The clinical utility of the combination of T stage and venous invasion to predict survival in patients undergoing surgery for colorectal cancer.

OBJECTIVE

To examine the clinical utility of improved detection of venous invasion (VI) in patients undergoing potentially curative resection of colorectal cancer.

BACKGROUND

VI is a feature of colorectal cancer (CRC) progression. Elastica staining can be used to improve detection of VI and correspondingly its prediction of patient survival.

METHODS

A single-center, observational study of pathology variables, including detection of VI by staining for elastica, using 631 stage I to III CRC specimens, collected from 1997 to 2009 (176 analyzed retrospectively and 455 analyzed prospectively), was performed.

RESULTS

VI was detected in 56% of patients with CRC. Over a median follow-up period of 73 months, 238 patients died (134 from cancer). On multivariate analysis, VI by elastica staining was associated with a shorter survival duration, independent of other pathology features, in all cases [hazard ratio (HR) = 3.94, 95% confidence interval (CI): 2.33-6.65, P < 0.001] and in node-negative cases (HR = 3.55, 95% CI: 1.81-6.97; P < 0.001). In the absence of elastica-detected VI, with the exception of T stage, no other pathology features were associated with survival time. Therefore, the combination of T stage and VI (TVI) on survival was examined. Five-year cancer mortality could be stratified between 100% and 54% for patients with node-negative tumors and between 100% and 33% for patients with node-positive tumors. In all cases, the TVI had similar predictive value as that of T stage and node status (TNM). In node-negative disease, TVI had superior predictive value.

CONCLUSIONS

The results of the present study have prompted the development of a novel tumor staging system based on TVI. The TVI has clinical utility, especially in node-negative disease, in predicting outcome following curative resection for CRC.