Dose to the Contralateral Breast From Radiotherapy and Risk of Second Primary Breast Cancer in the WECARE Study

Journal Article · Fri Nov 14 23:00:00 EST 2008 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2008.02.040· OSTI ID:21172452

Stovall, Marilyn ^[1]; Smith, Susan A ^[1]; Langholz, Bryan M ^[2]; Boice, John D ^[3]; Shore, Roy E ^[4]; Andersson, Michael ^[5]; Buchholz, Thomas A ^[6]; Capanu, Marinela ^[7]; Bernstein, Leslie ^[8]; Lynch, Charles F ^[9]; Malone, Kathleen E ^[10]; Anton-Culver, Hoda ^[11]; Haile, Robert W ^[2]; Rosenstein, Barry S ^[12]

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1. Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)
2. Department of Preventive Medicine, University of Southern California, Los Angeles, CA (United States)
3. International Epidemiology Institute, Rockville, MD (United States)
4. Radiation Effects Research Foundation (RERF), Hiroshima (Japan)
5. Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen (Denmark)
6. Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)
7. Department of Statistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)
8. Department of Cancer Etiology, City of Hope National Medical Center, Duarte, CA (United States)
9. Department of Epidemiology, University of Iowa, Iowa City, IA (United States)
10. Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (United States)
11. Department of Epidemiology, University of California, Irvine, CA (United States)
12. Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States)

Purpose: To quantify the risk of second primary breast cancer in the contralateral breast (CB) after radiotherapy (RT) for first breast cancer. Methods and Materials: The study population included participants in the Women's Environmental, Cancer, and Radiation Epidemiology study: 708 cases (women with asynchronous bilateral breast cancer) and 1399 controls (women with unilateral breast cancer) counter-matched on radiation treatment. Participants were <55 years of age at first breast cancer. Absorbed doses to quadrants of the CB were estimated. Rate ratios (RR) and 95% confidence intervals (CI) were calculated using multivariable-adjusted conditional logistic regression models. Results: Across all patients, the mean radiation dose to the specific quadrant of the CB tumor was 1.1 Gy. Women <40 years of age who received >1.0 Gy of absorbed dose to the specific quadrant of the CB had a 2.5-fold greater risk for CB cancer than unexposed women (RR = 2.5, 95% CI 1.4-4.5). No excess risk was observed in women >40 years of age. Women <40 years of age with follow-up periods >5 years had a RR of 3.0 (95% CI 1.1-8.1), and the dose response was significant (excess RR per Gy of 1.0, 95% CI 0.1-3.0). Conclusions: Women <40 years of age who received a radiation dose >1.0 Gy to the CB had an elevated, long-term risk of developing a second primary CB cancer. The risk is inversely related to age at exposure and is dose dependent.

• OSTI ID: 21172452
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 72; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
EPIDEMIOLOGY
MAMMARY GLANDS
PATIENTS
RADIATION DOSES
RADIATION HAZARDS
RADIOTHERAPY
WOMEN