DNA ploidy in early gastric cancer and its relationship to prognosis.

The relationship between DNA ploidy and clinical prognosis was determined in 65 patients who underwent gastroectomy for early gastric cancer. Of the 65 patients, 16 had intramucosal and 49 submucosal tumours. Five-year survival rates were 100 and 79.6% for patients with intramucosal and submucosal tumours respectively. Diploid tumours were observed more frequently among the patients with intramucosal neoplasms. Among the patients with submucosal invasion, the presence of polyploid cells (greater than or equal to 6c) in less than 10% of the malignant population was associated with a superior survival at 5 years, than those with greater than or equal to 10% of polyploid cells (92.1% vs. 36.3%). When the macroscopic type and the ploidy status were evaluated together, patients who had greater than or equal to 10% of cells with DNA greater than or equal to 6 c and a protruding type of tumour, had a 5 year survival rate of only 12.5%. Finally when factors such as the level of wall invasion, percentage of polyploid cells, type of histogram, and macroscopic type were evaluated by multiple regression analysis, macroscopic type and percentage of polyploid cells were the only significant prognostic factors. On the basis of these findings, the DNA ploidy pattern and the macroscopic type may be useful markers of patients who will develop recurrence.