EXPRESSION OF P53 PRODUCT IN CHINESE HUMAN BLADDER-CARCINOMA

Expression of p53 protein was examined in 67 cases of primary transiti onal cell carcinoma of the bladder and 6 normal controls using an immu nohistochemical method on paraffin sections. Positive nuclear staining for p53 in malignant cells was found in 34 (51 %) of the 67 cancer pa tients; no positive staining for p53 was detected in any of the normal controls or in the benign cells, including stromal and inflammatory c ells, within the tumor tissue. There were 8 positive cases (33 %) in 2 4 grade G1 tumors, 12 (48 %) in 25 G2 tumors and 14 (78 %) in 18 G3 tu mors. p53 protein was detected positively in 14 (36 %) of 39 superfici al tumors (Tis-T1) and in 20 (71 %) of 28 invasive tumors (T2-T4). Thu s, positive staining for p53 was found more frequently in poorly diffe rentiated tumors (chi-squared test: G3/G1 + G2 P < 0.0 1) and in invas ive tumors (chi-squared test: T2-T4/Tis-T1 P < 0.01). Expression of p5 3 was also closely associated with recurrence of tumors. Alterations i n p53 expression may be of prognostic value in cases of bladder transi tional cell carcinoma.