Flow cytometric DNA analysis of squamous cell carcinoma of the esophagus

Although an abnormal amount of cellular DNA content is known to occur in squamous cell carcinoma of the esophagus, the significance and clinical relevance of this finding have yet to be elucidated. Paraffin-embedded blocks from 77 patients with squamous cell carcinoma of the esophagus were dewaxed and made into a suspension by mechanical mincing and enzymatic digestion. The nuclei were stained with propidium iodide, and the DNA content evaluated with flow cytometric study. The DNA index (DI) and the coefficient of variation were determined and the results were compared with other pathologic prognostic features. DNA aneuploidy was identified in 70.1% of the specimens and found to correlate significantly with both histologic grading (P less than 0.025) and the incidence of postoperative recurrence (P less than 0.05). Although the 5-year survival was slightly better in the euploid group than in the aneuploid group (28.8% and 19.1%, respectively), this difference was not statistically significant (P greater than 0.1). There was no correlation of the DI with the extent of wall penetration by the tumor, the incidence of lymph node metastases, or the surgical staging, features previously shown to correlate with prognosis in patients with esophageal carcinoma.