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- Kotsopoulos, Joanne, et al.
(författare)
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Infertility, treatment of infertility, and the risk of breast cancer among women with BRCA1 and BRCA2 mutations : a case-control study
- 2008
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Ingår i: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 1573-7225 .- 0957-5243. ; 19:10, s. 9-1111
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Women with a breast cancer susceptibility gene 1 (BRCA1) or breast cancer susceptibility gene 2 (BRCA2) mutation are at increased risk for developing breast and ovarian cancer. Various reproductive and hormonal factors have been shown to modify the risk of breast cancer. These studies suggest that estrogen exposure and deprivation are important in the etiology of hereditary cancer. Many patients are interested in the possibility of an adverse effect of fertility treatment on breast cancer risk. It is important to evaluate whether or not infertility per se or exposure to fertility medications increase the risk of breast cancer in genetically predisposed women.METHODS: We conducted a matched case-control study of 1,380 pairs of women with a BRCA1 or BRCA2 mutation to determine if a history of infertility, the use of fertility medications, or undergoing in vitro fertilization (IVF) were associated with and increased the risk of breast cancer.RESULTS: Sixteen percent of the study subjects reported having experienced a fertility problem and 4% had used a fertility medication. Women who had used a fertility medication were not at significantly increased risk of breast cancer (odds ratio [OR] = 1.21; 95% confidence interval [CI] = 0.81-1.82) compared to non-users. Furthermore, there was no risk associated with a history of use of a fertility medication when the subjects were stratified by parity: (OR = 1.29; 95% CI = 0.83-2.01 for nulliparous women and OR = 0.81; 95% CI = 0.30-2.22 for parous women).CONCLUSIONS: The results of this study suggest that the use of fertility medications does not adversely affect the risk of breast cancer among BRCA mutation carriers. Given the small sizes of the exposed subgroups, these findings should be interpreted with caution and confirmatory studies are required.
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| 2. |
- McLaughlin, John R, et al.
(författare)
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Reproductive risk factors for ovarian cancer in carriers of BRCA1 or BRCA2 mutations: a case-control study
- 2007
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Ingår i: The Lancet Oncology. - 1474-5488. ; 8:1, s. 26-34
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Several of the known risk factors for ovarian cancer are thought to act through their effects on ovulation and the menstrual cycle, such as parity, breastfeeding, and use of oral contraceptives. We aimed to assess the effect of these three risk factors, and of tubal ligation, on the risk of ovarian cancer in women who carry a mutation in the BRCA1 or BRCA2 genes. METHODS: We did a matched case-control study in women who were found to carry a pathogenetic mutation in BRCA1 or BRCA2. Participants were derived from a population-based study of ovarian cancer in Ontario, Canada, and from an international registry of mutation carriers based in Toronto, ON, Canada. All participants completed a written questionnaire that detailed their reproductive history. Women with invasive ovarian cancer and controls were matched on year of birth, country of residence, mutation (BRCA1 or BRCA2), and history of breast cancer. The odds ratios and 95% CI for ovarian cancer were estimated with respect to use of oral contraceptives, parity, breastfeeding, and tubal ligation. FINDINGS: Questionnaires were completed by 799 women with a history of invasive ovarian cancer (670 with BRCA1 mutations, 128 with BRCA2 mutations, and one with a mutation in both genes), and controls were 2424 women without ovarian cancer (2043 with BRCA1 mutations, 380 with BRCA2 mutations, and one with a mutation in both genes). Use of oral contraceptives reduced the risk of ovarian cancer in carriers of BRCA1 mutations (odds ratio 0.56 [95% CI 0.45-0.71]; p<0.0001) and carriers of BRCA2 mutations (0.39 [0.23-0.66]; p=0.0004). Parity was associated with a reduced risk for carriers of BRCA1 mutations (0.67 [0.46-0.96]; p=0.03), but with an increased risk for those with BRCA2 mutations (2.74 [1.18-6.41]; p=0.02). Breastfeeding was associated with a reduced risk for carriers of BRCA1 mutations (0.74 [0.56-0.97]; p=0.03). An effect of similar magnitude was seen for carriers of BRCA2 mutations (0.72 [0.41-1.29]; p=0.27), but this was not statistically significant. The association with tubal ligation was not significant for carriers of BRCA1 mutations (0.80 [0.59-1.08]; p=0.15), or for carriers of BRCA2 mutations (0.63 [0.34-1.15]; p=0.13). INTERPRETATION: Oral contraceptives could be used as a means to prevent ovarian cancer in carriers of BRCA1 and BRCA2 mutations. The possible adverse effect of parity on ovarian-cancer risk in women with a BRCA2 mutation needs further study.
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