Thyroid abnormalities in patients treated with lenalidomide for hematological malignancies: results of a retrospective case review.

Lenalidomide is an antiangiogenic drug associated with hypothyroidism. We describe a case-series of lenalidomide use in hematological cancers and the prevalence of thyroid abnormalities. We reviewed medical records of patients treated with lenalidomide at a single center form 2005 to 2010 and extracted demographic, clinical, and laboratory data. Of 170 patients with confirmed lenalidomide use (age 64.9 ± 15 years), 148 were treated for multiple myeloma and 6% had thyroid abnormalities attributable only to lenalidomide. In patients with a previous diagnosis of thyroid dysfunction, the addition of lenalidomide therapy was associated with a higher incidence of subsequent TFTF abnormality (17%) as compared to patients with no previous diagnosis of thyroid dysfunction (6%) (P=0.0001). Many patients (44%) with pre-existing disease and a change in thyroid function before or while on lenalidomide had no further follow-up of their thyroid abnormalities, Of 20 patients who did not undergo any thyroid function testing either before starting or while on lenalidomide for a median of 9.4 months (± 6.5), 35% developed new symptoms compatible with hypothyroidism, including worsened fating, constipation or cold intolerance. Symptoms of thyroid dysfunction overlap with side effects of lenalidomide. Thyroid hormone levels are not regularly evaluated in patients on lenalidomide. While on this treatment, thyroid abnormalities can occur in patients with no previous diagnoses and in patients with pre-existing abnormalities. Because symptoms of thyroid dysfunction could be alleviated by appropriate treatment, thyroid function should be evaluated during the course of lenalidomide to improve patients quality of life.