Glucose Homeostasis and Shared Genetic Factors in Colorectal Cancer

Colorectal cancer (CRC) and diabetes mellitus (DM) are major public health challenges worldwide. Epidemiological studies have demonstrated a bidirectional association between these two diseases, suggesting the existence of shared biological mechanisms involving glucose regulation, inflammation, immunity, and genetic susceptibility. However, the genetic and molecular pathways linking CRC and abnormal glucose homeostasis remain incompletely understood.

Recent genomic studies have identified several candidate pleiotropic genes that may influence both glycemic traits and CRC risk. Among these candidates, SMAD7 has emerged as a potential shared genetic factor involved in glucose homeostasis, inflammatory signaling, immune regulation, and colorectal tumorigenesis. SMAD7 participates in the TGF-β and NF-κB signaling pathways and may influence interactions between metabolic dysregulation, chronic inflammation, and cancer progression.

The present study is designed to investigate the genetic, molecular, metabolic, and immunological relationships between CRC and glucose homeostasis abnormalities. Large-scale genomic resources and clinical data will be integrated to identify and validate shared genetic variants associated with both conditions. In addition, a prospective observational cohort will be established to evaluate longitudinal changes in glucose metabolism, inflammatory biomarkers, immune cell profiles, and gene expression patterns in patients with CRC.

Particular emphasis will be placed on the characterization of systemic and tumor-associated immune responses, including cytotoxic T lymphocytes and regulatory T cells, and their relationships with glucose homeostasis and candidate genetic variants. Blood samples and available colorectal tissue specimens will be analyzed using molecular, genomic, and immunologic approaches to explore potential mechanisms linking metabolic abnormalities and colorectal cancer progression.

By integrating genetic discovery with clinical and biological investigations, this study aims to improve understanding of the shared pathways between CRC and diabetes-related traits, identify biomarkers associated with disease progression, and provide a foundation for future precision medicine strategies in colorectal cancer.

Inclusion criteria

• Age 20 to 85 years
• Histologically confirmed colorectal cancer
• Newly diagnosed colorectal cancer at the time of enrollment
• No prior diagnosis of diabetes mellitus
• Ability to provide written informed consent

Exclusion criteria

• Age younger than 20 years or older than 85 years
• Pre-existing diagnosis of diabetes mellitus
• Severe obesity (body mass index ≥35 kg/m²)
• Pregnancy
• Inability or unwillingness to provide informed consent