Radiation Therapy for Hodgkin's Disease and Breast Cancer
The Frequently Asked Question document you had mentioned addressed the issues surrounding the etiology of diabetes and hypothyroidism. The possibility of radiation therapy being at the root of those two problems was discussed to directly respond to the inquiry.
The question of second malignancies in patients treated for Hodgkin's disease in their adolescence is a complicated one. Is there a higher propensity for patients who have had Hodgkin's disease to have another cancer, is it because of the treatment they received, or is it for both reasons that these patients have a higher risk?
Regardless, a preponderance of data demonstrate an increased rate of second malignancies in patients treated for Hodgkin's disease with radiation with or without chemotherapy. The types of cancers include but are not limited to breast cancer, lung cancer, non-Hodgkins lymphoma, sarcomas and leukemias (mostly chemotherapy associated). The latent period is over 10 or leukemias (6 . The estimated actuarial risk of any second neoplasms at 15 years after diagnosis is approximately 5 cancer risk of 2% estimated 20 years from diagnosis for all female Hodgkin's disease patients (treated in child- or adulthood). Data from Stanford University on nearly 700 patients treated for childhood Hodgkin's disease suggest a 9% risk of developing breast cancer at 20 years from diagnosis. The New England Journal of Medicine published a review on over 1300 patients with childhood Hodgkin's treated before the age of 16 years. They described the breast cancer risk to be as high as 35% by the age of 40 years, which is higher than other reports.
The risk of second malignancies is at least 2 if they were treated during childhood or adolescence. Recommendations are for routine follow-up on an every 6 month basis (at the very least) along with monthly breast self-examinations. Screening exams should begin earlier than the recommended time period for average women.
Here are some references for a more in depth review of the subject: