Résumé
PURPOSE: There are many prognostic factors in the recurrence and the progression of T1 superficial bladder cancer. Among these factors, microstaging evaluation in T1 bladder cancer may be of important value in patients with T1 superficial bladder cancer. To evaluate the usefulness of microstaging evaluation, we analyzed the microstage in T1 superficial bladder cancer and analyzed the recurrence rate and the progression rate of each microstage. MATERIALS AND METHODS: A retrospective analysis was done on 87 patients with T1 primary superficial bladder cancer managed in our hospital between January 1992 and April 1998. Microstages were assigned according to the following system: pT1a, invasion of lamina propria: pT1b, invasion to the level of the muscularis mucosa; pT1c, invasion through the muscularis mucosa but superficial to the muscularis propria. We analyzed the relationship between the microstage and the grade, the relationship between the recurrence or the progression of diseases and the grade of the tumor, the relationship between the grade or the microstage and the recurrence of diseases. All specimens were obtained from transurethral resection. RESULTS: The recurrence rates of pT1a, pT1b and pT1c were 9.1%(3/33), 40%(8/33) and 64.7%(22/33) respectively(p<0.001). The progression rates of pT1a, pT1b and pT1c were 0%(0/33), 10%(2/20) and 20.6%(7/34) respectively(p=0.005). The recurrence rates of grade I, grade II and grade III were 23.1%(3/13), 26.7%(12/45) and 62.1%(18/29) respectively(p=0.002). The progression rates of grade I, grade II and grade III were 7.7%(1/13), 4.4%(2/45) and 20.7%(6/29) respectively(p=0.062). pT1a, pT1b and pT1c were 21.2%(7/33), 20%(4/40) and 5.9%(2/34) in the patients of the grade I. pT1a, pT1b and pT1c were 69.7%(23/33), 50%(10/20) and 35.3%(12/34) in the grade II. pT1a, pT1b and pT1c were 9.1%(3/33), 30%(6/20) and 58.8%(20/34) in the grade III. Thus the relationship between the grade and the microstage was statistically significant(p=0.001). The recurrece rates of pT1a in the grade I, pT1b in the grade I and pT1c in the grade I were 14.3%(1/7), 0%(0/4) and 100%(2/2). The recurrence rates of pT1a in the grade II , pT1b in the grade II and pT1c in the grade II were 8.7%(2/23), 40%(4/10) and 50%(6/12). The recurrence rates of pT1a in the grade III, pT1b in the grade III and pT1c in the grade III were 0%(0/3), 66.7%(4/6) and 77.8%(14/20)(p=0.176). The progression rates of pT1a in the grade I, pT1b in the grade I and pT1c in the grade I were 0%(0/7), 0%(0/4) and 50%(1/2). The progression rates of pT1a in the grade II, pT1b in the grade II and pT1c in the grade II were 0%(0/23), 10%(1/10) and 8.3%(1/12). The progression rates of pT1a in the grade III, pT1b in the grade III and pT1c in the grade III were 0%(0/3), 16.7%(1/6) and 25%(5/20)(p=0.526). CONCLUSIONS: Microstaging in T1 superficial bladder cancer appears to be a significant prognostic factor in the recurrence and the progression of the diseases.