Roles of radiation dose, chemotherapy, and hormonal factors in breast cancer following Hodgkin's disease.

Background: Female survivors of Hodgkin's disease (HD) have a strongly elevated risk of breast cancer, but factors responsible for the increased risk are not well known.

Methods: We investigated the effects of radiation dose, chemotherapy (CT), and reproductive factors on breast cancer risk in a nested case-control study in The Netherlands in a cohort of 770 female patients who had been diagnosed with HD before age 41. Detailed treatment information and data on reproductive factors were collected for 48 case patients who developed breast cancer 5 or more years after diagnosis of HD and 175 matched control subjects.