Tumor-cell dissociation at the invasion front: a new prognostic parameter in gastric cancer patients

Tumor-cell dissociation (TCD) is a well-known feature at the invasion front of malignant tumors, but little attention has so far been paid to its biological significance. Therefore, the aim of the present study was to score the degree of TCD at the invasion front (TCD 0-3) in a retrospective series of 445 gastric cancer patients and to compare its prognostic significance with the parameters T-stage, tumor size, grade of tumor differentiation, lymph-node involvement and vascular invasion. We could show that highly significant differences (p less than 0.0001, log-rank test) existed between the 5-year survival rates of patients with different degrees of TCD (TCD 0: 92.3%; TCD 1: 62.1%; TCD 2: 41.2%. TCD 3:38.5%) and that these differences were independent of T-stage 2, tumor size and grade of tumor differentiation. Univariate Cox regression analysis showed that in intestinal-type carcinomas, T-stage (Chi-square: 45.2) followed by blood vessel and lymphatic vessel invasion (Chi-square: 43.6 and 40.0) had the highest prognostic value, whereas TCD (Chi-square: 31.5) revealed a prognostic value quite similar to that of lymph-node involvement (Chi-square: 35.1). This prognostic relevance was still present in multivariate Cox regression analysis, showing that the determination of TCD provided an increase in prognostic information which significantly (P = 0.026) exceeded the information obtained by the combination of T-stage and lymph-node involvement. Our data suggest that TCD is a new prognostic parameter, especially in those gastric carcinomas in which lymph-node involvement or vascular invasion are not present.