Vitamin D supplementation improves the prognosis of patients with colorectal cancer liver metastases

Colorectal cancer liver metastasis (CRCLM) is one of the deadliest cancers. CRCLM tumours have two distinct histopathological growth patterns (HGPs) including desmoplastic HGP (DHGP) and replacement HGP (RHGP). The DHGP tumours are angiogenic, while their RHGP counterparts are vessel co-opting. The patients with DHGP tumours have a better response to anti-angiogenic agents and chemotherapy, as well as the prognosis. To determine the influence of vitamin D supplementation in CRCLM, we analyzed the HGPs and the 5-year OS of CRCLM patients (n=106). Interestingly, we found an inverse correlation between vitamin D supplementation and the presence of RHGP tumours in CRCLM patients. Additionally, the 5-year OS of the patients that administered vitamin D was significantly higher. The cancer cells in RHGP lesions are characterized by direct contact with the hepatocytes, and this phenomenon enhances the motility of the cancer cells and facilitates their infiltration through liver parenchyma to co-opt the pre-existing vessels. Significantly, our in vitro data demonstrated the downregulation of motility markers in the co-cultured cancer cells with hepatocytes upon exposure to vitamin D. Altogether, this study highlights the role of vitamin D in CRCLM and provides a rationale to investigate the contribution of vitamin D supplementation to the prognosis of CRCLM patients.