Incidence and prognostic significance of vascular invasion in 529 gastric-cancer patients.

The prognostic significance of blood-vessel invasion (BVI) and lymphatic-vessel invasion (LVI) was evaluated in a retrospective series of 529 gastric-cancer patients who underwent potentially curative surgery. Evidence for BVI was found in 127 patients (24.0%), while LVI was demonstrated in 245 patients (46.3%). The incidence of both BVI and LVI run parallel to increasing tumor size and tumor stage as well as to decreasing grade of tumor differentiation. The incidence of BVI and LVI was higher in lymph-node-positive patients than in lymph-node-negative patients. The 5-year-survival rate was significantly lower (p less than 0.0001) in patients with BVI or LVI (14.9% and 22.2% respectively) than in patients without BVI or LVI (54.7% and 64.1% respectively). Both BVI and LVI were shown to be prognostic factors independent of tumor stage, grade of differentiation or lymph-node involvement. In a multivariate Cox regression analysis, the gain of prognostic information provided by the evidence of BVI and LVI was shown to exceed the information obtained by the combination of tumor stage, grade of differentiation and lymph-node involvement. A careful search for vascular invasion in gastric cancer may therefore provide additional useful information for identifying patients who are at high risk and who may be candidates for adjuvant therapy in future clinical trials.