Immune-related adverse events as predictors of response in cancer patients undergoing immunotherapy.

OBJECTIVE

To determine the incidence of immune-mediated adverse reactions with and without radiologic manifestations and to correlate them with the response to immunotherapy.

MATERIAL AND

METHODS

We retrospectively included 79 patients with stage IV lung carcinomas (n=24), renal carcinomas (n=11), or melanoma (n=44) treated with immunotherapy. We evaluated the occurrence of immune-mediated adverse reactions, their radiologic manifestations, and the response pattern according to the immune-related response criteria (irRC). We correlated the presence of immune-mediated adverse reactions with the response pattern.

RESULTS

Immune-mediated adverse reactions occurred in 27.8%, being most common in patients with melanoma (40.9%). In 59.1% of patients with adverse reactions, there were radiologic manifestations such as pneumonitis, colitis, hypophysitis, thyroiditis, or myocarditis. Pneumonitis was the most common radiologic manifestation of immune-mediated adverse reactions, even in asymptomatic patients. The rate of response to immunotherapy was higher among patients who developed immune-mediated adverse reactions than in those who did not (68.2% vs. 38.6%, respectively, χ2 5.58; p=0.018). The rate of favorable responses was higher in patients with radiologic manifestations of immune-mediated adverse reactions than in those without radiologic manifestations (84.6% vs. 44.4%, respectively; p=0.023).

CONCLUSIONS

The presence of immune-mediated adverse reactions is associated with a better response to immunotherapy. The association with a favorable response is even stronger in patients with radiologic manifestations of the immune-mediated adverse reactions.