Prognostic score of gastric cancer determined by cDNA microarray.

PURPOSE To estimate gastric cancer patients' prognosis more comprehensively,we tried to develop a prognostic scoring system using a cDNA microarray. EXPERIMENTAL DESIGN RNA was extracted from tumor/normal paired samples of 43 patients with gastric cancer, and cDNA microarray hybridization was performed. RESULTS We selected 78 genes that were differentially expressed between aggressive and nonaggressive groups with respect to five conventional pathological factors. Next, we determined a coefficient for each gene. Thereafter a prognostic score was calculated by summing-up the value for each gene. It ranged from -47 to 201 with a median of 114. There were two peaks in its distribution. Ten of 11 patients who were alive with no evidence of recurrence >5 years after the operation showed a score of <100 points, whereas all 19 patients who died of disease showed >100 points. In 13 patients who were alive but the follow-up time was <5 years, 2 of the 3 patients with >100 points revealed recurrent disease during the follow-up. CONCLUSIONS These findings demonstrate that such a system with cDNA microarray can contribute to the comprehensive analysis of malignant behavior of the tumor and may provide accurate information on prognosis.