Traditional Chinese medicine (TCM) for prevention and management of anti-EGFR monoclonal antibody (mAb)–induced cutaneous adverse reactions in patients with metastatic colorectal cancer (mCRC): A retrospective analysis.

e15584 Background: Anti-EGFR mAb have significantly improved clinical outcomes in mCRC by inhibiting the EGFR signaling pathway. However, these agents can also disrupt EGFR function in normal tissues, causing acneiform eruptions. Shengma Biejia Decoction primarily clears heat and toxins, cools the blood, and disperses blood stasis, mainly for patterns of heat toxin invading the blood and combined stasis and heat. This offers a novel approach for preventing and treating these adverse reactions. Methods: This retrospective analysis included mCRC patients who received cetuximab at Longhua Hospital, Shanghai University of Traditional Chinese Medicine, from 2022 to 2025. A total of 41 patients were screened; after excluding those with incomplete records or who received only one cycle due to poor tolerance and switching therapies, 35 patients were enrolled. Based on clinical regimens, patients were divided into a TCM arm (n = 25) and a non-TCM arm (n = 10). Patients in the TCM arm received oral Shengma Biejia Decoction combined with cetuximab throughout treatment. One dose was decocted daily to 300 mL and taken warm in two divided doses, morning and evening. Patients in the non-TCM arm received conventional symptomatic treatment. The primary endpoint was the incidence of any grade skin reactions (per CTCAE 5.0) in both groups, compared using Fisher’s exact test. Results: At baseline, 28 patients (80.0%) were male and 34 (97.1%) had stage IV disease. Liver, lung, and peritoneal metastases were present in 20 (57.1%), 6 (17.1%), and 9 (25.7%) patients, respectively. Cetuximab was used as conversion therapy in 3 (8.6%), first-line in 23 (65.7%), and second-line or later in 11 (31.4%) patients. In the entire cohort, the incidence of any grade cutaneous adverse reactions was 31.4%, and severe reactions 8.6%. there was a significant difference in any grade skin reactions between the TCM arm and non-TCM arm (20.0% vs. 60.0%, p = 0.041) . Among 20 elderly patients (≥65 years), 14 and 6 patients were allocated to the TCM arm and non-TCM arm, the incidence of any grade skin reactions was 21.4% vs. 66.7%, respectively. These findings suggest the TCM formula may help reduce skin reactions in elderly patients undergoing antitumor therapy. Previous studies report anti-EGFR mAb–related any grade skin reactions rates up to 81.4%, while the overall incidence in our study was much lower. Conclusions: In patients with mCRC receiving cetuximab, concomitant use of Shengma Biejia Decoction–based TCM formula can significantly lessen skin reactions. At the same time, this regimen shows a favorable safety profile, and contributes to better overall quality of life. These findings provide TCM-based evidence to guide the clinical prevention and management of cetuximab-related skin reactions.