e14134 Background: Immune-related endocrine dysfunction is unique to immunotherapy (IT). We aimed to explore the clinical parameters associated with development of thyroid disorder (TD) in patients receiving IT and their outcome. Methods: We designed a retrospective study of patients treated with anti-CTLA4 and/or anti-PD1/PDL1 IT at Cook County Hospital, Chicago between January 2015 to January 2018. Patients with incomplete charts and those who received less than two cycles of IT were excluded. Demographics, clinical and pathologic data were recorded at the time of diagnosis and prior to start of IT. Pearson Chi-square, independent sample t-test and logistic regression were used for data analysis. Results: We included 104 patients in the study, out of whom 66 were male and 38 were female. Most common diagnosis was non-small cell lung cancer (42.4%) followed by squamous cell cancer of head and neck (21.2%), renal cell cancer (12.5%), small cell lung cancer (12.5%) and melanoma (8.7%). Majority of patients (91.4%) had metastasized and were treated with either Nivolumab (71.1%) or Pembrolizumab (21.2%) in the 2nd (50%) or 3rd line (29.8%) setting. Twenty-eight patients developed TD while on IT, out of whom, 13 developed hypothyroidism, 12 developed hyperthyroidism followed by hypothyroidism and 3 developed hyperthyroidism. TD developed between 1st to 6th cycle of IT in 96.5% patients. Older age (p-0.009), history of radiation (RT) to neck (p-0.007), history of RT to chest (p-0.015), history of venous thrombosis (p-0.007) and higher thyroid stimulating hormone (TSH) level (17.76±35.67) prior to starting IT (p-0.029) were significantly associated with TD. Multivariate logistic regression showed that history of RT to neck was a significant predictor of developing TD after adjustment for age, race and sex (adjusted OR 9.64, 95% CI 1.88-49.36, p-0.007). No patient reported thyroid related symptom and IT was continued uninterrupted in all patients. Levothyroxine was the drug of choice for treating hypothyroidism. No patient received steroids or antithyroid medications. Conclusions: History of radiation therapy to neck is significantly associated with development of thyroid dysfunction in patients receiving immunotherapy. Thyroid replacement therapy is sufficient to bring down the levels of TSH and immunotherapy need not be interrupted.
Development of thyroid dysfunction is associated with clinical response to PD-1 blockade treatment in patients with advanced non-small cell lung cancer
