Colon cancer represents one of the most common and lethal forms of malignancy in the human population, accounting for approximately 10% of global cancer diagnoses and >570 000 annual deaths worldwide.

Among patients diagnosed with colon cancer, approximately one-third (35%) are diagnosed with a tumor that is locally advanced (i.e., infiltrating beyond the full thickness of the muscular layer of the intestinal wall) but not yet overtly metastatic, a condition defined as stage II by the American Joint Committee on Cancer staging manual.
 Most patients with stage II colon cancer are cured by surgical resection of the primary tumor, but a substantial percentage (10%-15%) are poised to relapse and eventually die of the disease.

A common strategy implemented in medical oncology to improve the survival of patients with a locally advanced malignancy is to treat them with adjuvant chemotherapy (i.e., chemotherapy administered after surgical resection of all detectable tumor tissue) to prevent relapse from undetectable cancer cells. Adjuvant chemotherapy, however, can cause toxicity and is best reserved for patients who are both at high risk of relapse and affected by chemosensitive tumors. In the specific case of stage II colon cancer, several prognostic factors have been identified as capable of stratifying patients into “high-risk” versus “low-risk” categories with regard to the likelihood of relapse, but none have proven useful to identify patients who would indisputably benefit from adjuvant chemotherapy, leaving clinicians uncertain with regard to the best treatment strategy.