Purpose: The clinical behavior of carcinoma in situ of the bladder seems rather complicated. Although some have advocated the histological grading of carcinoma in situ, to our knowledge no sufficient clinical information has been reported. Therefore, we evaluated the clinical significance of histological grading of carcinoma in situ of the bladder.
Materials and methods: From January 1984 to December 1991, 58 patients with carcinoma in situ of the bladder were treated initially with intravesical mitomycin C and doxorubicin sequential therapy. Of the patients 20 had grade 2 and 38 had grade 3 anaplasia according to the modified World Health Organization grading system. Those who failed the initial therapy received another course of mitomycin C and doxorubicin sequential therapy or intravesical bacillus Calmette-Guerin.
Results: Following initial therapy, 13 patients (65%) with grade 2 and 28 (74%) with grade 3 disease achieved a complete response. Subsequent intravesical therapy resulted in complete response in 17 patients (85%) with grade 2 and 31 (82%) with grade 3 cancer. The local recurrence rate was higher in the grade 2 than in the grade 3 cases after a median followup of 48 months (range 10 to 84). The recurrent tumor configuration was significantly different between the 2 groups. Papillary cancer recurred only in grade 2 cases, while only nodular cancer recurred in grade 3 cases. The progression-free and survival curves were slightly higher in grade 2 than in grade 3 cases, although the difference was not significant.
Conclusions: There may be some difference in response to initial intravesical chemotherapy and the local recurrence rate between grades 2 and 3 carcinoma in situ, both of which are detrimental to grade 2 lesions. Moreover, it appears likely that grade 2 carcinoma in situ is a precursor of papillary high grade cancer and grade 3 carcinoma in situ is a precursor of nodular cancer. However, patient prognosis in the 2 groups was not significantly different.