Highly aggressive behavior and poor prognosis of small-cell carcinoma in the alimentary tract: flow-cytometric analysis and immunohistochemical staining for the p53 protein and proliferating cell nuclear antigen.

The purpose of this study was to determine the clinical course, and effects of the histopathologic characteristics of specific tumors, including DNA contents and immunohistochemical aspects, in patients with small-cell carcinoma of the alimentary tract. Medical records of 14 patients who presented with small-cell carcinoma of the alimentary tract were retrospectively reviewed. Primary tumors were studied by immunohistochemical and flow cytometric analyses. Of these 14 small-cell carcinomas, 4 were esophageal, 8 gastric, and 2 colonic tumors. DNA aneuploidy was observed in 8 tumors. Staining for the p53 product was positive in 57.1% of all the tumors. The average proliferating cell nuclear antigen (PCNA) labeling rate (LR) was 72.4 +/- 11.6%. The average PCNA LR was significantly higher for the p53-positive group (p < 0.05). The estimated median survival was 253 days for all patients. Noncurative resection was associated with a significantly less favorable prognosis (p < 0.01). Distant metastases were observed in 13 of 14 patients. A higher PCNA LR of small-cell carcinoma may be an unfavorable characteristic of biological behavior. The patients with disseminated disease should undergo a symptomatically palliative operation combined with chemotherapy.