adjustment for differences in insurance and income. These findings suggest the importance of improving access to care in reducing racial disparities in male breast cancer mortality.

CHEK2 c.1100delC allele is rarely identified in Greek breast cancer cases.

The CHEK2 gene encodes a protein kinase that plays a crucial role in maintenance of genomic integrity and the DNA repair mechanism. CHEK2 germline mutations are associated with increased risk of breast cancer and other malignancies. From a clinical perspective, the most significant mutation identified is the c.1100delC mutation, which is associated with an approximately 25% lifetime breast cancer risk. The distribution of this mutation shows wide geographical variation; it is more prevalent in the Northern European countries and less common, or even absent, in Southern Europe. In order to estimate the frequency of the CHEK2 c.1100delC mutation in Greek breast cancer patients, we genotyped 2,449 patients (2,408 females and 41 males), which was the largest series ever tested for c.1100delC. The mean age of female and male breast cancer diagnosis was 49 and 59 years, respectively. All patients had previously tested negative for the Greek BRCA1 founder and recurrent mutations. The CHEK2 c.1100delC mutation was detected in 0.16% (4 of 2,408) of females, all of whom were diagnosed with breast cancer before the age of 50 years. Only one c.1100delC carrier was reported with breast cancer family history. The present study indicates that the CHEK2 c.1100delC mutation does not contribute substantially to hereditary breast cancer in patients of Greek descent.

Male breast carcinoma: a clinicopathological and immunohistochemical characterization study.

Male breast carcinoma is a relatively rare disease. This study retrospectively investigated the clinicopathological features of 73 cases of male breast carcinoma in Chinese population, and classified the molecular subtype based on surrogate immunohistochemical definitions. The expression of GCDFP15, MGB, AR and FOXP1 were evaluated. Invasive carcinoma of no special type was the most common histological type in the study group (71.2%, 52/73). The luminal A and B subtypes were the major types of male breast carcinoma (60.9%, 34.8% respectively). AR and FOXP1 are expressed in 84.2% (48/57) and 71.9% (41/57) of the studied cases. Carcinoma of the luminal A subtype expressed GCDFP15 (73.5%, 25/34) and MGB (58.8%, 20/34) more frequently than cases of the luminal B subtypes (34.8%, 8/23 and 43.5%, 10/23, respectively; P = 0.004, P = 0.255, respectively). In conclusion, invasive carcinoma of no special type was the most common histological type in male breast carcinoma among Chinese population. Our study revealed that the luminal A and B subtypes were the major types of male breast carcinoma. AR and FOXP1 are highly expressed in male breast cancer. The luminal A subtype tends to express GCDFP15 and MGB more frequently than the luminal B subtype.

Male breast cancer according to tumor subtype and race: a population-based study.

BACKGROUND: Breast cancer occurs rarely in men. To the authors' knowledge, no population-based estimates of the incidence of human epidermal growth factor receptor 2 (HER2)-positive breast cancer or of the distribution of breast cancer subtypes among male breast cancer patients have been published to date. Therefore, the objective of the current study was to explore breast tumor subtype distribution by race/ethnicity among men in the large, ethnically diverse population of California. METHODS: This study included men who were diagnosed with invasive breast cancer between 2005 and 2009 with known estrogen receptor (ER) and progesterone receptor (PR) (together, hormone receptor [HR]) status and HER2 status reported to the California Cancer Registry. Among the men with HR-positive tumors, survival probabilities between groups were compared using log-rank tests. RESULTS: Six hundred six patients were included. The median age at diagnosis was 68 years. Four hundred ninety-four men (81.5%) had HR-positive tumors (defined as ER-positive and/or PR-positive and HER2-negative). Ninety men (14.9%) had HER2-positive tumors, and 22 (3.6%) had triple receptor-negative (TN) tumors. Among the patients with HR-positive tumors, non-Hispanic black men and Hispanic men were more likely to have PR-negative tumors than non-Hispanic white men. No statistically significant differences in survival were observed according to tumor subtype (P = .08). Differences in survival according to race/ethnicity were observed among all patients (P = .087) and among those with HR-positive tumors (P = .0170), and non-Hispanic black men had poorer outcomes. CONCLUSIONS: In this large, representative cohort of men with breast cancer, the distribution of tumor subtypes was different from that reported for women and varied by patient race/ethnicity. Non-Hispanic black men were more likely to have TN tumors and ER-positive/PR-negative tumors than white men.

Prevalence and type of BRCA mutations in Hispanics undergoing genetic cancer risk assessment in the southwestern United States: a report from the Clinical Cancer Genetics Community Research Network.

PURPOSE: To determine the prevalence and type of BRCA1 and BRCA2 (BRCA) mutations among Hispanics in the Southwestern United States and their potential impact on genetic cancer risk assessment (GCRA). PATIENTS AND METHODS: Hispanics (n = 746) with a personal or family history of breast and/or ovarian cancer were enrolled in an institutional review board-approved registry and received GCRA and BRCA testing within a consortium of 14 clinics. Population-based Hispanic breast cancer cases (n = 492) enrolled in the Northern California Breast Cancer Family Registry, negative by sequencing for BRCA mutations, were analyzed for the presence of the BRCA1 ex9-12del large rearrangement. RESULTS: Deleterious BRCA mutations were detected in 189 (25%) of 746 familial clinic patients (124 BRCA1, 65 BRCA2); 21 (11%) of 189 were large rearrangement mutations, of which 62% (13 of 21) were BRCA1 ex9-12del. Nine recurrent mutations accounted for 53% of the total. Among these, BRCA1 ex9-12del seems to be a Mexican founder mutation and represents 10% to 12% of all BRCA1 mutations in clinic- and population-based cohorts in the United States. CONCLUSION: BRCA mutations were prevalent in the largest study of Hispanic breast and/or ovarian cancer families in the United States to date, and a significant proportion were large rearrangement mutations. The high frequency of large rearrangement mutations warrants screening in every case. We document the first Mexican founder mutation (BRCA1 ex9-12del), which, along with other recurrent mutations, suggests the potential for a cost-effective panel approach to ancestry-informed GCRA.

Accuracy of BRCA1/2 mutation prediction models for different ethnicities and genders: experience in a southern Chinese cohort.

BACKGROUND: BRCA1/2 mutation prediction models (BRCAPRO, Myriad II, Couch, Shattuck-Eidens, BOADICEA) are well established in western cohorts to estimate the probability of BRCA1/2 mutations. Results are conflicting in Asian populations. Most studies did not account for gender-specific prediction. We evaluated the performance of these models in a Chinese cohort, including males, before BRCA1/2 mutation testing. METHODS: The five risk models were used to calculate the probability of BRCA mutations in probands with breast and ovarian cancers; 267 were non-BRCA mutation carriers (247 females and 20 males) and 43 were BRCA mutation carriers (38 females and 5 males). RESULTS: Mean BRCA prediction scores for all models were statistically better for carriers than noncarriers for females but not for males. BRCAPRO overestimated the numbers of female BRCA1/2 mutation carriers at thresholds ≥20% but underestimated if <20%. BRCAPRO and BOADICEA underestimated the number of male BRCA1/2 mutation carriers whilst Myriad II underestimated the number of both male and female carriers. In females, BRCAPRO showed similar discrimination, as measured by the area under the receiver operator characteristic curve (AUC) for BRCA1/2 combined mutation prediction to BOADICEA, but performed better than BOADICEA in BRCA1 mutation prediction (AUC 93% vs. 87%). BOADICEA had the best discrimination for BRCA1/2 combined mutation prediction (AUC 87%) in males. CONCLUSIONS: The variation in model performance underscores the need for research on larger Asian cohorts as prediction models, and the possible need for customizing these models for different ethnic groups and genders.

Genomic large rearrangement screening of BRCA1 and BRCA2 genes in high-risk Turkish breast/ovarian cancer patients by using multiplex ligation-dependent probe amplification assay.

In this study, MLPA assay was performed for detection of large rearrangements of BRCA1 and BRCA2 genes in 16 familial, 29 early onset, 3 male breast cancer, and 2 bilateral breast/ovarian cancer high risk Turkish index cases. MLPA assay for all exons of both genes and for 1100delC variant of CHEK2 gene were performed. Analyses, revealed no large genomic rearrangements in both genes, and, no 1100del variant in CHEK2 gene. Our data which represents the first results for Turkish patients, suggest that, the frequency of BRCA1 and BRCA2 genes' large rearrangements is very low.

Mutational profile of the CAV-1 gene in breast cancer cases in the ethnic Kashmiri population.

The role of caveolae and the caveolin proteins in cancer has been the subject of extensive research. It has been suggested that Caveolin-1 may contribute to certain steps of carcinogenesis in various types of cancer. Therefore in our study we focused on the potential clinical relevance of Caveolin-1 in 130 malignant breast tissue specimens along with their adjacent normal tissues. Using allele specific PCR we were able to rule out the mutation status of all the samples and then we did the conventional PCR-SSCP and sequencing of the mutated samples along with the normal adjacent tissues. Caveolin-1 was identified in a screen for genes involved in breast cancer progression and we demonstrated 29.2% mutational status in our Kashmiri ethnic population. We were able to detect 38 mutations out of which 22 were missense, 4 were nonsense, and 12 were frame shifts. Ten novel Cav-1 mutations (missense and frameshift). We conclude that the gene encoding CAV-1 plays an important role in the promotion of mammary tumorigenesis in Kashmir.

Large BRCA1 and BRCA2 genomic rearrangements in Malaysian high risk breast-ovarian cancer families.

Early studies of genetic predisposition due to the BRCA1 and BRCA2 genes have focused largely on sequence alterations, but it has now emerged that 4-28% of inherited mutations in the BRCA genes may be due to large genomic rearrangements of these genes. However, to date, there have been relatively few studies of large genomic rearrangements in Asian populations. We have conducted a full sequencing and large genomic rearrangement analysis (using Multiplex Ligation-dependent Probe Amplification, MLPA) of 324 breast cancer patients who were selected from a multi-ethnic hospital-based cohort on the basis of age of onset of breast cancer and/or family history. Three unrelated individuals were found to have large genomic rearrangements: 2 in BRCA1 and 1 in BRCA2, which accounts for 2/24 (8%) of the total mutations detected in BRCA1 and 1/23 (4%) of the mutations in BRCA2 detected in this cohort. Notably, the family history of the individuals with these mutations is largely unremarkable suggesting that family history alone is a poor predictor of mutation status in Asian families. In conclusion, this study in a multi-ethnic (Malay, Chinese, Indian) cohort suggests that large genomic rearrangements are present at a low frequency but should nonetheless be included in the routine testing for BRCA1 and BRCA2.

Searching for large genomic rearrangements of the BRCA1 gene in a Nigerian population.

BRCA1/2 germline mutations predispose to breast and ovarian cancer. Large genomic rearrangements (LGRs) have widened the mutational spectrum of the BRCA1 gene, but the frequencies vary in different populations. In this study, we want to determine the spectrum of LGRs in BRCA1 gene in Nigerian breast cancer patients. The multiplex ligation-dependent probe amplification (MLPA) assay was used to screen BRCA1 rearrangements in 352 patients who previously tested negative for BRCA1 and BRCA2 point mutations and small insertions/deletions. Positive MLPA result was confirmed and located by long-range PCR. The breakpoints of the candidate rearrangement were characterized by sequencing. A novel deletion of BRCA1 exon 21 (c.5277 + 480_5332 + 672del) was detected in 1 out of 352 Nigerian breast cancer patients (0.3% occurrence frequency). Further analysis of breakpoints revealed that the deletion involves two Alu-elements: one AluSg in intron 20 and the AluY in intron 21. These data suggest that while BRCA1 genomic rearrangement exists, they do not contribute significantly to BRCA1-associated risk in the Nigerian population.

Absence of genomic BRCA1 and BRCA2 rearrangements in Ashkenazi breast and ovarian cancer families.

A substantial proportion of Ashkenazi Jewish (AJ) breast and ovarian cancer families carry one of three founder mutations in BRCA1 (185delAG, 5382InsC) and BRCA2 (6174delT). Non-founder mutations are identified in another 2-4% of such families. The extent to which major genomic rearrangements in BRCA contribute to breast and ovarian cancer in the Ashkenazim is not well understood. We identified AJ individuals with breast and/or ovarian cancer undergoing hereditary breast/ovarian cancer risk assessment since 2006 without evidence of a deleterious mutation on BRCA gene sequencing who were screened for major gene rearrangements in BRCA1 and BRCA2. For each proband, the pre-test probability of identifying a deleterious BRCA mutation was estimated using the Myriad II model. We identified 108 affected individuals who underwent large rearrangement testing (80 breast cancer, 19 ovarian cancer, nine both breast and ovarian cancer). The mean estimated AJ specific pre-test probability of a deleterious mutation in BRCA1 and BRCA2 was 24.7% (range: 4.4-88.9%). No genomic rearrangements were identified in either the entire group or in the 26 subjects with pre-test mutation prevalence estimates exceeding 30%. Major gene rearrangements involving the BRCA1 and BRCA2 genes appear to contribute little to the burden of inherited predisposition to breast and ovarian cancer in the Ashkenazim.

Plasma sex hormone concentrations and breast cancer risk in an ethnically diverse population of postmenopausal women: the Multiethnic Cohort Study.

To add to the existing evidence that comes mostly from White populations, we conducted a nested case-control study to examine the association between sex hormones and breast cancer risk within the Multiethnic Cohort that includes Japanese American, White, Native Hawaiian, African American, and Latina women. Of the postmenopausal women for whom we had a plasma sample, 132 developed breast cancer during follow-up. Two controls per case, matched on study area (Hawaii, Los Angeles), ethnicity/race, birth year, date and time of blood draw and time fasting, were randomly selected from the women who had not developed breast cancer. Levels of estradiol (E(2)), estrone (E(1)), androstenedione, dehydroepiandrosterone (DHEA), and testosterone were quantified by RIA after organic extraction and Celite column partition chromatography. E(1) sulfate, DHEA sulfate (DHEAS), and sex hormone-binding globulin (SHBG) were quantified by direct immunoassays. Based on conditional logistic regression, the sex hormones were positively associated and SHBG was negatively associated with breast cancer risk. All associations, except those with DHEAS and testosterone showed a significant linear trend. The odds ratio (OR) associated with a doubling of E(2) levels was 2.26 (95% confidence interval (CI) 1.58-3.25), and the OR associated with a doubling of testosterone levels was 1.34 (95% CI 0.98-1.82). The associations in Japanese American women, who constituted 54% of our sample, were similar to or nonsignificantly stronger than in the overall group. This study provides the best evidence to date that the association between sex hormones and breast cancer risk is generalizable to an ethnically diverse population.