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- Begg, Colin B, et al.
(författare)
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Variation of breast cancer risk among BRCA1/2 carriers
- 2008
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Ingår i: JAMA: The Journal of the American Medical Association. - : American Medical Association (AMA). - 1538-3598. ; 299:2, s. 194-201
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: The risk of breast cancer in BRCA1 and BRCA2 mutation carriers has been examined in many studies, but relatively little attention has been paid to the degree to which the risk may vary among carriers. OBJECTIVES: To determine the extent to which risks for BRCA1 and BRCA2 carriers vary with respect to observable and unobservable characteristics. DESIGN, SETTING, AND PARTICIPANTS: Probands were identified from a population-based, case-control study (Women's Environmental Cancer and Radiation Epidemiology [WECARE]) of asynchronous contralateral breast cancer conducted during the period of January 2000 to July 2004. Participants previously diagnosed with contralateral breast cancer or unilateral breast cancer were genotyped for mutations in BRCA1 and BRCA2. All participants had their initial breast cancer diagnosed during the period of January 1985 to December 2000, before the age of 55 years. MAIN OUTCOME MEASURE: Incidence of breast cancer in first-degree female relatives of the probands was examined and compared on the basis of proband characteristics and on the basis of variation between families. RESULTS: Among the 1394 participants with unilateral breast cancer, 73 (5.2%) were identified as carriers of deleterious mutations (42 with BRCA1 and 31 with BRCA2). Among the 704 participants with contralateral breast cancer, 108 (15.3%) were identified as carriers of deleterious mutations (67 with BRCA1 and 41 with BRCA2). Among relatives of carriers, risk was significantly associated with younger age at diagnosis in the proband (P = .04), and there was a trend toward higher risk for relatives of contralateral breast cancer vs unilateral breast cancer participants (odds ratio, 1.4 [95% confidence interval, 0.8-2.4]; P = .28). In addition, there were significant differences in risk between carrier families after adjusting for these observed characteristics. CONCLUSION: There exists broad variation in breast cancer risk among carriers of BRCA1 and BRCA2 mutations.
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| 2. |
- Figueiredo, Jane C., et al.
(författare)
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Oral contraceptives and postmenopausal hormones and risk of contralateral breast cancer among BRCA1 and BRCA2 mutation carriers and noncarriers: the WECARE Study
- 2010
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 120:1, s. 175-183
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Tidskriftsartikel (refereegranskat)abstract
- The potential effects of oral contraceptive (OC) and postmenopausal hormone (PMH) use are not well understood among BRCA1 or BRCA2 (BRCA1/2) deleterious mutation carriers with a history of breast cancer. We investigated the association between OC and PMH use and risk of contralateral breast cancer (CBC) in the WECARE (Women's Environment, Cancer, and Radiation Epidemiology) Study. The WECARE Study is a population-based case-control study of 705 women with asynchronous CBC and 1,398 women with unilateral breast cancer, including 181 BRCA1/2 mutation carriers. Risk-factor information was assessed by telephone interview. Mutation status was measured using denaturing high-performance liquid chromatography followed by direct sequencing in all participants. Outcomes, treatment, and tumor characteristics were abstracted from medical records. Ever use of OCs was not associated with risk among noncarriers (RR = 0.87; 95% CI = 0.66-1.15) or BRCA2 carriers (RR = 0.82; 95% CI = 0.21-3.13). BRCA1 carriers who used OCs had a nonsignificant greater risk than nonusers (RR = 2.38; 95% CI = 0.72-7.83). Total duration of OC use and at least 5 years of use before age 30 were associated with a nonsignificant increased risk among mutation carriers but not among noncarriers. Few women had ever used PMH and we found no significant associations between lifetime use and CBC risk among carriers and noncarriers. In conclusion, the association between OC/PMH use and risk of CBC does not differ significantly between carriers and noncarriers; however, because carriers have a higher baseline risk of second primaries, even a potential small increase in risk as a result of OC use may be clinically relevant.
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| 3. |
- Poynter, Jenny N., et al.
(författare)
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Reproductive factors and risk of contralateral breast cancer by BRCA1 and BRCA2 mutation status: results from the WECARE study
- 2010
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Ingår i: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 1573-7225 .- 0957-5243. ; 21:6, s. 839-846
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Tidskriftsartikel (refereegranskat)abstract
- Reproductive factors, such as early age at menarche, late age at menopause, and nulliparity are known risk factors for breast cancer. Previously, we reported these factors to be associated with risk of developing contralateral breast cancer (CBC). In this study, we evaluated the association between these factors and CBC risk among BRCA1 and BRCA2 (BRCA1/2) mutation carriers and non-carriers. The WECARE Study is a population-based multi-center case-control study of 705 women with CBC (cases) and 1,397 women with unilateral breast cancer (controls). All participants were screened for BRCA1/2 mutations and 181 carriers were identified. Conditional logistic regression models were used to evaluate associations between reproductive factors and CBC for mutation carriers and non-carriers. None of the associations between reproductive factors and CBC risk differed between mutation carriers and non-carriers. The increase in risk with younger age at menarche and decrease in risk in women with more than two full-term pregnancies seen in non-carriers were not significantly different in carriers (adjusted RRs = 1.31, 95% CI 0.65-2.65 and 0.53, 95% CI 0.19-1.51, respectively). No significant associations between the other reproductive factors and CBC risk were observed in mutation carriers or non-carriers. For two reproductive factors previously shown to be associated with CBC risk, we observed similar associations for BRCA1/2 carriers. This suggests that reproductive variables that affect CBC risk may have similar effects in mutation carriers and non-carriers.
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| 4. |
- Reding, Kerryn W., et al.
(författare)
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Genetic variants on chromosome 5p12 are associated with risk of breast cancer in African American women: the Black Women's Health Study
- 2010
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 123:2, s. 491-498
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Tidskriftsartikel (refereegranskat)abstract
- Two single nucleotide polymorphisms (SNPs), rs4415084, and rs10941679 on chromosome 5p12 were associated with risk of breast cancer in a recent genome-wide association study (GWAS) of women of European ancestry. Both SNPs are located in a large high-LD region and the causal variant(s) are still unknown. We conducted a nested case-control study in a cohort of African American women to replicate and narrow the region carrying the causal variant(s). We evaluated 14 tagging SNPs in a 98 kb LD block surrounding the index SNPs in 886 breast cancer cases and 1,089 controls from the Black Women's Health Study. We used the Cochran-Armitage trend test to assess association with breast cancer risk. Odds ratios were derived from logistic regression analyses adjusted for potential confounders including percent European admixture. We confirmed the reported association of rs4415084 SNP with overall risk of breast cancer (P = 0.06), and, as in the original study, observed a stronger association with estrogen receptor positive tumors (P = 0.03). We identified four other SNPs (rs6451770, rs12515012, rs13156930, and rs16901937) associated with risk of breast cancer at the nominal alpha value of 0.05; all of them were located in a 59 kb HapMap YRI LD block. After correction for multiple testing, the association with SNP rs16901937 remained significant (P permutated = 0.038). The G allele was associated with a 21% increased risk of breast cancer overall and with a 32% increase in tumors positive for both estrogen and progesterone receptors. The present results from an African ancestry (AA) population confirm the presence of breast cancer susceptibility genetic variants in the chromosome 5p12 region. We successfully used the shorter range of LD in our AA sample to refine the localization of the putative causal variant.
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