Common breast cancer-predisposition alleles are associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers.

Germline mutations in BRCA1 and BRCA2 confer high risks of breast cancer. However, evidence suggests that these risks are modified by other genetic or environmental factors that cluster in families. A recent genome-wide association study has shown that common alleles at single nucleotide polymorphisms (SNPs) in FGFR2 (rs2981582), TNRC9 (rs3803662), and MAP3K1 (rs889312) are associated with increased breast cancer risks in the general population. To investigate whether these loci are also associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers, we genotyped these SNPs in a sample of 10,358 mutation carriers from 23 studies. The minor alleles of SNP rs2981582 and rs889312 were each associated with increased breast cancer risk in BRCA2 mutation carriers (per-allele hazard ratio [HR] = 1.32, 95% CI: 1.20-1.45, p(trend) = 1.7 x 10(-8) and HR = 1.12, 95% CI: 1.02-1.24, p(trend) = 0.02) but not in BRCA1 carriers. rs3803662 was associated with increased breast cancer risk in both BRCA1 and BRCA2 mutation carriers (per-allele HR = 1.13, 95% CI: 1.06-1.20, p(trend) = 5 x 10(-5) in BRCA1 and BRCA2 combined). These loci appear to interact multiplicatively on breast cancer risk in BRCA2 mutation carriers. The differences in the effects of the FGFR2 and MAP3K1 SNPs between BRCA1 and BRCA2 carriers point to differences in the biology of BRCA1 and BRCA2 breast cancer tumors and confirm the distinct nature of breast cancer in BRCA1 mutation carriers.

No association of TGFB1 L10P genotypes and breast cancer risk in BRCA1 and BRCA2 mutation carriers: a multi-center cohort study.

BACKGROUND: The transforming growth factor beta-1 gene (TGFB1) is a plausible candidate for breast cancer susceptibility. The L10P variant of TGFB1 is associated with higher circulating levels and secretion of TGF-beta, and recent large-scale studies suggest strongly that this variant is associated with breast cancer risk in the general population. METHODS: To evaluate whether TGFB1 L10P also modifies the risk of breast cancer in BRCA1 or BRCA2 mutation carriers, we undertook a multi-center study of 3,442 BRCA1 and 2,095 BRCA2 mutation carriers. RESULTS: We found no evidence of association between TGFB1 L10P and breast cancer risk in either BRCA1 or BRCA2 mutation carriers. The per-allele HR for the L10P variant was 1.01 (95%CI: 0.92-1.11) in BRCA1 carriers and 0.92 (95%CI: 0.81-1.04) in BRCA2 mutation carriers. CONCLUSIONS: These results do not support the hypothesis that TGFB1 L10P genotypes modify the risk of breast cancer in BRCA1 or BRCA2 mutation carriers.

The BRCA1 Ashkenazi founder mutations occur on common haplotypes and are not highly correlated with anonymous single nucleotide polymorphisms likely to be used in genome-wide case-control association studies.

BACKGROUND: We studied linkage disequilibrium (LD) patterns at the BRCA1 locus, a susceptibility gene for breast and ovarian cancer, using a dense set of 114 single nucleotide polymorphisms in 5 population groups. We focused on Ashkenazi Jews in whom there are known founder mutations, to address the question of whether we would have been able to identify the 185delAG mutation in a case-control association study (should one have been done) using anonymous genetic markers. This mutation is present in approximately 1% of the general Ashkenazi population and 4% of Ashkenazi breast cancer cases. We evaluated LD using pairwise and haplotype-based methods, and assessed correlation of SNPs with the founder mutations using Pearson's correlation coefficient. RESULTS: BRCA1 is characterized by very high linkage disequilibrium in all populations spanning several hundred kilobases. Overall, haplotype blocks and pair-wise LD bins were highly correlated, with lower LD in African versus non-African populations. The 185delAG and 5382insC founder mutations occur on the two most common haplotypes among Ashkenazim. Because these mutations are rare, even though they are in strong LD with many other SNPs in the region as measured by D-prime, there were no strong associations when assessed by Pearson's correlation coefficient, r (maximum of 0.04 for the 185delAG). CONCLUSION: Since the required sample size is related to the inverse of r, this suggests that it would have been difficult to map BRCA1 in an Ashkenazi case-unrelated control association study using anonymous markers that were linked to the founder mutations.

Risk Stratification System for Oral Cancer Screening.

Oral cavity and oropharyngeal cancer (oral cancer) is a deadly disease that is increasing in incidence. Worldwide 5-year survival is only 50% due to delayed intervention with more than half of the diagnoses at stage III and IV, whereas earlier detection (stage I and II) yields survival rates up to 80% to 90%. Salivary soluble CD44 (CD44), a tumor-initiating marker, and total protein levels may facilitate oral cancer risk assessment and early intervention. This study used a hospital-based design with 150 cases and 150 frequency-matched controls to determine whether CD44 and total protein levels in oral rinses were associated with oral cancer independent of age, gender, race, ethnicity, tobacco and alcohol use, and socioeconomic status (SES). High-risk subjects receiving oral cancer prevention interventions as part of a community-based program (n = 150) were followed over 1 year to determine marker specificity and variation. CD44 ≥5.33 ng/mL was highly associated with case status [adjusted OR 14.489; 95% confidence interval (CI), 5.973-35.145; P < .0001, vs. reference group CD44 <2.22 ng/mL and protein <1.23 mg/mL]. Total protein aided prediction above CD44 alone. Sensitivity and specificity in the frequency-matched study was 80% and 48.7%, respectively. However, controls were not representative of the target screening population due, in part, to a high rate of prior cancer. In contrast, specificity in the high-risk community was 74% and reached 95% after annual retesting. Simple and inexpensive salivary CD44 and total protein measurements may help identify individuals at heightened risk for oral cancer from the millions who partake in risky behaviors. Cancer Prev Res; 9(6); 445-55. ©2016 AACR.

Salivary protein and solCD44 levels as a potential screening tool for early detection of head and neck squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is a devastating disease usually diagnosed at a late stage when cure rates are 40%. We examined a simple and inexpensive molecular tool that may aid HNSCC detection. METHODS: Building on prior findings that total protein levels are elevated in 102 HNSCC cases versus 84 control subjects, we further analyzed these levels with respect to important risk and demographic variables and compared the results to soluble CD44 (solCD44). Using multivariate adaptive regression splines (MARSs)-logit modeling and logistic regression, we determined whether total protein, solCD44, or the combination best identifies HNSCC. RESULTS: Combined higher levels of solCD44 and protein were significantly associated with HNSCC (odds ratio [OR] = 24.90; 95% confidence interval [CI], 9.04-68.57; area under the curve [AUC] = 0.786). A model including protein plus solCD44 resulted in a better area (AUC 0.796) than either marker alone. CONCLUSION: Oral rinse levels of solCD44 and protein seem to hold promise for detection of HNSCC.

Salivary markers and risk factor data: a multivariate modeling approach for head and neck squamous cell carcinoma detection.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is a debilitating and deadly disease largely due to late stage diagnosis. Prior work indicates that soluble CD44 (solCD44) and total protein may be useful diagnostic markers for HNSCC. In this study we combine the markers solCD44, IL-8, HA, and total protein with demographic and risk factor data to derive a multivariate logistic model that improves HNSCC detection as compared to our previous data using biomarkers alone. METHODS: We performed the solCD44, IL-8, HA, and total protein assays on oral rinses from 40 HNSCC patients and 39 controls using ELISA assays. Controls had benign diseases of the upper aerodigestive tract and a history of tobacco or alcohol use. All subjects completed a questionnaire including demographic and risk factor data. RESULTS: Depending on cancer subsite, differences between cases and controls were found for all markers. A multivariate logistic model including solCD44, total protein and variables related to smoking, oral health and education offered a significant improvement over the univariate models with an AUC of 0.853. Sensitivity ranged from 75-82.5% and specificity from 69.2-82.1% depending on predictive probability cut points. CONCLUSION: A multivariate model, including simple and inexpensive molecular tests in combination with risk factors, results in a promising tool for distinguishing HNSCC patients from controls. IMPACT: In this case-control study, the resulting observations led to an unprecedented multivariate model that distinguished HNSCC cases from controls with better accuracy than the current gold standard which includes oral examination followed by tissue biopsy. Since the components are simple, noninvasive, and inexpensive to obtain, this model combining biomarkers, risk factor and demographic data serves as a promising prototype for future cancer detection tests.