Is radioactive iodine- 131 treatment related to the occurrence of non-synchronous second primary malignancy in patients with differentiated thyroid cancer?

Objective Much controversy relates to the risk of non-synchronous second primary malignancies (NSSPM) after radioactive iodine treatment (RAI-131) in differentiated thyroid cancer (DTC) patients. This study evaluated the relationship between RAI-131 and NSSPM in DTC survivors with long-term follow-up. Materials and methods Retrospective analysis of 413 DTC cases was performed; 252 received RAI-131 and 161 were treated with thyroidectomy alone. Exclusion criteria were: prior or synchronous non-thyroidal malignancies (within the first year), familial syndromes associated to multiple neoplasms, ionizing radiation exposure or second tumors with unknown histopathology. Results During a mean follow-up of 11.0 ± 7.5 years, 17 (4.1%) patients developed solid NSSPM. Patients with NSSPM were older than those without (p = 0.02). RAI-131 and I-131 cumulative activity were similar in patients with and without NSSPM (p = 0.18 and p = 0.78, respectively). Incidence of NSSPM was 5.2% in patients with RAI-131 treatment and 2.5% in those without RAI-131 (p = 0.18). Using multivariate analysis, RAI-131 was not significantly associated with NSSPM occurrence (p = 0.35); age was the only independent predictor (p = 0.04). Under log rank statistical analysis, after 10 years of follow-up, it was observed a tendency of lower NSSPM-free survival among patients that received RAI-131 treatment (0.96 vs . 0.87; p = 0.06), what was not affected by age at DTC diagnosis. Conclusion In our cohort of DTC survivors, with a long-term follow-up period, RAI-131 treatment and I-131 cumulative dose were not significantly associated with NSSPM occurrence. A tendency of premature NSSPM occurrence among patients treated with RAI-131 was observed, suggesting an anticipating oncogenic effect by interaction with other risk factors.

A Case of Secondary Primary Malignancy after Lenalidomide Therapy for Multiple Myeloma / 대한내과학회지

Lenalidomide, an orally administered immune-modulating drug, has several mechanisms of action against multiple myeloma (MM). However, the mechanisms of action of immune-modulating drugs are not understood completely. Lenalidomide maintenance therapy prolongs the time to progression and increases the overall survival in patients with MM. However, secondary primary malignancy (SPM) has been noted as a serious adverse event in patients with MM treated with lenalidomide. Lenalidomide treatment is not covered by insurance. Consequently, physicians have little experience with the adverse events of lenalidomide treatment in patients with MM. Here, we describe a case of breast cancer after lenalidomide treatment for MM. To our knowledge, this is the first report of a lenalidomide-associated SPM in Korea. The risk factors associated with lenalidomide-associated SPM should be considered carefully when implementing chemotherapy regimens in patients with MM.