Expression of Bacillus in colorectal tissues is associated with improved cetuximab therapy for patients with metastatic colorectal cancer.
Journal
Translational oncology
Journal Volume
63
ISSN
1936-5233
Date Issued
2026-01
Author(s)
Hsu, Hung-Chih
Chung, Hsin-Yu
You, Jeng-Fu
Lee, Yun-Shien
Chang, Jeng-Shou
Wang, Chuang-Wei
Abstract
Metastatic colorectal cancer (mCRC) remains the second leading cause of cancer-related deaths worldwide. Previous studies have shown that somatic mutations and gut microbiota contribute to mCRC progression. However, whether microbiota profiles in colorectal tissues are related to mCRC prognosis and correlate with patients' somatic mutations remains unclear.
We aimed to characterize microbiota expression profiles in formalin-fixed paraffin-embedded (FFPE) colorectal cancer tissues of patients with mCRC to analyze their prognostic role.
FFPE cancer tissues from 65 patients with mCRC were divided into two groups based on overall survival (OS > 4years, OS < 4 years). These groups were analyzed for microbiota expression profiles, somatic mutations, and treatment outcomes.
Higher relative expression of Bacillus and Coprococcus in metastatic colorectal tumor tissues were associated with longer overall survival (hazard ratio [HR] = 0.5; p = 0.008 and 0.013, respectively), while higher Streptococcus expression had a shorter overall survival (HR = 2.0; p = 0.011). Patients with PTPRT/D and without KMT2D mutations had higher Bacillus expression in colorectal tumor tissues (all p < 0.05). Importantly, patients with higher Bacillus expression who received cetuximab (an epidermal growth factor receptor [EGFR] inhibitor) therapy had longer overall survival (median 34.1 months vs 19.4 months; HR = 0.5; p = 0.029) and progression-free survival (median 12.6 months vs 6.2 months; HR = 0.5, p = 0.0019) compared with those with lower relative expression.
Our study suggests that Bacillus expression in colorectal tissues is associated with improved outcomes in patients with mCRC receiving cetuximab therapy.
Subjects
Bacillus
Metastatic colorectal cancer
Microbiota profiles
Somatic mutations
Type
journal article