The aim of the study was to assess the occurrence and nature of immune-related endocrine adverse events (irAEs) among patients with non-small-cell lung cancer (NSCLC) treated with nivolumab.
Methods: The study group included 35 patients (15 women, 20 men, 65.8 ± 7.1 years) with NSCLC in stage IIIB (n = 16, 45.7%) and IV (n = 19,54.3%) who were treated with nivolumab.
Results: Of the studied patients, 34.3% (n = 12) developed endocrine irAEs (irAE group): 22.9% (n = 8) hyperthyroidism and 8.6% (n = 3) hypothyroidism, and in one case, hypophysitis was observed. The median irAEs onset time was 2 months. In the group of patients with thyroid disorders, permanent hypothyroidism eventually developed in 58.3%. The severity of the analyzed irAEs ranged from mild to moderate (Grade 1-2); the case of hypophysitis was estimated as Grade 3. The comparison of progression-free survival time (PFS) between the two groups showed longer PFS in patients in the irAE group (p = 0.021). Patients with irAE were treated significantly longer with nivolumab and they received more doses of nivolumab, however in Cox analysis we did not find patients with irAE to experience progression later than patients without them.
Conclusions: Nivolumab therapy is associated with an increased risk of endocrine adverse effects, particularly thyroid dysfunction. Endocrine adverse effects can be successfully treated pharmacologically and usually do not require discontinuation of immunotherapy. The relationship between a better cancer prognosis in patients who developed endocrine irAE has not been found.