# A case series and literature review of immune checkpoint inhibitors-associated myocarditis (ICIM) in non-small cell lung cancer

## TL;DR

This study examines five cases of heart inflammation caused by cancer treatments, highlighting the importance of early detection and the challenges in treating it.

## Contribution

The study provides a case series and literature review to guide early identification and treatment of ICIM in NSCLC patients.

## Key findings

- ICIM occurred within 1–3 cycles of ICI treatment in 5 NSCLC patients.
- Glucocorticoid resistance was high (80%), with a 20% mortality rate.
- Tumor responses were maintained after ICI discontinuation in most cases.

## Abstract

Immune Checkpoint Inhibitors-associated Myocarditis (ICIM) is a rare but life-threatening complication when treating Non-Small Cell Lung Cancer (NSCLC) with Immune Checkpoint Inhibitors (ICIs). This study aims to provide a foundation for optimizing the early identification, accurate stratification, and individualized treatment of ICIM.

A retrospective analysis was performed on medical records of 5 NSCLC patients who developed myocarditis during ICI treatment. Data including demographics, medication history, clinical manifestations, lab tests, and imaging exams were collected, with analysis combined with a literature review.

The 5 patients (4 males and 1 female; aged 62–72 years, with varying NSCLC stages) developed myocardial injury within 1–3 cycles of ICI treatment. All had elevated myocardial markers and non-specific symptoms (palpitations, chest tightness, muscle weakness); 3 had abnormal electrocardiograms (ECGs). Diagnoses included 1 definite, 2 probable, and 2 possible ICIM cases. The glucocorticoid resistance rate was 80% (4/5), with only 1 patient responding effectively; mortality was 20% (1/5). No tumor progression was observed after ICI discontinuation [2 Partial Response [PR], 1 Stable Disease [SD], 1 pathological Complete Response [pCR]].

Early identification and intervention are critical for ICIM. The core treatment is ICI discontinuation plus glucocorticoid administration, but the optimal second-line regimen for glucocorticoid-resistant patients requires further investigation.