Role of intraoperative assessment of lymph node metastasis and serosal invasion in patients with gastric cancer.

The clinical diagnoses of nodal status (N) and tumor invasion (T) were performed intraoperatively during 1499 consecutive operations for gastric carcinoma and compared with subsequent pathologic diagnoses. An accurate macroscopic diagnosis of N stage was difficult; overall accuracy was only 56.6%. Intraoperative assessment of T stage (particularly of serosal invasion) was correct for 93.2% of early stages of the disease with invasion confined to the mucosa or submucosa (pT1) when the pathologist assessed the T stage in the resected specimen, for 95.6% of advanced tumors invading the serosa (pT3), but for tumors of an intermediate stage with invasion involving the muscularis propria or the subserosa (pT2) in only 41.9% of cases. Macroscopic overestimation occurred in 58.1% of cases with pT2 tumors, which were characterized by carcinomas in the upper third of the stomach, tumors larger than 5 cm, carcinomas of the ulcerating type, differentiated adenocarcinomas, tumors invading the subserosa, and those accompanied by lymph node metastasis or liver metastasis. The overestimated group had a significantly poorer prognosis than the correctly assessed cases (P < 0.05). Since multivariate logistic regression analysis showed that the significant risk factor related to the inaccurate intraoperative assessment of T stage was tumor size, the error in diagnosis may correlate with a greater degree of tumor spread. Surgeons should decide their therapeutic approach at the time of surgery on the basis of their intraoperative assessment of tumor spread. We recommend extensive surgery followed by adequate chemotherapy when serosal invasion is suspected at surgery.