Secondary Malignancies Following Treatment for Hodgkin's Lymphoma in Childhood and Adolescence.

Background: About 155 persons under age 18 develop Hodgkin's lymphoma (HL) in Germany every year. More than 90% survive at least 20 years. They may, however, suffer from late sequelae of treatment, including secondary malignant neoplasia (SMN). Methods: 2548 patients from the German, Austrian, and Swiss pediatric Hodgkin's lymphoma studies that were conducted over the period 1978-2002 were asked every 2-3 years about possible late sequelae of treatment, either directly or through their physicians. The documented cases of SMN were analyzed for cumulative incidence, standardized incidence rates (SIR), and absolute excess risk (AER). Results: 147 cases of SMN were diagnosed in 138 of the 2548 patients, including 47 cases of thyroid cancer, 37 of breast cancer, and 15 of hematopoietic neoplasia. The cumulative incidence of SMN at 20, 25, and 30 years was 7%, 11.2%, and 18.7%, respectively. These percentages are rather low compared to other international studies. For all types of SMN, the SIR was 9.1 and the AER was 16.8. Among the 123 patients with secondary solid tumors, 105 (85%) had a tumor in the irradiated region. Conclusion: Survivors of pediatric HL must be informed about the risk of late sequelae of treatment for HL, including SMN in the irradiated region, and that they will need regular follow-up examinations. In the future, radiotherapy for children and adolescents should be further reduced or entirely avoided.