Prognostic significance of depth of invasion, vascular invasion and numbers of lymph node retrievals in combination for patients with stage II colorectal cancer undergoing radical resection

Background and Objectives: To determine which aspects of tumor histology influenced the postoperative relapse and overall survival rates after radical resection of UICC stage II colorectal cancer (CRC). Methods: Data were collected on 259 patients with stage II CRC who underwent radical resection in Kaohsiung Medical University Hospital between January 2002 and December 2005. Results: A univariate analysis identified that the depth of invasion, the presence of vascular invasion, the presence of perineural invasion, and the number of examined lymph nodes were significant prognostic factors for postoperative relapse. A combination of depth, vascular invasion, and numbers of lymph node retrieval as predictors of postoperative relapse showed that the more predictors that are involved, the higher chance that postoperative relapse would occur. Furthermore, T4 depth of tumor invasion, the presence of vascular invasion, and the number of examined lymph nodes <12 were considerably correlated to the poorer overall survival rates by survival analyses. Conclusions: This study has revealed that the depth of invasion, the presence of vascular invasion, and number of examined lymph nodes, may prominently affect the prognosis of stage II CRC patients after radical resection. The increasing risk of postoperative relapse is proportionate to numbers of these three parameters.