Real-world Efficacy and Safety of Neoadjuvant Dostarlimab in Patients With dMMR/MSI-H Locally Advanced Rectal Cancer

Inclusion Criteria: * Signed informed consent form * Age \> 18 years * Histologically confirmed stage II-III rectal cancer * dMMR/MSI status assessed locally by Immunohistochemistry, next-generation sequencing or PCR For the retrospective part of the study: * At least one dose of neoadjuvant dostarlimab from November 2023 (i.e. within the period of AIFA dostarlimab monitoring registry activation for the indication in rectal cancer, which is reimbursed according to the Italian law 648/1996, GU n.252 as of 27/10/2023) * Eligible deceased or unreachable patients will also be included to avoid selection biases, in respect of the article 110 bis, paragraph 4 of the Italian Privacy Code (a Data Protection Impact Assessment will be produced and published on the Sponsor website before study initiation, and patients explicitly unwilling before death will be not included). For the prospective part of the study: \- Inclusion in the AIFA dostarlimab monitoring registry for the indication in rectal cancer, to receive dostarlimab according to the Italian law 648/1996, GU n.252 as of 27/10/2023 Exclusion Criteria: * \- Distant metastasis * Major cognitive dysfunction or psychiatric disorders * Any previous systemic or local treatment for rectal cancer * Dostarlimab received within an interventional clinical trial