Endocrine Abstracts

Background: In the last years, Pembrolizumab has been used to treat solid and lymphatic neoplasms, showing improved patients’ survival. Due to its mechanism of action, Pembrolizumab may be responsible of several immune-related adverse events (irAEs). The most frequent endocrine-irAEs reported are thyroid diseases.

Aims: The aim of this study was to evaluate differences in thyroid disease incidence and presentation between patients treated for lung cancer and those for lymphomas.

Materials and methods: Data of patients treated with flat dose of Pembrolizumab (200 mg/3 weeks) for lymphoma and for lung cancer, attending the Institute of Hematology Seràgnoli and the Oncology Unit of Bologna respectively, were retrospectively collected. Blood tests for thyroid function were drawn at baseline and before each injections.

Results: We included 69 patients, 37 with lung cancer (26 adenocarcinoma; 11 squamous cell carcinoma) and 32 with lymphoma (19 nodular sclerosis Hodgkin lymphoma; 13 primary mediastinal B-cell lymphoma).Pembrolizumab was administered in both cancer population for a similar amount of time (lung cancer: median of 21 weeks, lymphoma median of 25; P = 0.330). The follow up was different according to the evolution of cancer type(lung cancer median of 21 weeks, range: 6–111; lymphomas for 115 weeks, range: 4–208; P < 0.001). Patients with lung cancer were older than those with lymphoma (median: 33 years, range: 18–68 vs median: 70, range: 50–82; P < 0.001). Thyroid disease prevalence was similar (10.8% for lung cancer and 9.4% for lymphoma, P = 0.844). In particular, 3 patients developed thyrotoxicosis and 1 hypothyroidism in the lung cancer population, while 1 thyrotoxicosis and 2 hypothyroidisms were found in the lymphoma ones. In all patients, thyrotoxicosis was an early event, occurring between the 2nd and 5th administration of Pembrolizumab, while hypothyroidism arose later, between the 7th and 14th cycle. The clinical presentation and progress of thyroid diseases were equal between the two cancer populations. Thyrotoxicosis was asymptomatic and reversible, whereas the hypothyroidism was clinically mild (grade 2) but permanent, requiring long-life replacement therapy. In all subjects Pembrolizumab was continued despite thyropaties onset. No differences in TSH values before Pembrolizumab adminstration were found between patients who developed thyropathies and the remaining patients (P = 1.000 for lung cancer and P = 0.637 for lymphoma).

Conclusion: No differences for frequency, characteristics and evolution of thyroid diseases were shown in patients treated with Pembrolizumab in solid and hematologic malignancies. The type of tumours and age at treatment are not associated with the development of drug-induced endocrine adverse events.