Prognostic study of gastric cancer without serosal invasion: reevaluation of the definition of early gastric cancer.

BACKGROUND

Early gastric cancer, a term defined by Japanese researchers in the 1960s, is equivalent to pT1 tumor stage regardless of nodal status. Recently, there were suggestions to exclude node-positive pT1 gastric cancer from this entity and to consider node-negative pT2 gastric cancer as early gastric cancer.

STUDY DESIGN

A survival analysis was conducted of 294 patients who underwent resection for gastric cancers confined within the gastric wall (pT1, n = 164; pT2, n = 130) between 1986 and 1992.

RESULTS

The cumulative 5-year survival rate was 93.5% for pT1 patients and 67.9% for pT2 patients, with an overall survival of 82.5%. There was a significant difference in the 5-year survival rate between node-positive and node-negative pT1 patients (72.8% versus 95.6%; p = 0.0095). The 5-year survival rate of node-negative pT2 patients (80.4%) was significantly worse than that of node-negative pT1 patients (p = 0.011) but was not significantly better than that of node-positive pT1 patients (p = 0.4). If excellent prognosis is a prerequisite for the definition of early gastric cancer, then node-positive pT1 cancer and node-negative pT2 cancer should not be considered early gastric cancer.

CONCLUSIONS

In the 1990s, now that new imaging techniques such as endoscopic ultrasonography has been introduced, the preoperative staging of gastric cancer can be made more accurately than in the 1960s, when the term "early gastric cancer" was defined. Because the prognosis of early gastric cancers, if subcategorized by nodal status, is not homogeneously excellent, a reevaluation of the definition of early gastric cancer may be necessary.