Purpose: To evaluate the risk of breast cancer (BC) and the contributing risk factors in women after supradiaphragmatic irradiation (SDI) for Hodgkin's lymphoma (HL).
Subjects and methods: Medical records of 248 women 60 years of age or less who received SDI for stage I/II HL between 1964 and 2001 at Massachusetts General Hospital were retrospectively reviewed.
Results: The median age at SDI was 26 years (range, 5.7-59.3). The median follow-up was 15.2 years (range, 0.1-41.3). In 36 patients, BC developed (bilaterally in 11 patients) at a median interval of 18.4 years (range, 4.3-33.8) after SDI. Based on data from the National Cancer Institute Surveillance, Epidemiology, and End Results program, the standardized morbidity ratio (SMR) for the first BC after SDI was 9.78 (95% confidence interval [CI], 4.64-18.11, p < 0.0001). The SMR of patients who received radiation before age of 30 years was 19.05 (95% CI, 12.33-28.13) compared with 4.64 (95% CI, 2.31-8.30) for patients aged 30 years or more at the time of treatment (p < 0.00003). Risk for BC was significantly higher 15 years or more after SDI compared with the risk during the first 15 years (p = 0.0026). None of HL characteristics or treatment details was associated with higher risk of BC after adjusting for age and calendar time.
Conclusions: Age at irradiation and time since therapy appear to be the only significant risk factors for development of BC after treatment of HL. The risk is significantly higher 15 years or more after radiation and for women treated before age 30 years. Long-term surveillance strategies are indicated for women at risk.