Evaluation of the Predicted Proliferation Rate and Its Relation to the Tumor Marker Doubling Time in Gastric and Colorectal Cancer

Abstract

The tumor marker doubling time was calculated to evaluate the clinical significance of the predictedproliferation rate (S-phase fraction/DNA index) and the two indicators were compared them. Eighty seven patients with gastric cancer and eleven patients with colorectal cancer were studied. Tumor marker doubling time could be measured in 13.8% of gastric cancers and 45.5% of colorectal cancers. It tended to be short in the young patients and in poorly differentiated carcinomas. CEA doubling time was well correlated with the period from the operation to recurrence. CEA doubling time was significantly correlated with the predicted proliferation rate (r=0.65, p<0.05). Because the predicted proliferation rate can be determined from biopsied specimens, it is believed that the rate could be a useful indicator of malignancy not only in patients with negative tumor markers but also in patients with early gastric cancer.