Flow cytometric DNA analysis of submucosal carcinoma of the esophagus

Carcinoma of the esophagus confined to the submucosa presents clinicopathologic features different from those of either carcinoma limited to the mucosa or more advanced lesions. The present study was designed to find out whether or not analysis of DNA content would yield prognostic information allowing the clinical outcome of carcinoma of the esophagus confined to the submucosa to be predicted. Cell nuclear DNA content was determined by flow cytometry in paraffin-embedded blocks from 55 patients with carcinoma of the esophagus confined to the submucosa. This allowed classification of DNA content into diploid and aneuploid patterns based on combined DNA histogram and cytogram data. The aneuploid pattern included typical, multiple clone and small clone aneuploid subtypes, as classified by our new criteria. A DNA aneuploid pattern was identified in 26 cases (47.3%) and found to correlate significantly with lymph node metastasis (P < 0.01). The incidence of distant metastasis was significantly higher in the aneuploid (4/26) than in the diploid (0/29) group (P < 0.05). The mortality from cancer within two years of surgery was significantly higher in the aneuploid (4/26) than in the diploid (0/29) group (P < 0.05). In conclusion, flow-cytometric DNA analysis is a valuable method for predicting malignant potential in carcinoma of the esophagus confined to the submucosa.