The node ratio as prognostic factor after curative resection for gastric cancer.

INTRODUCTION

The depth of the tumor invasion and nodal involvement are the two main prognostic factors in gastric cancer. Staging systems differ among countries and new tools are needed to interpret and compare results and to reduce stage migration. The node ratio (NR) has been proposed as a new prognostic factor.

MATERIALS AND METHODS

We retrospectively reviewed 282 patients who underwent curative resection for gastric cancer at Parma University Hospital between 2000 and 2007. TNM stage, NR, overall survival, survival according to nodal status, and survival according to the total number of nodes retrieved were calculated.

RESULTS

At univariate analysis, the TNM stage, number of metastatic nodes, NR, and depth of tumor invasion, but not the number of nodes retrieved, were significant prognosis factors. Patients with more than 15 nodes retrieved in the specimen survived significantly longer (p < 0.04). This was confirmed for all N or NR classes within N groups. There was a correlation between the number of nodes retrieved and N but not with the NR category. NR was an independent prognostic factor at Cox regression.

CONCLUSION

NR is a reliable and sensitive tool to differentiate patients with similar characteristics, probably more so than the TNM system. NR is not strictly related to the number of nodes retrieved and this may potentially decrease the stage migration phenomenon. More trials are needed to validate this factor.