Control cells for image cytometric DNA analysis of esophageal tissue and the influence of preoperative treatment.

The nuclear DNA content of 4,960 normal cells in 30 esophagectomy specimens was assessed by image cytometry. In relation to intermediate squamous epithelial cells, the mean transmission values were 25.6% higher for basal squamous epithelial cells, 10.1% higher for fibroblasts and 16.2% lower for lymphocytes. The interslide coefficient of variation (CV) was similar for intermediate and basal squamous epithelial cells, 20.2% and 18.9%, respectively, while fibroblasts and lymphocytes displayed lower interslide CVs, 10.5% and 8.8%, respectively. In spite of their high interslide CVs, the mean DNA values of intermediate and basal squamous epithelial cells had the highest intraslide correlation. This correlation indicates that the preparative and analytical differences between slides that result in alterations in mean DNA values affect squamous epithelial cells of similar origin, size and shape in an analogous manner. Basal squamous epithelial cells replicate their DNA and contain more than the diploid amount; therefore, normal intermediate squamous epithelial cells are suggested as control cells to define the 2c reference value for further DNA studies on squamous epithelial lesions of the esophagus. Preoperative irradiation, with or without chemotherapy, did not alter the DNA values of the investigated control cells.