Breast cancer in women following supradiaphragmatic irradiation for Hodgkin's disease

Purpose: In women treated with supradiaphragmatic irradiation for Hodgkin's disease (HD) the relative risk (RR) of breast cancer (BC) has been reported to be elevated, particularly in younger women. A retrospective chart review was conducted to investigate the incidence of BC and to describe the characteristics of these cases. Based on these results, predictions were made regarding the future incidence of breast cancer in this patient population, and surveillance strategies are outlined. Patients and Methods: Charts from 1965 through 1990 were reviewed at the Princess Margaret Hospital to include women less than or equal to 30 years who were treated with supradiaphragmatic irradiation for HD. Results: Of the 427 women with a mean follow-up of 12.3 years, 15 subsequently developed BC. The median age at BC diagnosis was 41 years (range: 30-52) and the median interval from irradiation was 17 years (9-25). Laterality was equally divided, and 50% of the tumors were located in the inner quadrant of the breast. Two women developed bilateral metachronous tumors. In this cohort, the RR of BC is 10.6 (95% confidence interval 5.8-17). It is predicted that in our patient population there will be a total of 22, 32, and 39 cases of BC by the years 2000, 2005, and 2010, respectively. Conclusion: Compared to women in the general population, young women irradiated for HD have a 10-fold higher risk of developing BC. In this specific patient group, we are able to predict the number of BC cases expected in the forthcoming years. Hopefully, improved surveillance will enable early detection, timely treatment, and improved prognosis for these at-risk women.