Population-based matched case-control study of diabetes and colorectal cancer risk and survival according to tumor immunity status

Type 2 diabetes (T2D) has been associated with an increased risk of colorectal cancer (CRC) and poorer survival outcomes; however, the role of tumor immune status in influencing these relationships is not clear. A population-based matched case-control study in Germany with prospective long-term follow-up of CRC cases (median 9.5 years) found that T2D disproportionally affects CRC risk and survival in tumors with low immune infiltration, suggesting a continuum of T2D’s impact from tumorigenesis to prognosis, through systemic and tumor-specific immune modulation.