Expression of ras p21 oncogene product on human bladder tumors

The immunohistochemical localization of ras p21 oncogene product was examined in human bladder cancer. These bladder cancers consist of 52 superficial bladder tumors and 10 cases of invasive tumor. Five (9.6%) of 52 superficial tumors were demonstrated to be positive for ras p21 product. Two (20%) of 10 cases which showed deep tumor infiltration were demonstrated to be positive for ras p21 oncogene product. When we analyzed the incidence of positive staining for ras p21 with regard to histological grade of bladder cancer, 2 of 30 (7%) patients with G1, 4 of 26 (15%) with G2, and 1 of 6 (17%) with G3 had positive staining for the ras p21 oncogene product. One of five patients who showed positive staining on tumors had tumor recurrence 3 months later. The remaining 4 patients positive for the ras p21 oncogene product had no tendency for recurrence in 11-19 months' follow-up. Therefore, the incidence of detection of ras p21 oncogene product on superficial and deep infiltrating bladder tumor was similar and there was no significant correlation between the incidence of positive ras p21 staining and depth of invasion of bladder tumors or histological grade.