Prognostic significance of macroscopic serosal invasion in advanced gastric cancer

Although histologic invasion of the gastric serosa is associated with poor prognosis in patients with gastric cancer, the prognostic significance of macroscopic invasion of the serosa is not clear. The aim of this study was to clarify the clinical significance of macroscopic serosal invasion in advanced gastric cancer.

Clinicopathologic data from 257 patients who underwent curative gastrectomy for advanced gastric cancer was analyzed to evaluate the prognostic significance of macroscopic serosal invasion. On the basis of macroscopic findings, tumors were classified as SO, negative serosal invasion; S1, positive serosal invasion; or S2, invasion extending to the adjacent organ. We also examined the relation between the extent of macroscopic serosal invasion (SO, S1, S2) and volumetric shape of cancerous invasion (funnel, column, and mountain types).

In comparison with SO tumors, S1 and S2 tumors were significantly more likely to be more than 5cm in diameter and show histologically serosal invasion. Volumetric analysis showed that S1 and S2 tumors were more frequently column- or mountain-shaped than were SO tumors. The 5-year survival rate differed significantly between patients with SO, S1, and S2 tumors (88% us. 65% vs. 18%, P<0.01). Multivariate analysis indicated that macroscopic serosal invasion was an independent prognostic factor.

Macroscopic serosal invasion is associated with extensive cancerous invasion of the deep gastric wall. The presence of macroscopic serosal invasion indicates advanced tumor progression and poor prognosis for patients with advanced gastric cancer. Clinically, knowledge of the extent of macroscopic serosal invasion is helpful in planning adjuvant chemotherapy.