Breast cancer in young women after treatment for Hodgkin's disease during childhood or adolescence--an observational study with up to 33-year follow-up.

BACKGROUND: The treatment of Hodgkin's disease (HD; also called Hodgkin's lymphoma) in children and adolescents with radiotherapy and chemotherapy leads to high survival rates but has a number of late effects. The most serious one is the development of a secondary malignant tumor, usually in the field that was irradiated. In women, breast cancer can arise in this way. METHOD: Data on the occurrence of secondary breast cancer (sBC) were collected from 590 women who were treated in five consecutive pediatric HD treatment studies in the years 1978-1995 and then re-evaluated in a late follow-up study after a median interval of 17.8 years (maximum, 33.7 years). Information was obtained from 1999 onward by written inquiry to the participants and their treating physicians. The cumulative incidence of sBC was calculated by the Gooley method. RESULTS: By July 2012, sBC had been diagnosed in 26 of 590 female HD patients; the breast cancer was in the irradiated field in 25 of these 26 patients. Their age at the time of treatment for HD was 9.9 to 16.2 years (the pubertal phase), and sBC was discovered with a median latency of 20.7 years after HD treatment (shortest latency, 14.3 years) and at a median age of 35.3 years (youngest age, 26.8 years). The radiation dose to the supradiaphragmatic fields ranged from 20 to 45 Gy. The cumulative incidence for sBC 30 years after treatment for HD was 19% (95% confidence interval, 12% to 29%). For women aged 25 to 45 in this series, the frequency of breast cancer was 24 times as high as in the corresponding normal population. CONCLUSION: Women who were treated for HD in childhood or adolescence have an increased risk of developing breast cancer as young adults. The risk is associated with prior radiotherapy and with the age at which it was administered (the pubertal phase). Because of these findings, a structured breast cancer screening project for this high-risk group has been initiated in collaboration with the German Consortium for Hereditary Breast and Ovarian Cancer (Deutsches Konsortium für familiären Brust- und Eierstockkrebs).