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.

Inclusion Criteria:

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

Exclusion Criteria:

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