Use of immune checkpoint inhibitors in patients with solid tumors and pre-existing autoimmune or inflammatory...

Immune checkpoint inhibitors (ICIs) are a cornerstone in cancer treatment but they can induce immune-related adverse events (irAEs). Furthermore, patients with pre-existing autoimmune and/or inflammatory disease (AID) have been excluded from clinical trials. The objective of this study is to evaluate the efficacy and safety of ICIs in patients with cancer and AID.

This is an observational, retrospective study carried out at the Medical Oncology Department of Hospital Universitario Puerta de Hierro, Majadahonda, Madrid between January 2016 and December 2018.

A total of 202 cancer patients treated with ICIs were included, 15 (7, 4%) of them had pre-existing autoimmune diseases. The most frequent pre-existing AID were thyroid diseases (33.3%): autoimmune hypothyroidism, Graves-Basedow disease and Hashimoto's thyroiditis. Three patients had psoriasis, two antinuclear antiboides + polyarthritis, one rheumatoid arthritis, another latent autoimmune diabetes in adults, another systemic lupus erythematosus and the last one, a polymyalgia rheumatica. In this series, the majority of patients (73.33%) did not experience any flare up of their autoimmune disease. In patients who had AID flare up, this was treated with corticosteroids. The most frequent cause of immunotherapy discontinuation was tumor progression (40%). A total of 20% of patients had to discontinue immunotherapy due to toxicity.

In our series, AID flare ups or irAEs in patients with pre-existing AID who receive immunotherapy are not very common and can often be controlled without interrupting treatment. Prospective studies are needed to establish the incidence of irAEs in patients with pre-existing autoimmune conditions, evaluate risk-benefit and elaborate management clinical guidelines in this population.