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The directionality of lymphatic spreading as a prognostic factor in gastric cancer: uni- or multidirectional lymphatic metastases.

BACKGROUND/AIMS
The most critical problem of the numerical lymph node staging system is difficulty in evaluating preoperative staging. We investigated the directionality of metastatic lymph nodes as an alternative prognostic indicator of gastric cancer.


METHODOLOGY
One hundred and seventy two patients who had undergone curative gastrectomy were examined. We divided the stations of lymph nodes into three zones according to the anatomical site. Then patients were classified into two groups according to the number of positive zones, unidirectional or multidirectional lymphatic spreading.


RESULTS
Seventy-five patients showed unidirectional lymphatic spreading, whereas 97 patients showed multidirectional. Logistic regression analysis showed that directionality correlated with the number of metastatic nodes. Directionality was found to be a significant prognostic factor on univariate analysis, but not on multivariate analysis.


CONCLUSIONS
The directionality could be a surrogate marker of total number of metastatic lymph nodes as a prognostic factor in patients with gastric cancer.