Trends in the Risks of Secondary Cancers in Patients With Hodgkin Lymphoma

Hodgkin lymphoma (HL) patients have excellent outcomes but second cancers (SCs) gain importance with survivorship. The Surveillance, Epidemiology, and End Results database was used to determine the risk of SCs. The overall risk of SCs in HL patients declined over time but the risk of SCs at several organ sites remained the same, necessitating the need for ongoing targeted surveillance. Introduction: The present study analyzed the trends in secondary cancer (SC) risks among Hodgkin lymphoma (HL) patients in the United States. Materials and Methods: Patients with HL diagnosed from 1973 to 2014 were identified from the Surveillance, Epidemiology, and End Results database. We compared the risk of SCs in HL patients relative to the risk in the US general population across 3 periods: 1973 to 1986, 1987 to 2000, and 2001 to 2014 to study the effect of treatment practices on the development of SCs. Results: In a follow-up study of 23,864 HL survivors for 284,730 person-years, 3260 SCs were diagnosed with a standardized incidence ratio (SIR) of 1.97 (95% confidence interval [CI], 1.9-2.04). A statistically significant decrease was found in the overall SIRs of SCs diagnosed in HL patients from 1987 to 2000 (SIR, 1.82; 95% CI, 1.72-1.93) and from 2001 to 2014 (SIR, 1.66; 95% CI, 1.51-1.82) relative to patients with SCs diagnosed from 1973 to 1986 (SIR, 2.24; 95% CI, 2.13-2.35). The decline in the overall SIR mostly resulted from declines in digestive tract and breast cancers. The SIRs of most other solid tumors and hematologic malignancies did not decrease. After adjusting for age, gender, and race, patients with a diagnosis from 1973 to 1986 had a 12% greater risk of developing SCs (hazard ratio, 1.12; 95% CI, 1.03-1.23; P =.01) compared with the patients with a diagnosis from 1987 to 2000. Conclusion: Although the overall risk of SCs in patients with HL declined after modifications in HL treatment, the risk did not change significantly at most individual sites. Thus, close follow-up with active surveillance for SCs is crucial for long-term survivors of HL.