Predicting future tumour behaviour has always been a major task when treating bladder cancer. Ki67 monoclonal antibody has been reported to be a good marker of proliferative activity in a variety of tumours. We have studied the association of growth fractions defined by the monoclonal antibody with tumour grade, category and recurrence rate of superficial lesions in 34 patients with bladder cancer and 15 normal controls. Mean Ki67 indexes (% stained cells) were 0.07 +/- 0.02% in normal urothelium, 1.27 +/- 1.55% in grade 1, 12.23 +/- 8.32% in grade 2 and 16.42 +/- 11.82% in grade 3 tumours, while the values were 5.45 +/- 5.87%, 12.66 +/- 9.81% and 17.18 +/- 12.41% in categories pTa, pT1 and T2-T3 respectively. Recurrence and non-recurrence groups of patients showed indexes of 13.29 +/- 9.49% and 4.15 +/- 5.0% respectively. Statistically significant differences in Ki67 values between normal urothelium and tumour, between tumours of different grades and categories as well as between recurrence and non-recurrence groups of patients led to the conclusion that Ki67 monoclonal antibody is a good tool in defining tumour behaviour in bladder cancer.

In a case of endometrioid carcinoma of the prostate the expression of Leu7 and prostatic specific antigen (PSA) was studied immunohistochemically on paraffin sections. The same markers were studied in 14 cases of prostatic cancer and 14 cases of uterine endometrial carcinoma. Endometrioid carcinoma of the prostate was negative for Leu7 and PSA, while all prostatic cancer specimens were positive for the above markers. All uterine endometrial carcinomas were negative for PSA and only a small percentage of cells in 4 specimens were positive for Leu7. The absence of Leu7 and PSA in this case of endometrioid carcinoma strongly suggests a müllerian origin.