Observations of Second Primary Malignancy in Patients With Multiple Myeloma

BackgroundAdvances in the treatment of multiple myeloma have resulted in immunomodulatory (IMiD) agents becoming integral to the standard treatment armamentarium. IMiD agents are effective in the initial and relapsed settings of multiple myeloma. Three studies evaluating the duration of remission in maintenance lenalidomide vs. placebo reported an increased incidence of second primary malignancies in patients receiving maintenance therapy. The purpose of this study was to evaluate the incidence of second primary malignancies after IMiD exposure for standard induction and relapsed therapy in myeloma.Patients and MethodsA retrospective chart review was conducted at the Indiana University Simon Cancer Center in Indianapolis, Indiana. Patients were older than 18 years and had been diagnosed with multiple myeloma. Patients with a previous diagnosis of cancer were excluded. The primary objective was to assess the incidence of second primary malignancies in all patients. Secondary objectives included the type of malignancy, whether patients had been previously treated with IMiD therapy and the time from treatment initiation to diagnosis of a second malignancy.ResultsThree hundred twenty-five patients were reviewed and 279 were included in the study. Ten patients were diagnosed with a second primary malignancy (3.5%). Nine of the 10 patients were treated with IMiD therapy before diagnosis (P = .169). The mean time to diagnosis was 360 days for all patients.ConclusionThe incidence of second primary malignancy was not statistically significant in the IMiD-treated patients. Further long-term follow-up is needed to better assess the potential adverse events of these novel agents.