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

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, SIRs 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, SIRs 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, SIRs were consistently elevated for lip/oral cavity, colon/rectum, lung, skin melanoma, breast, kidney and thyroid. Significantly increased SIRs for oesophagus, stomach, liver, pancreas, testis, prostate, and brain/central nervous system were observed following NHL only. For certain SPM, SIRs 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.