Subsequent malignancies among long‐term survivors of Hodgkin lymphoma and non‐Hodgkin lymphoma: a pooled analysis of German cancer registry data (1990–2012)

Summary The increased risk of subsequent primary malignancies ( SPM ) in survivors of adult‐onset Hodgkin lymphoma ( HL ) and non‐Hodgkin lymphoma ( NHL ) remains a challenging clinical problem worldwide. The German cancer registry database, pooled from 14 federal states, was used to calculate the standardized incidence ratio ( SIR ) and excess absolute risk ( EAR ) of SPM in 128 587 patients registered with first primary HL / NHL between 1990 and 2012. Conversely, SIR s were also calculated for a subsequent HL / NHL following other first cancers. The risk of developing SPM was significantly increased over twofold for HL survivors ( SIR  = 2·14, EAR  = 51·87 cases/10 000 person‐years) and 1·5‐fold for NHL survivors ( SIR  = 1·48, EAR  = 55·23) compared with the general German population. For solid cancers, SIR s were significantly elevated (1·6‐ and 1·4‐fold; respectively) and were highest (threefold) in patients below 30 years of age upon initial diagnosis. Overall, SIR s were consistently elevated for lip/oral cavity, colon/rectum, lung, skin melanoma, breast, kidney and thyroid. Significantly increased SIR s for oesophagus, stomach, liver, pancreas, testis, prostate, and brain/central nervous system were observed following NHL only. For certain SPM , SIR s remained significantly elevated more than 10 years following HL / NHL diagnosis. Positive reciprocal associations were demonstrated between HL / NHL and several solid cancers mentioned above; for some, common aetiological mechanisms seem plausible.