Outcomes of secondary primary malignancies among patients with diffuse large B-cell lymphoma.

Background: An increased risk of secondary primary malignancies (SPMs) has been shown in diffuse large B-cell lymphoma (DLBCL) patients after treatment. However, research on SPM outcomes in DLBCL patients is limited.

Methods: Utilizing the population-based Surveillance, Epidemiology, and End Results Registry (SEER), the authors examined the characteristics, overall survival (OS), and treatments in DLBCL patients who developed secondary cancers of the breast, prostate, lung, colon/rectum, bladder cancers, melanoma, myeloma, and acute leukemia. Each patient was matched by age, sex, race, year of diagnosis, and stage to 50 controls from a general population diagnosed with a non-DLBCL primary the cancer.

Results: Patients with antecedent DLBCL who developed lung cancer (37.3% vs. 18.3%, P < 0.001) or colon/rectum cancer (45.5% vs. 39.6%, P = 0.032) were more commonly diagnosed at an early stage. Compared with patients in the control group, patients with antecedent DLBCL who developed prostate cancer, melanoma, myeloma, and acute leukemia had significantly worse OS. Conversely, patients who developed lung cancer after their antecedent DLBCL diagnosis showed markedly better OS. Amongst patients with antecedent DLBCL aged over 60, intensive therapy was associated with improved OS compared to supportive care in those being treated for a SPM diagnosis of breast, prostate, lung, colon/rectum, melanoma or bladder cancer, but not myeloma or acute leukemia. The rates of surgical resection were the same between patients with antecedent DLBCL and those in the control group, except for lower prostatectomy rates and higher lobectomy rates among patients with antecedent DLBCL.

Conclusions: Our findings can assist clinicians in better understanding the survival outcomes of SPMs among patients with antecedent DLBCL while suggesting that long-term follow-up might be useful to detect DLBCL survivors who developed SPMs.