Risk for malignancies of infectious etiology among adult survivors of specific non-Hodgkin lymphoma subtypes.

Infectious agents have been identified in the etiology of certain non-Hodgkin lymphoma (NHL) subtypes and solid tumors. The impact of this shared etiology on risk for second cancers in NHL survivors has not been comprehensively studied. We used US population-based cancer registry data to quantify risk of solid malignancies associated with infectious etiology among 127 044 adult 1-year survivors of the 4 most common NHL subtypes diagnosed during 2000 to 2014 (mean follow-up, 4.5-5.2 years). Compared with the general population, elevated risks for liver, stomach, and anal cancers were observed among diffuse large B-cell lymphoma (DLBCL) survivors (standardized incidence ratio [SIR], 1.85; 95% confidence interval [CI], 1.46-2.31; SIR, 1.51; 95% CI, 1.16-1.94; SIR, 3.71; 95% CI, 2.52-5.27, respectively) and marginal zone lymphoma (MZL; SIR, 1.98; 95% CI, 1.34-2.83; SIR, 2.78; 95% CI, 2.02-3.74; SIR, 2.36; 95% CI, 1.02-4.64, respectively) but not follicular lymphoma or chronic lymphocytic leukemia/small lymphocytic lymphoma. Anal cancer risk was particularly elevated among DLBCL survivors with HIV (SIR, 68.34; 95% CI, 37.36-114.66) vs those without (SIR, 2.09; 95% CI, 1.22-3.34). The observed patterns are consistent with shared associations between these cancers and hepatitis C virus, Helicobacter pylori, and HIV, respectively. In contrast, risks for cervical and oropharyngeal/tonsil cancers were not elevated among survivors of any NHL subtype, possibly because of the lack of NHL association with human papillomavirus or population-wide screening practices (for cervical cancer). In summary, patterns of elevated second cancer risk differed by NHL subtype. Our results suggest shared infectious etiology has implications for subsequent cancer risks among DLBCL and MZL survivors, which may help inform surveillance for these survivors.