Background: Long-term survivors of successfully treated Hodgkin's disease (HD) are at risk for late complications. Among these, secondary solid tumors are most serious because they are often fatal. The aim of this retrospective analysis was to assess the incidence, relative risk and risk factors of secondary solid tumors in HD patients registered in the database of the German Hodgkin Lymphoma Study Group (GHSG).
Patients and methods: From 1983 to 1998, the GHSG conducted three generations of clinical trials for early, intermediate and advanced stage HD (HD1-HD9) involving a total of 5367 patients. Data on incidence, risk factors and relative risk were updated in March 2003.
Results: A total of 127 patients with secondary solid tumors were identified. Among these, lung cancer (23.6%), colorectal cancer (20.5%) and breast cancer (10.2%) were the most frequent. After a median follow-up of 72 months the cumulative risk of developing a solid tumor was 2%, with an overall relative risk (RR) of 2.4 (lung cancer, 3.8; colorectal cancer, 3.2; breast cancer, 1.9). For most patients (n=67; 52.8%) developing a secondary solid tumor, treatment modality consisted of chemotherapy combined with radiotherapy in extended field technique (RR = 3.3).
Conclusions: With a median follow-up of 72 months, there were 127 patients developing solid tumors out of a total of 5367 HD patients treated in the GHSG studies HD1-HD9. The cumulative risk of 2% is expected to increase over time due to the rather short median observation time and slow progression of solid malignancies.