A portion of stage I/II colon cancers (10-20%) exhibit an adverse clinical course. The administration of adjuvant chemotherapy is recommended only in certain high-risk situations. However, these risk factors recently failed to predict benefit from adjuvant therapy. We composed a new morphology-based risk score that includes pT1/2 versus 3/4 stage, vascular or lymphovascular invasion, invasion type according to Jass, tumor budding and paucity (less than two) of lymph nodes larger than 5 mm. The occurrence of each of these factors accounts for one point in the score (Range 0-5). This score was evaluated in a retrospective study that included 301 cases. The overall survival differed significantly between the three groups with median survival times of 103, 90, and 48 months, respectively. Multivariable analysis revealed morphology-based risk-high risk and low risk-as the sole independent factors for the prediction of death. Morphology-based risk scoring was superior to microsatellite status and NCCN risk stratification. This method identifies a group of patients that comprises 18% of the stage II cases with an adverse clinical course. Further studies are necessary to confirm its prognostic value and the possible therapeutic consequences.
Keywords: Colon Cancer; Histomorphology; Prognosis; Risk Stratification; Stage I/II.
© 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.