Adjuvant treatment of colon cancer with microsatellite instability - the state of the art.

Adjuvant chemotherapy with fluoropyrimidine (FP) plus oxaliplatin in stage III resected colorecatal cancer (RCRC) resulted in a 30% relative reduction of disease recurrence risk and mortality. The presence of altered mismatch repair genes identify tumors with microsatellite instability (MSI) that have a better prognosis than stable tumors, but data about adjuvant chemotherapy benefit in this subgroup are compelling. We investigate the role of adjuvant therapy in resected MSI RCRC. The standard treatment is the association of FP plus oxaliplatin, while it can avoided in low risk stage II, thanks to its good prognosis. We propose a practice strategy to approach MSI RCRC in line with the current knowledge. In consideration of the dramatic results in chemorefractory MSI metastatic CRC, there are assumptions that immunotherapy can become a potential alternative to classical systemic therapies also in the adjuvant setting. We await the results of ongoing studies to draw further conclusions."