Retrospective analysis of the prognostic significance of DNA ploidy patterns and S-phase fraction in gastric carcinoma.

Paraffin-embedded tumor samples from 493 gastric carcinoma patients were analyzed by DNA flow cytometry. The results were correlated with clinicopathological findings and S-phase fractions measured by in vivo bromodeoxyuridine (BrdUrd) labeling. Of the 493 patients, 183 (37%), 225 (46%), and 85 (17%) showed diploidy, single DNA-aneuploidy, and DNA-multiploidy patterns, respectively. When the DNA histogram and all the clinicopathological parameters were entered simultaneously into the Cox regression model, DNA ploidy, liver metastasis, peritoneal dissemination, and nodal status emerged as independent prognostic parameters. The relative risk of death was twofold higher in single DNA-aneuploid and threefold higher in DNA-multiploid tumors than in DNA-diploid tumors. BrdUrd labeling indices (LIs) also proved to be an independent prognostic factor. Multiploid tumors showed the highest median BrdUrd LI associated with the most frequent peritoneal dissemination and liver metastasis. The simultaneous evaluation of DNA ploidy patterns and BrdUrd LIs gave more prognostic information than the determination of tumor DNA ploidy only. Namely, DNA diploid, together with low BrdUrd LIs, was associated with favorable prognosis, whereas DNA aneuploid with high BrdUrd LIs was related to the poorest prognosis. These results indicate that DNA ploidy and BrdUrd labeling indices may be possibly useful prognostic factors for gastric carcinoma.