為了解腫瘤分化在預測Tl期膀胱移形性細胞癌產生病程進展的意義，從1975年8月到1991年11月在台北榮民總醫院，共有118 位Tl期膀胱移形性細胞癌病患做病歷回顧及分析。118位病患中，14位是分化第1期佔11.9%，82位是分化第2期佔69.5 %，22位是分化第3期佔18.6 %。平均追蹤78.2個月。在追蹤期間有25位產生肌肉侵犯佔21.2%。這25位中有1位是分化第1期，15位是分化第2期，9位是分化第3期。在分化第1期只有l位病患在術後11個月有肌肉侵犯，平均發生肌肉侵犯的時間在分化第2期是47.8個月，在分化第3期是36.7個月。分化第3期膀胱移形性細胞癌比分化第l期及第2期在統計上有較高的機會產生肌肉侵犯。有2位分化第2期及1位分化第3期產生遠處轉移而沒有肌肉侵犯。病程進展的比率在TI 期膀胱移形性細胞癌是23.7%。其中分化第l期是7.1%，分化第2期是20.7%，分化第3期是45.5%。分化第3期膀胱移形性細胞癌比分化第l期及第2期在統計上有較高的機會產生病程進展。結論是腫瘤分化可用於預測Tl期膀胱移形性細胞癌的病程進展，較高的分化有較高的機會產生病程進展。

To understand the significance of tumor grade on predicting disease progression in stage TI transitional cell carcinoma of urinary bladder, from August 1975 to January 1991, the medical records of 118 patients for stage Ti transitional cell carcinoma (TCC) of the urinary bladder (UB) treated at Veterans General Hospital-Taipei with transurethral resection and post-operative adjuvant intravesical chemotherapy were retrospectively reviewed and analyzed. Of the 118 patients, 14 (11.9%) had grade 1, 82 (69.5%) had grade 2, and 22 (18.6%) had grade 3 tumor. The mean follow-up was 78.2 months. No patient had Ta (papilloma) or Tis (carcinoma in situ). During follow-up a total of 25 patients (21.2%) had muscle invasion recurrence. Of the 25, 1(7.1%) was with grade I, 15 (18.3%) with grade 2 and 9 (40.9%) with grade 3 tumor. The only patient in the grade I group developed muscle invasion ii months after operation. The mean interval to develop muscle invasion was 47.8 months in grade 2 and 36.7 months in grade 3, respectively. Stage TI TCC of UB with grade 3 had more chance of developing muscular invasion than grade 1 (p< 0.05) and grade 2 (p<0.05). Two patients (0.02%) in the grade 2 group and one patient (0.05%) in the grade 3 group developed distant metastasis without muscle invasion. Overall, the disease progression rate was 23.7 % (28/118) in stage Ti patients. On stratification, the rates were 7.1% in grade 1, 20.7% in grade 2 and 45.5 % in grade 3, respectively. The rate of disease progression was significantly higher in patients of grade 3 than grade 2 (p<0.05) and grade I (p<0.05). In conclusion, tumor grade may be used to predict disease progression after resection of stage Ti urinary bladder cancer. A higher grade of tumor has a higher incidence of disease progression.