Tumor cell dissociation score highly correlates with lymph node metastasis in superficial esophageal carcinoma

It is still not clear which parameters are important for predicting the metastatic potential of superficial esophageal squamous cell carcinoma (SESCC). The purpose of the present paper was thus to investigate tumor cell dissociation (TCD) in SESCC as a predictive factor of lymph node metastasis.

Thirty-three SESCC were classified into four groups based on the depth of tumor invasion. Carcinomas not invading as far as the muscularis mucosa were classified as group A; carcinomas invading to the muscularis mucosa or less than one-third of the upper submucosa were classified as group B; those invading to the middle layer of the submucosa were classified as group C; and those invading one-third of the lower submucosa were classified as group D. The TCD score was calculated by dividing the length of the TCD region by the maximal longitudinal length of the area of invasion into or beyond the lamina propria, and multiplying by 100. E-cadherin expression of the carcinomas was investigated in the TCD area and the successive area of mucosal invasive carcinoma (SAM).

The incidence of lymph node metastasis was 0% in group A, 10% in group B, 36.4% in group C and 57.1% in group D. The mean TCD scores (+/-SEM) of SESCC with lymph node metastasis were higher than that without (85.3 +/- 5.7, 16.3 +/- 3.9, respectively; P < 0.001). In group C, the TCD score of cases with lymph node metastases was higher than in those without lymph node metastasis (P < 0.001). E-cadherin expression was significantly reduced in the area of TCD compared with the SAM located over the TCD area (P < 0.001).

The TCD score is an important predictive marker for lymph node metastasis in SESCC. Clinical evaluation of TCD scores in endoscopic mucosal resection (EMR) specimens would enable accurate prediction of lymph node metastasis and extend the indication of EMR treatment for SESCC.