Risk of second cancer in Hodgkin lymphoma survivors and influence of family history

Abstract

Purpose: Although advances in Hodgkin lymphoma (HL) treatment have led to improved disease-free survival, this has been accompanied by an increased risk of second cancers. We sought to quantify the second cancer risks and to investigate the impact of family history. Patients and Methods: Using the Swedish Family-Cancer Project Database, we identified 9,522 individuals with primary HL diagnosed between 1965 and 2012. We calculated standardized incidence ratios and cumulative incidence of second cancer in HL survivors and compared the standardized incidence ratios of lung, breast, colorectal, and all second cancers in HL survivors with and without a site-specific family history of cancer. Interactions between family history of cancer and HL treatment were evaluated under additive and multiplicative models. Results: Overall, the risk of a second cancer in HL survivors was increased 2.39-fold (95% CI, 2.29 to 2.53). The 30-year cumulative incidence of breast cancer in women diagnosed with HL at younger than 35 years of age was 13.8%. We observed no significant difference in cancer risk over successive time periods. The risk of all second cancers was 1.3-fold higher for HL survivors with a first-degree relative with cancer (P < .001), with 3.3-fold, 2.1-fold, and 1.8-fold differences shown for lung, colorectal, and breast cancers, respectively. Moreover, a greater than additive interaction between family history of lung cancer and HL treatment was shown (P = .03). Conclusion: HL survivorship is associated with a substantive risk of a second cancer. Notably, the risk is higher in individuals with a family history of cancer. This information should be used to inform risk-adapted therapy and to assist in screening to reduce long-term morbidity and mortality in patients with HL.