Gastric carcinoma confined to the muscularis propria: how can we detect, evaluate, and cure intermediate-stage carcinoma of the stomach?

OBJECTIVE

The most important surgical strategy for advanced gastric cancer is its detection at the curative stage. The aim of this study was to characterize the curable intermediate-stage gastric carcinomas.

METHODS

Of 1120 consecutive patients who underwent gastric resection for primary gastric cancer from 1979 through 1996, 94 patients were histologically diagnosed as having cancer confined to the muscularis propria (mp cancer), analyzed clinicopathologically, and compared with patients with early and serosal cancers.

RESULTS

The operative incidence of mp cancer was around 8% among cases of gastrectomy, and the ratio of mp cancer to advanced cancer began to increase in 1991. Mp cancer was at a statistically intermediate stage, between early and serosal cancers in terms of symptoms, surgical curability (96%), size and histology of the tumor, and the rate of lymph node metastasis (46%). Preoperative assessments of tumor depth were unclear using radiology and endoscopy; however, 35% of 31 cases studied were diagnosed precisely by endoscopic ultrasonography (EUS). Accuracy of lymph node metastasis diagnosis was the same (65%) by preoperative EUS and by surgeon; however, sensitivity of the surgeon's assessment was higher (69% vs 38%) and specificity of EUS was higher (83% vs 39%). The 5-yr survival rate was 85%, which was significantly better than that of serosal cancer and similar to that of early cancer. Patient outcome was not affected by lymph node metastasis or macroscopic type of tumor.

CONCLUSIONS

Mp cancer should be considered an intermediate-stage cancer. Surgery with level 2 lymph node dissection should provide a cure rate similar to that for early cancer.