Effect of systemic adjuvant treatment on risk for contralateral breast cancer in the women's environment, cancer and radiation epidemiology study Journal Article


Authors: Bertelsen, L.; Bernstein, L.; Olsen, J. H.; Mellemkjær, L.; Haile, R. W.; Lynch, C. F.; Malone, K. E.; Anton-Culver, H.; Christensen, J.; Langholz, B.; Thomas, D. C.; Begg, C. B.; Capanu, M.; Ejlertsen, B.; Stovall, M.; Boice, J. D.; Shore, R. E.; Bernstein, J. L.; Boice, J. D. Jr; Børresen-Dale, A. L.; Concannon, P.; Gatti, R. A.; Langholz, B. M.; Rosenstein, B.; Thompson, W. D.; Liang, X.; Wolitzer, A.; Seminara, D.; Donnelly-Allen, L.; DeWall, J.; Epstein, N.; Largent, J.; Smith, S.; Whittemore, A.
Article Title: Effect of systemic adjuvant treatment on risk for contralateral breast cancer in the women's environment, cancer and radiation epidemiology study
Abstract: Background: Results from randomized trials indicate that treatment with tamoxifen or chemotherapy for primary breast cancer reduces the risk for contralateral breast cancer. However, less is known about how long the risk is reduced and the impact of factors such as age and menopausal status. Methods: The study included 634 women with contralateral breast cancer (case patients) and 1158 women with unilateral breast cancer (control subjects) from the Women's Environment, Cancer and Radiation Epidemiology Study. The women were younger than age 55 when they were first diagnosed with breast cancer during 1985-1999. Rate ratios (RRs) and 95% confidence intervals (CIs) for contralateral breast cancer after treatment with chemotherapy or tamoxifen were assessed by multivariable adjusted conditional logistic regression analyses. Results: Chemotherapy was associated with a lower risk for contralateral breast cancer (RR = 0.57, 95% CI = 0.42 to 0.75) than no chemotherapy. A statistically significant association between chemotherapy and reduced risk for contralateral breast cancer persisted up to 10 years after the first breast cancer diagnosis and was stronger among women who became postmenopausal within 1 year of the first breast cancer diagnosis (RR = 0.28, 95% CI = 0.11 to 0.76). Tamoxifen use was also associated with reduced risk for contralateral breast cancer (RR = 0.66, 95% CI = 0.50 to 0.88) compared with no use, and the association was statistically significant for 5 years after the first diagnosis. Conclusion: The associations between chemotherapy and tamoxifen treatment and reduced risk for contralateral breast cancer appear to continue for 10 and 5 years, respectively, after the initial breast cancer is diagnosed. Ovarian suppression may have a role in the association between chemotherapy and reduced risk for contralateral breast cancer. © The Author 2007. Published by Oxford University Press. All rights reserved.
Keywords: adult; controlled study; treatment outcome; middle aged; unclassified drug; major clinical study; case control study; case-control studies; doxorubicin; fluorouracil; cancer risk; adjuvant therapy; chemotherapy, adjuvant; radiotherapy, adjuvant; research design; methotrexate; methodology; antineoplastic agent; cancer diagnosis; breast cancer; antineoplastic combined chemotherapy protocols; aromatase inhibitor; cyclophosphamide; drug effect; breast neoplasms; risk assessment; confidence interval; ovary; statistical significance; confounding factors (epidemiology); adjuvant chemotherapy; breast tumor; drug derivative; tamoxifen; epirubicin; multivariate analysis; neoplasms, second primary; antineoplastic agents, hormonal; second cancer; epidemiology; menopause; logistic regression analysis; testosterone; antineoplastic hormone agonists and antagonists; cmf regimen; progesterone; selective estrogen receptor modulator; caf protocol 2; estrogen receptor modulators
Journal Title: JNCI: Journal of the National Cancer Institute
Volume: 100
Issue: 1
ISSN: 0027-8874
Publisher: Oxford University Press  
Date Published: 2008-01-01
Start Page: 32
End Page: 40
Language: English
DOI: 10.1093/jnci/djm267
PUBMED: 18159070
PROVIDER: scopus
DOI/URL:
Notes: --- - "Cited By (since 1996): 15" - "Export Date: 17 November 2011" - "CODEN: JNCIA" - "Source: Scopus"
Altmetric Score
MSK Authors
  1. Colin B Begg
    241 Begg
  2. Marinela Capanu
    212 Capanu
  3. Jonine L Bernstein
    104 Bernstein