 - Adjuvant chemotherapy treatment for colon cancer with a 5-fluorouracil- based regimen received with an intent to provide a complete course of treatment. While one current standard is 24 weeks of treatment, patients who are pre-planned to receive a shorter duration of chemotherapy, including as part of a research study will also be permitted. The actual treatment received may be less than 24 weeks; participants must have received a minimum of one treatment cycle. 