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

• Capecitabine in mono-regimen
• 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.

Inclusion criteria

• Age 70 years and older;
• Obtaining informed consent to participate in the study;
• Morphologically confirmed diagnosis of colorectal cancer;
• Stage III colorectal cancer;
• Underwent radical surgical intervention for primary colorectal tumor;
• ECOG score of 0 - I;
• Life expectancy of more than 6 months;
• No history of systemic drug therapy for CRC;
• Adequate liver, kidney and bone marrow function;
• Absence of severe uncontrolled concomitant chronic diseases and acute illnesses.

Exclusion criteria

• Having previously received any systemic therapy for CRC;
• Time after surgical treatment of more than 12 weeks;
• Stage I-II and IV disease;
• Confirmed dihydropyrimidine dehydrogenase deficiency in blood by PCR (alteration of alleles c.[190511G > A], c.[1679T >G],[2846A > T], [1129-5923C >G], [c.1236 G>A(HapB3)]);
• Severe uncontrolled comorbid chronic diseases or acute illnesses;
• Presence of a second malignancy (except for previously cured malignancies);
• Any condition that, in the opinion of the physician, would interfere with the study procedures.