[Show abstract][Hide abstract] ABSTRACT: Breast density and single-nucleotide polymorphisms (SNPs) have both been associated with breast cancer risk. To determine the extent to which these two breast cancer risk factors are associated, we investigate the association between a panel of validated SNPs related to breast cancer and quantitative measures of mammographic density in a cohort of Caucasian and African-American women.
In this IRB-approved, HIPAA-compliant study, we analyzed a screening population of 639 women (250 African American and 389 Caucasian) who were tested with a validated panel assay of 12 SNPs previously associated to breast cancer risk. Each woman underwent digital mammography as part of routine screening and all were interpreted as negative. Both absolute and percent estimates of area and volumetric density were quantified on a per-woman basis using validated software. Associations between the number of risk alleles in each SNP and the density measures were assessed through a race-stratified linear regression analysis, adjusted for age, BMI, and Gail lifetime risk.
The majority of SNPs were not found to be associated with any measure of breast density. SNP rs3817198 (in LSP1) was significantly associated with both absolute area (p = 0.004) and volumetric (p = 0.019) breast density in Caucasian women. In African-American women, SNPs rs3803662 (in TNRC9/TOX3) and rs4973768 (in NEK10) were significantly associated with absolute (p = 0.042) and percent (p = 0.028) volume density respectively.
The majority of SNPs investigated in our study were not found to be significantly associated with breast density, even when accounting for age, BMI, and Gail risk, suggesting that these two different risk factors contain potentially independent information regarding a woman's risk to develop breast cancer. Additionally, the few statistically significant associations between breast density and SNPs were different for Caucasian versus African American women. Larger prospective studies are warranted to validate our findings and determine potential implications for breast cancer risk assessment.
BMC Cancer 12/2015; 15(1):1159. DOI:10.1186/s12885-015-1159-3 · 3.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The American Society of Clinical Oncology (ASCO) has long affirmed that the recognition and management of individuals with an inherited susceptibility to cancer are core elements of oncology care. ASCO released its first statement on genetic testing in 1996 and updated that statement in 2003 and 2010 in response to developments in the field. In 2014, the Cancer Prevention and Ethics Committees of ASCO commissioned another update to reflect the impact of advances in this area on oncology practice. In particular, there was an interest in addressing the opportunities and challenges arising from the application of massively parallel sequencing-also known as next-generation sequencing-to cancer susceptibility testing. This technology introduces a new level of complexity into the practice of cancer risk assessment and management, requiring renewed effort on the part of ASCO to ensure that those providing care to patients with cancer receive the necessary education to use this new technology in the most effective, beneficial manner. The purpose of this statement is to explore the challenges of new and emerging technologies in cancer genetics and provide recommendations to ensure their optimal deployment in oncology practice. Specifically, the statement makes recommendations in the following areas: germline implications of somatic mutation profiling, multigene panel testing for cancer susceptibility, quality assurance in genetic testing, education of oncology professionals, and access to cancer genetic services.
Journal of Clinical Oncology 09/2015; DOI:10.1200/JCO.2015.63.0996 · 18.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Advances in sequencing technology have made multigene testing, or "panel testing," a practical option when looking for genetic variants that may be associated with a risk of breast cancer. In June 2013, the U.S. Supreme Court(1) invalidated specific claims made by Myriad Genetics with respect to the patenting of the genomic DNA sequence of BRCA1 and BRCA2. Other companies immediately began to offer panel tests for breast cancer genes that included BRCA1 and BRCA2. The subsequent flourishing of gene-panel testing services (Table 1, and Table S1 in the Supplementary Appendix, available with the full text of this article at . . .
New England Journal of Medicine 05/2015; 372(23). DOI:10.1056/NEJMsr1501341 · 55.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We present a fully-automated method for deriving quantitative measures of background parenchymal enhancement (BPE) from breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perform a preliminary evaluation of these measures to assess the effect of risk-reducing salpingo-oophorectomy (RRSO) in a cohort of BReast CAncer susceptibility gene 1/2 (BRCA1/2) mutation carriers.
Breast DCE-MRI data from 50 BRCA1/2 carriers were retrospectively analyzed under the Health Insurance Portability and Accountability Act (HIPAA) and institutional review board approval. Both the absolute (| |) and relative ( %) measures of BPE and fibroglandular tissue (FGT) were computed from the MRI scans acquired before and after RRSO. These pre- and post-RRSO measures were compared using paired Student's t-test. The area under the curve (AUC) of the receiver operating characteristic (ROC) were used to evaluate the performance of relative changes in the BPE and FGT measures in predicting breast cancer developed among these women after the RRSO surgery.
For the 44 women who did not develop breast cancer after RRSO, absolute volume of BPE and FGT has a significant decrease (p < 0.05) post-RRSO, while for the 6 women who developed breast cancer there are no significant changes in these measures. Higher values in all BPE and FGT measures are also observed post-RRSO for the women who developed breast cancer, compared to women who did not. Relative changes in BPE % are most predictive of women who develop breast cancer after RRSO (p < 0.05), while combining BPE % and |FGT| yields an AUC of 0.80, higher than BPE % (AUC = 0.78) or |FGT| (AUC = 0.66) alone (both p > 0.02).
Quantitative measures of BPE and FGT are different before and after RRSO, and their relative changes are associated with prediction of developing breast cancer, potentially indicative of women who are more susceptible to develop breast cancer after RRSO in BRCA1/2 mutation carriers.
Breast cancer research: BCR 05/2015; 17(1):67. DOI:10.1186/s13058-015-0577-0 · 5.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective:
Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3' UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370.
Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers).
We found no association with risk of ovarian cancer (OR=0.99, 95% CI 0.94-1.04, p=0.74) or breast cancer (OR=0.98, 95% CI 0.94-1.01, p=0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR=1.09, 95% CI 0.97-1.23, p=0.14, breast cancer HR=1.04, 95% CI 0.97-1.12, p=0.27; BRCA2, ovarian cancer HR=0.89, 95% CI 0.71-1.13, p=0.34, breast cancer HR=1.06, 95% CI 0.94-1.19, p=0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR=0.94, 95% CI 0.83-1.07, p=0.38), breast cancer (HR=0.96, 95% CI 0.87-1.06, p=0.38), and all other previously-reported associations.
rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers.
[Show abstract][Hide abstract] ABSTRACT: Individuals carrying pathogenic mutations in BRCA1/2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals from different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. Here we test the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers.
We genotyped 22214 (11421 affected, 10793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched for affected or unaffected individuals.
We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers than the rest of clade T, (Hazard Ratio (HR) = 0.55 (95% Confidence Interval (CI) 0.34-0.88, p-value = 0.01). Compared with the most frequent haplogroup in the general population i.e. H and T clade, the T1a1 haplogroup has an HR = 0.62 (95% CI = 0.40-0.95, p-value = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk.
This study illustrates how original approaches like the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.
Breast cancer research: BCR 04/2015; 17(1):61. DOI:10.1186/s13058-015-0567-2 · 5.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: IMPORTANCE: Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists.
OBJECTIVE:To identify mutation-specific cancer risks for carriers of BRCA1/2.
DESIGN, SETTING, AND PARTICIPANTS:Observational study of women who were ascertained between 1937 and 2011 (median, 1999) and found to carry disease-associated BRCA1 or BRCA2 mutations. The international sample comprised 19,581 carriers of BRCA1 mutations and 11,900 carriers of BRCA2 mutations from 55 centers in 33 countries on 6 continents. We estimated hazard ratios for breast and ovarian cancer based on mutation type, function, and nucleotide position. We also estimated RHR, the ratio of breast vs ovarian cancer hazard ratios. A value of RHR greater than 1 indicated elevated breast cancer risk; a value of RHR less than 1 indicated elevated ovarian cancer risk.
EXPOSURES:Mutations of BRCA1 or BRCA2.
MAIN OUTCOMES AND MEASURES: Breast and ovarian cancer risks.
RESULTS:Among BRCA1 mutation carriers, 9052 women (46%) were diagnosed with breast cancer, 2317 (12%) with ovarian cancer, 1041 (5%) with breast and ovarian cancer, and 7171 (37%) without cancer. Among BRCA2 mutation carriers, 6180 women (52%) were diagnosed with breast cancer, 682 (6%) with ovarian cancer, 272 (2%) with breast and ovarian cancer, and 4766 (40%) without cancer. In BRCA1, we identified 3 breast cancer cluster regions (BCCRs) located at c.179 to c.505 (BCCR1; RHR = 1.46; 95% CI, 1.22-1.74; P = 2 × 10(-6)), c.4328 to c.4945 (BCCR2; RHR = 1.34; 95% CI, 1.01-1.78; P = .04), and c. 5261 to c.5563 (BCCR2', RHR = 1.38; 95% CI, 1.22-1.55; P = 6 × 10(-9)). We also identified an ovarian cancer cluster region (OCCR) from c.1380 to c.4062 (approximately exon 11) with RHR = 0.62 (95% CI, 0.56-0.70; P = 9 × 10(-17)). In BRCA2, we observed multiple BCCRs spanning c.1 to c.596 (BCCR1; RHR = 1.71; 95% CI, 1.06-2.78; P = .03), c.772 to c.1806 (BCCR1'; RHR = 1.63; 95% CI, 1.10-2.40; P = .01), and c.7394 to c.8904 (BCCR2; RHR = 2.31; 95% CI, 1.69-3.16; P = .00002). We also identified 3 OCCRs: the first (OCCR1) spanned c.3249 to c.5681 that was adjacent to c.5946delT (6174delT; RHR = 0.51; 95% CI, 0.44-0.60; P = 6 × 10(-17)). The second OCCR spanned c.6645 to c.7471 (OCCR2; RHR = 0.57; 95% CI, 0.41-0.80; P = .001). Mutations conferring nonsense-mediated decay were associated with differential breast or ovarian cancer risks and an earlier age of breast cancer diagnosis for both BRCA1 and BRCA2 mutation carriers.
CONCLUSIONS AND RELEVANCE: Breast and ovarian cancer risks varied by type and location of BRCA1/2 mutations. With appropriate validation, these data may have implications for risk assessment and cancer prevention decision making for carriers of BRCA1 and BRCA2 mutations.
JAMA The Journal of the American Medical Association 04/2015; 313(13):1347-61. DOI:10.1001/jama.2014.5985 · 35.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The risks, benefits, and utilities of multiplex panels for breast cancer susceptibility are unknown, and new counseling and informed consent models are needed. We sought to obtain patient feedback and early outcome data with a novel tiered-binned model for multiplex testing.
BRCA1/2-negative and untested patients completed pre- and posttest counseling and surveys evaluating testing experiences and cognitive and affective responses to multiplex testing.
Of 73 patients, 49 (67%) completed pretest counseling. BRCA1/2-negative patients were more likely to proceed with multiplex testing (86%) than those untested for BRCA1/2 (43%; P < 0.01). Many patients declining testing reported concern for uncertainty and distress. Most patients would not change anything about their pre- (76%) or posttest (89%) counseling sessions. Thirty-three patients (72%) were classified as making an informed choice, including 81% of those who proceeded with multiplex testing. Knowledge increased significantly. Anxiety, depression, uncertainty, and cancer worry did not significantly increase with multiplex testing.
Some patients, particularly those without prior BRCA1/2 testing, decline multiplex testing. Most patients who proceeded with testing did not experience negative psychological responses, but larger studies are needed. The tiered-binned approach is an innovative genetic counseling and informed consent model for further study in the era of multiplex testing.Genet Med advance online publication 02 April 2015Genetics in Medicine (2015); doi:10.1038/gim.2015.19.
Genetics in medicine: official journal of the American College of Medical Genetics 04/2015; DOI:10.1038/gim.2015.19 · 7.33 Impact Factor