The practice of thyroid monitoring in patients treated with lenalidomide for hematological malignancies: A single-center retrospective analysis.

Abstract

e14535 Background: Thyroid dysfunction in the form of both hypothyroidism and hyperthyroidism is a known fact and is seen in 5-10 % of patients treated with Lenalidomide. Since the potential impact of thyroid disease on a patient being treated for malignancies can be devastating, surveillance evaluation of thyroid function has been recommended on a bi-monthly basis. This single center retrospective analysis is an effort to understand if this recommendation is practiced by hematologists. Methods: Data for this retrospective chart review was extracted from electronic medical records. 225 patients who received Lenalidomide from the year January 2019 to October 2022 were included. Thyroid monitoring was estimated through thyroid stimulating hormone (TSH) if done and was further classified as baseline (TSH before lenalidomide initiation) versus three months. Abnormal thyroid testing was perceived as TSH outside of our institute’s normal range (0.40-4.0 uIU/mL). Any other risk factors of developing thyroid disease (neck radiation exposure, autoimmune disorders or other drugs contributing to thyroid disfunction) were also recorded. Descriptive statistics with interquartile ranges and frequencies were analyzed. Results: Doses of Lenalidomide used ranged between 5 and 25 mg, over a time period ranging between 1 and 48 months. Reasons for discontinuation of Lenalidomide included bone marrow suppression (N=32, 14%), neuropathy (N=14, 0.06%), intolerable fatigue (N=7, 0.03%) and one patient had concerns for drug induced hypothyroidism. Seven patients were found to have pre-existing thyroid disease, which was well controlled with replacement before initiation of Lenalidomide. 52% had a baseline TSH documented prior to initiation of treatment, while only 18 patients (0.08%), had three monthly thyroid monitoring. Conclusions: Lenalidomide caused hypothyroidism was seen in one of our patients, however 48% never had a TSH documented, while 99.2% were not monitored as per recommendations. This study reflects on the principle of “primum non nocere” and adequate treatment of missed thyroid anomalies in patients treated with lenalidomide can improve quality of life. We recommend hard reminders of bi-monthly TSH monitoring through electronic medical record, for patients receiving Lenalidomide which has been initiated in our institute post this study.