| 1. |
- Chang-Claude, Jenny, et al.
(author)
-
Age at menarche and menopause and breast cancer risk in the International BRCA1/2 Carrier Cohort Study
- 2007
-
In: Cancer Epidemiology Biomarkers and Prevention. - 1055-9965. ; 16:4, s. 740-746
-
Journal article (peer-reviewed)abstract
- Background: Early menarche and late menopause are important risk factors for breast cancer, but their effects on breast cancer risk in BRCA1 and BRCA2 carriers are unknown. Methods: We assessed breast cancer risk in a large series of 1,187 BRCA1 and 414 BRCA2 carriers from the International BRCA1/2 Carrier Cohort Study. Rate ratios were estimated using a weighted Cox-regression approach. Results: Breast cancer risk was not significantly related to age at menopause {hazard ratio [HR] for menopause below age 35 years, 0.60 [95% confidence interval (95% CI), 0.25-1.44]; 35 to 40 years, 1.15 [0.65-2.04]; 45 to 54 years, 1.02 [0.65-1.60]; ≥55 years, 1.12 [0.12-5.02], as compared with premenopausal women}. However, there was some suggestion of a reduction in risk after menopause in BRCA2 carriers. There was some evidence of a protective effect of oophorectomy (HR, 0.56; 95% CI, 0.29-1.09) and a significant trend of decreasing risk with increasing time since oophorectomy, but no apparent effect of natural menopause. There was no association between age at menarche and breast cancer risk, nor any apparent association with the estimated total duration of breast mitotic activity. Conclusions: These results are consistent with other observations suggesting a protective effect of oophorectomy, similar in relative effect to that in the general population. The absence of an effect of age at natural menopause is, however, not consistent with findings in the general population and may reflect the different natural history of the disease in carriers.
|
|
| 2. |
- Brohet, Richard M., et al.
(author)
-
Oral contraceptives and breast cancer risk in the international BRCA1/2 carrier cohort study: A report from EMBRACE, GENEPSO, GEO-HEBON, and the IBCCS Collaborating Group
- 2007
-
In: Journal of Clinical Oncology. - 1527-7755. ; 25:25, s. 3831-3836
-
Journal article (peer-reviewed)abstract
- Purpose Earlier studies have shown that endogenous gonadal hormones play an important role in the etiology of breast cancer among BRCA1/ 2 mutation carriers. So far, little is known about the safety of exogenous hormonal use in mutation carriers. In this study, we examined the association between oral contraceptive use and risk of breast cancer among BRCA1/ 2 carriers. Patients and Methods In the International BRCA1/ 2 Carrier Cohort study ( IBCCS), a retrospective cohort of 1,593 BRCA1/ 2 mutation carriers was analyzed with a weighted Cox regression analysis. Results We found an increased risk of breast cancer for BRCA1/ 2 mutation carriers who ever used oral contraceptives ( adjusted hazard ratio [ HR] = 1.47; 95% CI, 1.16 to 1.87). HRs did not vary according to time since stopping use, age at start, or calendar year at start. However, a longer duration of use, especially before first full- term pregnancy, was associated with an increased risk of breast cancer for both BRCA1 and BRCA2 mutation carriers ( 4 or more years of use before first full-term pregnancy: HR = 1.49 [ 95% CI, 1.05 to 2.11] for BRCA1 carriers and HR = 2.58 [ 95% CI, 1.21 to 5.49] for BRCA2 carriers). Conclusion No evidence was found among BRCA1/ 2 mutation carriers that current use of oral contraceptives is associated with risk of breast cancer more strongly than is past use, as is found in the general population. However, duration of use, especially before first full- term pregnancy, may be associated with an increasing risk of breast cancer among both BRCA1 and BRCA2 mutation carriers.
|
|
| 3. |
- Hill, Deirdre A., et al.
(author)
-
Breast cancer risk following radiotherapy for Hodgkin lymphoma : modification by other risk factors
- 2005
-
In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 106:10, s. 3358-65
-
Journal article (peer-reviewed)abstract
- The importance of genetic and other risk factors in the development of breast cancer after radiotherapy (RT) for Hodgkin lymphoma (HL) has not been determined. We analyzed data from a breast cancer case-control study (105 patients, 266 control subjects) conducted among 3 817 survivors of HL diagnosed at age 30 years or younger in 6 population-based cancer registries. Odds ratios (ORs) and excess relative risks (ERRs) were calculated using conditional regression. Women who received RT exposure (> or = 5 Gy radiation dose to the breast) had a 2.7-fold increased breast cancer risk (95% confidence interval (CI) 1.4-5.2), compared with those given less than 5 Gy. RT exposure (> or = 5 Gy) was associated with an OR of 0.8 (95% CI, 0.2-3.4) among women with a first- or second-degree family history of breast or ovarian cancer, and 5.8 (95% CI, 2.1-16.3) among all other women (interaction P = .03). History of a live birth appeared to increase the breast cancer risk associated with RT among women not treated with ovarian-damaging therapies. Breast cancer risk following RT varied little according to other factors. The additional increased relative risk of breast cancer after RT for HL is unlikely to be larger among women with a family history of breast or ovarian cancer than among other women.
|
|
| 4. |
- Travis, Lois B., et al.
(author)
-
Cumulative absolute breast cancer risk for young women treated for Hodgkin lymphoma
- 2005
-
In: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 97:19, s. 1428-37
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Many women develop breast cancer after treatment for Hodgkin lymphoma (HL) at a young age. We estimated this future risk, taking into account age and calendar year of HL diagnosis, HL treatment information, population breast cancer incidence rates, and competing causes of death. METHODS: Relative risks of breast cancer for categories defined by radiation dose to the chest (0, 20- < 40 Gy, or > or = 40 Gy) and use of alkylating agents (yes or no) were estimated from a case-control study conducted within an international population-based cohort of 3817 female 1-year survivors of HL diagnosed at age 30 years or younger from January 1, 1965, through December 31, 1994. To compute cumulative absolute risks of breast cancer, we used modified standardized incidence ratios to relate cohort breast cancer risks to those in the general population, enabling application of population-based breast cancer rates, and we allowed for competing risks by using population-based mortality rates in female HL survivors. RESULTS: Cumulative absolute risks of breast cancer increased with age at end of follow-up, time since HL diagnosis, and radiation dose. For an HL survivor who was treated at age 25 years with a chest radiation dose of at least 40 Gy without alkylating agents, estimated cumulative absolute risks of breast cancer by age 35, 45, and 55 years were 1.4% (95% confidence interval [CI] = 0.9% to 2.1%), 11.1% (95% CI = 7.4% to 16.3%), and 29.0% (95% CI = 20.2% to 40.1%), respectively. Cumulative absolute risks were lower in women treated with alkylating agents. CONCLUSIONS: Breast cancer projections varied considerably by type of HL therapy, time since HL diagnosis, and age at end of follow-up. These estimates are applicable to HL survivors treated with regimens of the past and can be used to counsel such patients and plan management and preventive strategies. Projections should be used with caution, however, in patients treated with more recent approaches, including limited-field radiotherapy and/or ovary-sparing chemotherapy.
|
|
