AbstractCytophotometric DNA analysis was performed on esophageal and gastric carcinomas. In 35 cases of mucosal and submucosal carcinoma of the esophagus, patients with types I and II (relatively regular in DNA distribution) had an uneventful postoperative course and no recurrence, whereas 3 of 15 (20%), and 5 of 9 (55.6%) with type III and type IV, respectively (widely scattered DNA distribution), died following a recurrence. Cytophotometric DNA analysis using biopsy specimens from 75 patients with esophageal cancer in various stages also showed a close relationship between the DNA distribution pattern and prognosis. However, the growth mode and the DNA ploidy of mucosal gastric cancer correlated well in the investigation of 66 cases. Thus, data of this method closely reflected the outcome in patients with digestive tract cancers. These results suggested the potential usefulness of cytophotometric DNA analysis for assessing the prognosis, even in the early stage of cancers.