Risk assessment of second primary cancer according to histological subtype of non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) represents a heterogeneous group of diseases that are known to carry a considerable risk of second primary cancer (SPC). However, little attention has been paid to SPC risk assessment according to NHL subtypes. Data from 10 French population-based cancer registries were used to establish a cohort of 7546 patients with a first diagnosis of NHL (eight subtypes) between 1989 and 2004. Standardized incidence ratios (SIRs) of metachronous SPC were estimated. Among the 7546 patients diagnosed with a NHL, the overall SPC risk was 25% higher than that in the reference population (SIR = 1.25, 95% confidence interval 1.15-1.36). In univariate analysis, the SPC risk differed by lymphoma subtype. Interestingly, multivariate analysis showed that SPC risk did not differ significantly across NHL subtypes after adjustment for the other covariates (p = 0.786). Patients with NHL have an increased risk of SPC that is not influenced by the histological NHL subtype.