Total Neoadjuvant Treatment With or Without Tislelizumab for Locally Advanced Rectal Cancer.

This prospective, multi-center, phase II randomized controlled trial will evaluate the actual benefit of adding immunotherapy with tislelizumab to the currently most effective approach against LARC, namely TNT. In this trial, we will harness several elements that may each potentially contribute to an overall high efficacy, at least in local outcomes: nCRT rather than SCRT, full length (8 cycles of mFOLFOX6) of consolidation chemotherapy, CIMT following nCRT (exploiting the upregulation of the immune response induced by the latter) and tislelizumab (with its theoretical advantage over other CPIs). In line with the changing treatment paradigms in LARC, in which high therapeutic efficacy translates into the possibility to avoid TME, the trial will have a novel primary endpoint of long-term unmaintained cCR, i.e. 3 year TME-free survival.