Colon cancer study aims to improve treatment for older patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Subjects are given explanations about the study objectives and methods, and will express their consent by signing a written agreement to use their personal information. 2. Male and female adult subjects who are ≥ 19 years old. 3. Subjects are confirmed to have primary colon cancer through histological diagnosis and are at \*high-risk stage II (T3/4, N0M0) or stage III (any T, N1/2, M0). * High-risk stage II is determined when one or more of the following are applicable. 1. Cancer is at T4 stage (stage IIB,IIC); 2. Cancer cell differentiation grade is 3 or 4 (poor histologic grade); 3. Cancer cells are present in lymphatic or blood vessels around the tumor (peritumoral lymphovascular involvement); 4. Ileus was present during surgery (bowel obstruction at presentation); 5. Cancer is at T3 stage with localized perforation or there are indeterminate cancer cells residual on the incisal surface. (T3 lesions with localized perforation or close, indeterminate, or positive margins); or, 6. Cancer cells invaded into the area around the ganglion (perineural invasion). 4. Subjects are decided to require adjuvant chemotherapy including oxaliplatin and/or capecitabine after curative resection (E.g.: FOLFOX, CapeOx or Capecitabine and modified therapies). 5. Subjects' performance status score (ECOG PS) is 2 or lower (0, 1, 2). Exclusion Criteria: 1. Subjects are diagnosed with other primary cancers that can influence the treatment or prognosis of primary rectal and colon cancers. 2. Subjects are diagnosed with relapsed or secondary colon cancer. 3. Subjects with Stage 0/1 (Tis/1/2, N0M0) or Stage IV (any T, any N, M1) colon cancer. 4. Subjects who are currently on adjuvant chemotherapy after curative resection. 5. Subjects who are receiving palliative chemotherapy. 6. Pregnant and breast-feeding subjects. 7. Subjects who are currently participating in other clinical trials (clinical trials for drugs or medical devices) or are planning to participate in other clinical trials during the duration of this study. However, subjects participating in a noninterventional observational study or a registry study can participate in this study. 8. Other subjects who are not suitable for study participation upon the investigator's decision.