Personalized Medicine in Early Stage Colorectal Cancer: Organ Preservation and Immune Benefit

The overall aim of this study is to determine whether the Immunoscore associated with histopathological features of endoscopically resected stage T1 colorectal tumors is predictive of locoregional lymph node invasion, in order to better select patients eligible for an organ preservation strategy.

The frequency of stage T1 superficial colorectal cancer (CRC) is around 15% and its incidence increases. In France, T1 superficial CCR is mostly treated with endoscopic submucosal dissection (ESD), offering potentially curative, organ-preserving treatment. The presence of pejorative histological criteria (eg. poor differentiation, budding, lymphovascular invasion), detected in about 50% of the tumors, leads to a secondary colectomy or rectal resection with postoperative complications and significant digestive, urological, and sexual functional sequelae. Strikingly, secondary surgical resection is performed in excess in 70 to 80% of the cases, given that no tumor is evidence in the colon and draining lymph nodes. Organ preservation (no secondary surgery) could be offered to a larger number of patients if biomarkers could complete the histological evaluation to better predict metastatic extension to lymph nodes. Our team showed that the type, density, and location of immune cells in CRC strongly correlated with patients' survival at all disease stages. Our team created an "Immunoscore" (IS) assay, based on CD3+ and cytotoxic CD8+ T-cell densities determined by digital pathology in the tumor and its invasive margin. The robustness and prognostic performance of IS was validated in CRC . Sub-analysis of T1 tumors was not possible (only 31 cases) and tumor specimens did not result from endoscopic resection. The objective of the study is to determine whether the Immunoscore associated with histopathological features of endoscopically resected stage T1 colorectal tumors is predictive of locoregional lymph node invasion, in order to better select patients eligible for an organ preservation strategy.