| 1. |
- Narod, SA, et al.
(författare)
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Oral contraceptives and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers
- 2002
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 1460-2105. ; 94:23, s. 1773-1779
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Tidskriftsartikel (refereegranskat)abstract
- Background: Oral contraceptive use has been associated with an increase in the risk of breast cancer in young women. We examined whether this association is seen in women at high risk of breast cancer because they carry a mutation in one of two breast cancer susceptibility genes, BRCA1 and BRCA2. Methods: We performed a matched case-control study on 1311 pairs of women with known deleterious BRCA1 and/or BRCA2 mutations recruited from 52 centers in 11 countries. Women who had been diagnosed with breast cancer were matched to control subjects by year of birth, country of residence, mutation (BRCA1 or BRCA2), and history of ovarian cancer. All study subjects completed a questionnaire about oral contraceptive use. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived by conditional logistic regression. All statistical tests were two-sided. Results: Among BRCA2 mutation carriers, ever use of oral contraceptives was not associated with an increased risk of breast cancer (OR = 0.94, 95% CI = 0.72 to 1.24). For BRCAI mutation carriers, ever use of oral contraceptives was associated With a modestly increased risk of breast cancer (OR = 1.20, 95 % CI = 1.02 to 1.40). However, compared with BRCA1 mutation carriers who never used oral contraceptives, those who used oral contraceptives for at least 5 years had an increased risk of breast cancer (OR = 1.33, 95% CI = 1.11 to 1.60), as did those who used oral contraceptives before age 30 (OR = 1.29, 95% CI = 1.09 to 1.52), those who were diagnosed with breast cancer before age 40 (OR = 1.38, 95% CI = 1.11 to 1.72), and those who first used oral contraceptives before 1975 (OR = 1.42, 95 % CI = 1.17 to 1.75). Conclusions: Among BRCA1 mutation carriers, women who first used oral contraceptives before 1975, who used them before age 30, or who used them for 5 or more years may have an increased risk of early-onset breast cancer. Oral contraceptives do not appear to be associated with risk of breast cancer in BRCA2 carriers, but data for BRCA2 carriers are limited.
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| 2. |
- Moller, P., et al.
(författare)
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Genetic epidemiology of BRCA1 mutations in Norway
- 2001
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Ingår i: European Journal of Cancer. - 1879-0852. ; 37:18, s. 2428-2434
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Tidskriftsartikel (refereegranskat)abstract
- Familial breast-ovarian cancer has been demonstrated to be frequent but unevenly distributed in Norway. This was assumed to be caused by the reduced population size created by the medieval Bubonic plague, 25 generations ago, and by the following rapid expansion. We have previously reported that four mutations account for 68% of the BRCA1 mutation carriers. Subsequent analysis has resulted in a total of 100 separate families carrying one of these founder mutations. The four mutations occurred on one specific BRCA1 haplotype each. The 1675delA, 816delGT and 3347detAG families originated from the South-West coast of Norway with a few Families in the north, while the traceable ancestors of the 1135insA families clustered along the historical inland road from the South-East to mid-Norway. The carriers of each of the four mutations today are descendants of one or a few individuals surviving the plagues. We may identify the majority of BRCA1 mutation carriers in Norway by screening for local founder mutations.
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| 3. |
- Moller, P, et al.
(författare)
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Survival in prospectively ascertained familial breast cancer: Analysis of a series stratified by tumour characteristics, BRCA mutations and oophorectomy
- 2002
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136. ; 101:6, s. 555-559
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Tidskriftsartikel (refereegranskat)abstract
- Dedicated clinics have been established for the early diagnosis and treatment of women at risk for inherited breast cancer, but the effects of such interventions are currently unproven. This second report on prospectively diagnosed inherited breast cancer from the European collaborating centres supports the previous conclusions and adds information on genetic heterogeneity and the effect of oophorectomy. Of 249 patients, 20% had carcinoma in situ (CIS), 54% had infiltrating cancer without spread (CaNO) and 26% had cancer with spread (CaN+). Five-year survival was 100% for CIS, 94% for CaNO and 72% for CaN+ (p = 0.007). Thirty-six patients had BRCA1 mutations, and 8 had BRCA2 mutations. Presence of BRCA1 mutation was associated with infiltrating cancer, high grade and lack of oestrogen receptor (p < 0.05 for all 3 characteristics). For BRCA1 mutation carriers, 5-year survival was 63% vs. 91% for noncarriers (p = 0.04). For CaNO patients, mutation carriers had 75% S-year disease-free survival vs. 96% for noncarriers (p = 0.01). Twenty-one of the mutation carriers had undergone prophylactic oophorectomy, prior to or within 6 months of diagnosis in 13 cases. All but I relapse occurred in the I S who had kept their ovaries, (p < 0.01); no relapse occurred in those who had removed the ovaries within 6 months (p = 0.04) Contralateral cancer was more frequently observed in mutation noncarriers, but this finding did not reach statistical significance. Our findings support the concept that BRCA1 cancer is biologically different from other inherited breast cancers. While current screening protocols appear satisfactory for the majority of women at risk of familial breast cancer, this may not be the case for BRCA1 mutation carriers. The observed effect of oophorectomy was striking.
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| 4. |
- Möller, P, et al.
(författare)
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The BRCA1 syndrome and other inherited breast or breast-ovarian cancers in a Norwegian prospective series
- 2001
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Ingår i: European Journal of Cancer. - 1879-0852. ; 37:8, s. 1027-1032
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Tidskriftsartikel (refereegranskat)abstract
- Inherited breast cancer is a heterogenous group of diseases. We examined this heterogeneity in a prospective series of inherited breast and ovarian cancers, previously demonstrated to include 84% of inherited cancers. Ninety-two tumours (65 breast and 27 ovarian) in 82 patients from 70 kindreds were prospectively diagnosed. Fifteen of the breast cancers were in situ, 50 were infiltrating. 40 (49%) of the 82 women carried a BRCA1 mutation, whereas no mutation in BRCA2 was found. Approximately, two-thirds of the BRCA1 mutation carriers had one of the four most frequent Norwegian founder mutations. Ninety-five per cent of the epithelial ovarian cancers occurred in BRCA1 mutation carrying women versus 38% of infiltrating breast cancers and 7% of carcinoma in situ of the breast. The BRCA1 syndrome was phenotypically distinct with invasive, high grade, oestrogen receptor-negative breast cancers and epithelial ovarian cancers. Non-BRCA1/2 inherited breast cancers included carcinoma in situ and lobular carcinoma and were frequently bilateral. Non-BRCA1/2 inherited breast cancer is not associated with epithelial ovarian cancer and in breast cancers has distinct biological characteristics, indicating that the different subgroups of inherited breast cancer may need different healthcare services.
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