The present study was undertaken to evaluate the nuclear
DNA content of
esophageal cancer cells consequent on the process of growth and progression of the
cancer. In experimental animal studies, 47
esophageal cancers were induced in male Wistar rats by
oral administration of
N-amyl-N-methylnitrosamine (AMN) and were analysed in the study of ploidy patterns. The study was also carried out to determine the
DNA content in the ploidy patterns in man. Primary
tumors associated 421 metastatic lymph nodes in the 62 patients with thoracic
esophageal cancer were subjected for the study of ploidy patterns. The nuclear
DNA content was determined by means of flow cytometry. In the study of the experimentally-induced
esophageal cancer in rats,
aneuploidy was found in 18% at a depth of submucosa, 30% at proprial muscle, 59% at adventitia, and in 50% at a depth of neighboring structures, respectively. Clinically in man, the incidence of
DNA diploidy and
aneuploidy in the 62 primary
cancers was 56% and 44%, respectively. In the 421 metastatic lymph nodes, diploid was found in 73% and
aneuploid in 11%, while the combination of diploid and
aneuploid was observed in 16%. Difference in the
DNA index (DI) between the primary
cancers and metastatic lymph nodes was found in 29 cases (46.8%), and the difference increased with progression of the
cancer. Two hundred and ninety seven metastatic lymph nodes of 29 cases were subdivided into 4 groups based on the extent of the cancerous nests, and the DI value was found to be increased in proportion to the extension. With the results, the DI value of
esophageal cancer appeared to be changed dependently by the variation of cell populations in the
cancer or in the
DNA content of the
cancer cells.