Perineural invasion as a predictor of recurrence of gastric cancer

Perineural invasion (PNI) plays a role in local invasion of pancreatic, biliary tract, and large intestine cancers and greatly affects the prognosis. Although PNI of gastric cancer has been reported rarely, the authors previously reported the usefulness of immunohistochemical staining with laminin in evaluating PNI.

PNI was studied histochemically in 283 patients with gastric tumors of T2 or greater depth of invasion resected between 1982 and 1989. The relationships between PNI and histopathologic findings, type of recurrence, and prognosis also were studied.

Of the 216 patients who underwent resection for cure, 103 experienced tumor recurrence. Recurrence correlated significantly with lymphatic vessel invasion, lymph node metastasis, and PNI. Peritoneal recurrence was found in 65 (63.1%) of the 103 patients with tumor recurrence and correlated most significantly with PNI in T2 tumors. The 5-year survival rate was 71.3% for patients with PNI-negative tumors, significantly higher than the 5-year survival rate (23.7%) for patients with PNI-positive tumors. A multivariate analysis using a Cox regression model of the relationship between histopathologic findings and prognosis demonstrated that the presence of PNI had the greatest influence on prognosis.

The evaluation of PNI is useful in determining the prognosis of gastric cancer of T2 class with no serosal invasion.