Background: With the improved survival of non-Hodgkin lymphoma (NHL) patients, development of second primary malignancy (SPM) has become an increasingly important issue in these long-term survivors.
Methods: We conducted a retrospective study to analyze NHL patients diagnosed between January 1997 and December 2010 in Taiwan. Standardized incidence ratios (SIRs) were applied to compare the risk of SPMs in NHL patients and the general population. Multivariate analysis was performed to determine the independent predictors of SPM.
Result: NHL patients have a significantly greater risk of developing SPM [SIR 1.43; 95 % confidence interval (CI) 1.32-1.55; p < 0.001). A significantly high SIR was noted for leukemia, myeloma, and neoplasms of the bone and soft tissue, thyroid, central nervous system, skin, stomach, head and neck, liver and biliary tract, and the lungs and mediastinum. Multivariate analysis revealed that age ≥60 years [hazard ratios (HR) 2.04], being male (HR 1.22), comorbidities of chronic obstructive pulmonary disease (HR 1.34), liver cirrhosis (HR 1.50), hepatitis C infection (HR 1.94) and therapy containing radiotherapy (HR 1.38) were the significant predictors for SPM occurrence. The median follow-up time and survival time were 3.37 and 9.45 years, respectively.
Conclusion: This Taiwanese population-based study provides updated data about the risk of SPM in NHL patients, demonstrating an approximately 1.5 time greater risk of SPM compared to the general population. A high risk of SPM for myeloma and hepatocellular carcinoma is unique to Asian patients.
Keywords: Cancer risk; Epidemiology; Non-Hodgkin lymphoma; Population study; Second malignancy.