Abstract 1066P
Background
Immunotherapy has demonstrated durable responses and prolonged survival in metastatic lung cancer. Thyroid dysfunction is an immune related adverse event, with reported incidence rates ranging from 2% to 20% of the cases. The occurrence of this type of adverse event is widely described with immunotherapy, but its predictive role is still not entirely clear [1,2,3] We will present the first serie, that we are aware of, in a Latin American population.
Methods
Objective: Describe the incidence of thyroid dysfunction (hypothyroidism or hyperthyroidism) and its relationship with progression-free survival (PFS) and overall survival (OS) in metastatic lung cancer patient. Methods: Retrospective observational cohort study. Patients with metastatic lung cancer who received immunotherapy at the Hospital Italiano de Buenos Aires from Sep/2013 to March/2019 were included. Clinical characteristics of the patients, presence of altered TSH before and during immunotherapy treatment were evaluated. PFS and OS were analyzed with Kaplan Meier curves and comparison between groups was performed with LogRank test. Outcomes during treatment with immunotherapy were characterized as: no thyroid dysfunction: normal TSH levels throughout or thyroid dysfunction: at least one abnormal TSH levels.
Results
99 patient were incluied, median age 65 years. The most common histology was adenocarcinoma(87%). No significant differences were found between the hypothyroidism populations and not hypothyroidism populations, regarding PdL1, performance status, histology, the line of treatment, or brain or liver involvement. 38.5 % (32/83) developed thyroid dysfunction (hypothyroidism 23% (19/83)) Development of hypothyroidism was associated with an improvement in OS (32.7 months vs. 16.2 months, Log-Rank test p 0.0088), The 1-year OS was 100% in patients who developed hypothyroidism vs. 50% in patients without such toxicity. The hypothyroidism was not associated with PFS. In multivariate analysis, development of hypothyroidism was an independent prognostic factor for OS (p 0.045).
Conclusions
Prevalence of thyroid dysfunctions in our population is higher than the reported in the literature. Association between hypothyroidism and increased OS is evident.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Hospital Italiano de Buenos Aires.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.