Expression of p53 product in Chinese human bladder carcinoma.

Expression of p53 protein was examined in 67 cases of primary transitional cell carcinoma of the bladder and 6 normal controls using an immunohistochemical method on paraffin sections. Positive nuclear staining for p53 in malignant cells was found in 34 (51%) of the 67 cancer patients; no positive staining for p53 was detected in any of the normal controls or in the benign cells, including stromal and inflammatory cells, within the tumor tissue. There were 8 positive cases (33%) in 24 grade G1 tumors, 12 (48%) in 25 G2 tumors and 14 (78%) in 18 G3 tumors. p53 protein was detected positively in 14 (36%) of 39 superficial tumors (Tis-T1) and in 20 (71%) of 28 invasive tumors (T2-T4). Thus, positive staining for p53 was found more frequently in poorly differentiated tumors (chi-squared test: G3/G1 + G2 P < 0.01) and in invasive tumors (chi-squared test: T2-T4/Tis-T1 P < 0.01). Expression of p53 was also closely associated with recurrence of tumors. Alterations in p53 expression may be of prognostic value in cases of bladder transitional cell carcinoma.