Immunotherapy-induced hepatitis in metastatic colorectal cancer: a systematic review and meta-analysis

Recent advances in immunotherapy using immune checkpoint inhibitors (ICIs) for various cancers have also highlighted a rise in immune-related adverse events, including hepatitis, potentially leading to the discontinuation of treatment. This study aimed to evaluate the prevalence of hepatitis in metastatic colorectal cancer (mCRC) patients undergoing different ICI therapies. An extensive search of PubMed, PubMed Central, and Google Scholar up to November 2023 identified relevant studies. After excluding non-English articles, case reports, reviews, ongoing trials, and studies combining other therapies, five studies qualified for inclusion. Data extraction and statistical analyses were performed using Excel and Comprehensive Meta-Analysis software, respectively. Results from a subgroup analysis indicated that the incidence of hepatitis was comparable among patients treated with PD-1 monotherapy, PDL-1 monotherapy, and combination PD-1 and CTLA-4 therapy, with rates of 2.6%, 2.2%, and 1.7% for any grade and 2.1%, 2.2%, and 1.7% for grade ≥3 hepatitis, respectively. Naive-treated mCRC patients exhibited higher hepatitis rates than those previously treated (3.2% vs 1.6% and 2.6% vs 1.6% for any grade and grade ≥3, respectively). This study underscores the similar risk of hepatitis across different ICI therapies, with an increased incidence in naive-treated mCRC patients.