Relationship between extent of tumor resection and prognosis: an evaluation in 533 cases of gastric cancer

Objective: To evaluate prognosis of patients with stomach cancer based on the extent of tumor resection.

Methods: Five hundred and thirty-three cases of gastric cancer resected from 1980 through 1990 were divided into 3 categories A, B, and C, in the order of decreasing completeness of tumor resection as set forth in the 12th edition of "Rules for Gastric Cancer in Japan".

Results: There were 157 cases in category A, 209 cases in category B and 167 cases in category C. Their survival rate was 80.9%, 34.9%, and 9%, respectively. In category A and B, the depth of tumor invasion and lymph node metastasis were the major factors affecting survival rate. In the presence of lymph node metastasis, prognosis was dependent on which station (D1-D3) of lymph nodes dissected. In category B, if dissection covered D3 but metastasis was limited to I or II, the 5-year survival rate was 48%; if lymph node dissection performed was limited to the same station of lymph nodes where metastasis occurred, the 5-year survival rate dropped to 22.4% (P < 0.05). In case cancer left over at the cutting edge, the completeness of resection might drop from category A or B to C, and the 5-year survival rate correspondingly decreased to 6% and 12.2%, respectively.

Conclusions: In order to ensure completeness of tumor resection, lymph node station dissected should be farther than that with metastasis, and the distance between the tumor and the cutting edge should be long enough to prevent residual tumor left behind.