Histological grading of carcinoma in situ of the bladder: its clinical significance in patients who underwent intravesical mitomycin C and doxorubicin sequential therapy

Equivalent efficacy of mitomycin C plus doxorubicin instillation to bacillus Calmette-Guerin therapy for carcinoma in situ of the bladder

BACKGROUND

To elucidate the most efficient topical therapy for carcinoma in situ of the bladder, the efficacy of intravesical mitomycin C plus doxorubicin therapy was compared with bacillus Calmette-Guerin (BCG) therapy. The clinical behavior of the tumor was analysed according to the histological grade.

METHODS

Forty-two patients with carcinoma in situ of the bladder were randomized to intravesical BCG (21 patients) or mitomycin C plus doxorubicin sequential therapy (21 patients) as first line treatment. The non-responders underwent the subsequent instillation of the other intravesical therapy alternately. Of the patients, 27 had grade 2 and 15 had grade 3 cancer.

RESULTS

Both topical therapies were equally effective with initial response rates of 86% (18/21) for BCG and 81% (17/21) for mitomycin C plus doxorubicin, irrespective of the tumor grade. Of seven initial non-responders, five patients achieved a complete response by subsequent instillation, resulting in a total response rate of 95%. After a mean follow-up of 47 months, five patients (12%) developed disease progression. The progression rates were not different between the topical therapies, but were significantly higher in grade 3 than in grade 2 cases.

CONCLUSION

It appears likely that mitomycin C plus doxorubicin instillation has an equivalent efficacy to BCG as the initial therapy of carcinoma in situ and the combination of them would be the most efficient treatment for the disease. Moreover, histological grading would be clinically useful in defining the tumor characteristics and behavior of carcinoma in situ of the bladder.

Possible factors affecting response to intravesical bacillus Calmette-Guérin (Tokyo 172 strain) therapy for carcinoma in situ of the bladder: a multivariate analysis

To evaluate clinicopathological factors affecting response to intravesical instillation therapy with the bacillus Calmette-Guérin (BCG) Tokyo 172 strain for carcinoma in situ (CIS) of the bladder, we reviewed data for 84 patients treated between 1985 and 1996. Median follow-up was 56 months. The patients comprised three groups: primary (only the in situ lesion, 31 patients), subsequent (found after treatment of a gross neoplasm, 20), and concomitant (found together with a gross neoplasm, 33). A complete response was found in 62 (74%) of the 84 patients. Intravesical BCG therapy eradicated tumour cells in 74% of the primary group, 70% of the subsequent group, and 76% of the concomitant group. Multivariate logistic regression analysis revealed that the presence of gross haematuria and patient age were significantly associated with a complete response to the intravesical BCG therapy (p<0.05). On the other hand, gender, irritative bladder symptoms, type of extent of CIS, histological grade of CIS, BCG dose, and number of times BCG was given did not exert any significant influence. The 5-year recurrence rate was 33% for the 62 patients for whom a complete response was once achieved. Patients aged 60 or older had a higher probability of recurrence than those less than 60 years of age (p<0.05). Disease progression was found in 13% of the 84 patients and total cystectomy was performed in 19%. The present finding that patient age is related to the response to intravesical BCG therapy may point to a role for the reduced host immunocompetence in elderly individuals.

Strong correlation of basement membrane degradation with p53 inactivation and/or MDM2 overexpression in superficial urothelial carcinomas

PURPOSES

We investigated the relationships between the degradation of basement membrane underlying superficial urothelial carcinomas, including carcinoma in situ and the functional p53 loss caused by inactivation of p53 and the overexpression of mdm2 oncoprotein.

MATERIALS AND METHODS

Nuclear accumulations of p53 and mdm2 were examined immunohistochemically for 60 transitional cell carcinomas (primary lesions) and 13 accompanying (concomitant) carcinoma in situ lesions. Degradation of the basement membrane was defined as the reduction or total loss of type IV collagen expression. Whether there was up-regulation of MMP-1, MMP-2, and MMP-9 was analyzed immunohistochemically.

RESULTS

The frequency of the degradation of basement membrane underlying grade 1 pTa tumors was 0%, grade 2-3 pTa tumors 57.1%, and primary CIS lesions 83.3%. Nuclear over-accumulation of p53 was found in 48.3% and of mdm2 in 23.3% of the primary tumors. In pTa-pT1 carcinomas, nuclear staining of p53, mdm2, or both was highly correlated with degradation of the basement membrane underlying carcinomas (p = 0.00002). In the CIS lesions, the association of p53 nuclear staining with the destruction of type IV collagen expression was of borderline significance (p = 0.03). When mdm2 overexpression was considered as a molecular abnormality together with p53 inactivation, the correlation with the degradation of the basement membrane was highly significant (p = 0.00006). Moreover, the functional p53 loss was strongly associated with the up-regulation of matrix metalloproteinases (MMPs) (p = 0.0005). This finding was well correlated with the strong association of basement membrane degradation with up-regulation of MMPs (p = 0.000004).

CONCLUSIONS

Degradation of basement membranes underlying superficial carcinomas or CIS of the urothelium was significantly related to p53 inactivation, mdm2 overexpression, or both. The expression status of mdm2 should provide better information about the progression of superficial urothelial carcinomas than the status of p53 alone.