Neuroendocrine-like differentiation in patients with pancreatic carcinoma

BACKGROUND. The accurate estimation of the rate and the clinicopathologic s ignificance of neuroendocrine-like differentiation (NED) in patients with p ancreatic carcinoma have not been studied in detail. METHODS. Forty-four patients with pancreatic carcinoma who underwent surgic al resection at the Department of Surgery II, Nagoya University Hospital, w ere included in this study. For immunostaining, antibodies against neural c ell 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 analys is was performed by chi-square and Spearman rank correlation tests for grou p differences. Survival rates were calculated by the Kaplan-Meier method, a nd statistical significance was examined using the log rank test. Prognosti c factors were tested by univariate and multivariate analyses (proportional hazards regression model). P < 0.05 was considered statistically significa nt. RESULTS. Of 44 patients examined, 20 showed NED. The distribution of patien ts with positive or negative NED in terms of age, tumor differentiation, tu mor size, and the extent of tumor or lymph node metastasis showed no signif icant difference. The cumulative survival rates of patient groups according to NED status were then calculated, and NED positive patients showed a sig nificantly better survival rate (P < 0.05). Univariate and multivariate ana lyses of those factors showed that only NED status and TNM stage were signi ficantly related to overall survival. CONCLUSIONS. The current study suggests the significance of NED status in d etermining the outcome of patients with pancreatic adenocarcinoma, giving s olid evidence to encourage further studies on the differentiation and origi n of tumor cells in the pancreas. Cancer 2000;89:2230-6. (C) 2000 American Cancer Society.