Neuroendocrine-like differentiation in patients with pancreatic carcinoma

BACKGROUND. The accurate estimation of the rate and the clinicopathologic significance of neuroendocrine-like differentiation (NED) in patients with pancreatic carcinoma have not been studied in detail. METHODS. Forty-four patients with pancreatic carcinoma who underwent surgical resection at the Department of Surgery II, Nagoya University Hospital, were included in this study. For immunostaining, antibodies against neural cell adhesion molecule (NCAM), neuron-specific enolase (NSE), synaptophysin, CD57, and chromogranin A (CGA) were used at given dilutions. At least two positive results with antibodies were considered as NED. Statistical analysis was performed by chi-square and Spearman rank correlation tests for group differences. Survival rates were calculated by the Kaplan-Meier method, and statistical significance was examined using the log rank test. Prognostic factors were tested by univariate and multivariate analyses (proportional hazards regression model). P < 0.05 was considered statistically significant. RESULTS. Of 44 patients examined, 20 showed NED. The distribution of patients with positive or negative NED in terms of age, tumor differentiation, tumor size, and the extent of tumor or lymph node metastasis showed no significant difference. The cumulative survival rates of patient groups according to NED status were then calculated, and NED positive patients showed a significantly better survival rate (P < 0.05). Univariate and multivariate analyses of those factors showed that only NED status and TNM stage were significantly related to overall survival. CONCLUSIONS. The current study suggests the significance of NED status in determining the outcome of patients with pancreatic adenocarcinoma, giving solid evidence to encourage further studies on the differentiation and origin of tumor cells in the pancreas. Cancer 2000;89:2230-6. (C) 2000 American Cancer Society.