THE SIGNIFICANCE OF TUMOR GRADE IN PREDICTING DISEASE PROGRESSION IN STAGE TA TRANSITIONAL-CELL CARCINOMA OF THE URINARY-BLADDER

Objective To determine the significance of tumour grade in predicting disease progression in stage Ta transitional cell carcinoma (TCC) of t he urinary bladder. Patients and methods From August 1975 to January 1 991, 140 patients (121 men and 19 women, mean age 64.2 years, range 30 -83) with stage Ta TCC of the urinary bladder were treated at the Vete rans General Hospital-Taipei by transurethral resection and post-opera tive adjuvant intravesical chemotherapy. There were 48 patients (34%) with grade 1, 78 patients (56%) with grade 2 and 14 patients (10%) wit h grade 3 tumours. Disease progression and muscle invasion were assess ed during a mean follow-up of 74.3 months and related to grade, urine cytology and the number and location of tumours. Results A total of 10 patients (7%) had tumour recurrence which invaded the muscle, of whom one had grade 1, six had grade 2 and three had grade 3 tumours. The p atient with a grade 1 tumour developed muscle invasion within 16 month s of surgery. The mean internal to the development of muscle invasion was 49.2 months in patients with grade 2 and 39.4 months with grade 3 tumour. In patients with stage Ta TCC, a grade 3 tumour was more likel y to progress to muscle invasion (21%) than was a grade 1 (2.1%; P<0.0 5) or grade 2 (7.7%; P<0.05) tumour. One patient with a grade 2 and on e patient with grade 3 tumour developed distant metastases without mus cle invasion. Overall, the disease progression rate was 8.6% (12/140) in stage Ta TCC. Disease progression was more common with grade 3 (28. 5%) than with grade 2 (9.0%; P<0.05) and grade 1 (2.1%; P<0.05) tumour s. Conclusion Tumour grade may be used to predict disease progression after resection of stage Ta urinary bladder cancer. A higher grade of tumour was associated with a higher incidence of disease progression.