Study to Evaluate the Use of Capecitabine in Monotherapy and in Combination With Oxaliplatin in Elderly Patients as Adjuvant Chemotherapy for Locally Advanced Colorectal Cancer.

The study is a single-center, open-label, randomized Phase II study. The study will be divided into a screening phase (4 weeks prior to inclusion in the study), a treatment phase (up to 6 months) and a long-term follow-up phase (up to 28 days from the end of treatment - follow-up to assess the safety of therapy, up to 3 years from the end of treatment to assess survival and follow-up). During the screening phase, patients with MR CRC will undergo examinations to fulfill the inclusion and exclusion criteria for the study. Next, elderly patients meeting these criteria-who have locally advanced colorectal cancer-will be randomized in a ratio of approximately 1:1 into 2 groups. The study is planned to include 160 patients, 80 in each group, for a total of 160 patients. Patient groups 1. Capecitabine in mono-regimen 2. PCT according to XELOX regimen Stratification factors - gender m/f, age \<75 /\>75, presence of postoperative complications yes/no. The patients will be treated until the progression is detected or the maximum effect of therapy is achieved (the longest duration of treatment is 8 cycles). At the end of the treatment period, all patients will enter the observation phase.