Superficial bladder cancer: state of the art

Intravesical Bacillus Calmette-Guérin versus epirubicin for Ta and T1 bladder cancer

BACKGROUND

Bladder cancer accounts for approximately 4.4% of adult malignancies, and approximately 80% of bladder cancer presents initially as transitional cell carcinoma that is confined to the urothelium (stage Ta) or lamina propria (stage T1). Intravesical administration of Bacillus Calmette-Guérin (BCG) and epirubicin (EPI) has been proven to reduce tumour recurrence and prevent or delay progression to muscle invasion and metastases. However, comparison of the effectiveness and safety of intravesical BCG and EPI in bladder cancer has yet to be explored.

OBJECTIVES

To compare the effectiveness and safety of BCG with EPI in the treatment of Ta and T1 bladder cancer.

SEARCH STRATEGY

A comprehensive search of MEDLINE (1966 to April 2010), EMBASE (1980 to April 2010), Health Services Technology, Administration, and Research (HealthSTAR), the Cochrane Central Register of Controlled Trials (CENTRAL), CancerLit, and Database of Abstracts of Reviews of Effectiveness (DARE), was performed, and handsearching of relevant journals was undertaken.

SELECTION CRITERIA

All randomised or quasi-randomised trials (in which allocation was obtained by alternation - e.g., alternate medical records, date of birth, or other predictable methods) in patients with Ta or T1 bladder cancer that compared intravesical BCG with EPI were included. No language restrictions were applied.

DATA COLLECTION AND ANALYSIS

Trial eligibility, methodological quality and data extraction were assessed independently by two reviewers. We compared dichotomous outcomes (frequency of tumour recurrence, progressive disease by stage, mortality, distant metastases, local and systemic adverse effects, treatment delayed or stopped due to adverse effects) using risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Five trials of 1111 participants were included in this review. For BCG, 549 patients were treated, and 562 with EPI. Of the evaluated patients, 35.5% (195/549) in the BCG group and 51.4% (289/562) in the EPI group had tumour recurrence (P < 0.05). For disease progression (BCG, 44/549; EPI, 58/562) and distant metastases (BCG, 23/487; EPI, 31/495), there were no significant differences (P = 0.19 and P = 0.29, respectively). Only two trials, including 769 patients, had sufficient data for us to analyze disease-specific (BCG, 22/383; EPI, 26/386) and overall mortality (BCG, 125/383; EPI, 147/386). Neither comparison was significant (P = 0.93 and P = 0.12, respectively). In four studies reporting toxicity, BCG was associated with significantly more drug-induced cystitis [BCG, 54.1% (232/429); EPI, 31.7% (140/441)] and haematuria [BCG, 30.8% (132/429); EPI, 16.1% (71/440)]. Similarly, in three studies reporting systemic toxicity, BCG had significantly higher toxicity than the EPI (34.8% (134/385) versus 1.3% (5/393), respectively). In a meta-analysis comparing 'treatment delayed or stopped' (BCG, 40/431; EPI, 33/441), there was no significant difference between BCG and EPI treatments (P = 0.82).

AUTHORS' CONCLUSIONS

The data from the present meta-analysis indicate that intravesical BCG treatment is more efficacious than EPI in reducing tumour recurrence for Ta and T1 bladder cancer. However, BCG appears to be associated with a higher incidence of adverse effects, such as drug-induced cystitis, haematuria and systemic toxicity, than EPI. The overall quality of the evidence is rather low. Well-designed, high quality randomised controlled trials with good allocation concealment are required.

Chemoprevention of superficial bladder cancer

Patients who have bladder cancer with superficial disease are at high risk for recurrence but low risk for progression to muscle invasive disease and are regularly monitored with cystoscopy to detect recurrent tumors. This clinical setting (high recurrence rate, excellent surveillance, and low risk of progression in stage) provides an ideal setting for secondary chemoprevention. Vitamins, difluoromethylornithine, and cyclooxygenase inhibitors have demonstrated activity in preclinical models of bladder cancer. Limited clinical data suggests that vitamins and their analogs may be useful for decreasing the rate of tumor recurrence in patients with superficial bladder cancer. Ongoing clinical trials are exploring the roles of fenretinide, difluoromethylornithine, and celecoxib in the treatment of patients with a history of superficial bladder cancer.

Retinoids in the prevention of bladder cancer

Superficial bladder cancer has an unpredictable natural history but in many patients it has a tendency for multiple recurrences over many years. Chemoprevention approaches are ideally tested in this type of tumor and may delay or prevent recurrences of superficial bladder cancer or prevent progression to invasive disease. Vitamin A and its derivatives, the retinoids, have been studied in detail in this disease. This article reviews the data on this subject and includes in vitro and in vivo preclinical studies as well as the clinical studies performed in the secondary prevention of this disease.

Significance of the preoperative intravesical instillation of doxorubicin and the oral administration of 5-fluorouracil in preventing recurrence after a transurethral resection of superficial bladder cancer. Kyushu University Urological Oncology Group

BACKGROUND

The postoperative intravesical instillation of doxorubicin (ADM) has a preventative effect on recurrence after a transurethral resection (TUR) of superficial bladder cancer. However, the significance of preoperative ADM instillation remains unclear. Although the oral administration of 5-fluorouracil (5-FU) has been observed to show some clinical response against bladder cancer, its preventative effect on the recurrence of superficial bladder cancer after TUR is unknown.

METHODS

Patients were randomized into 4 groups. All 4 groups received postoperative ADM instillation. In addition, patients in groups C and D received preoperative ADM instillation, whereas patients in groups B and D additionally received oral 5-FU postoperatively. The nonrecurrence rate and side effects were both compared among the 4 groups.

RESULTS

Of the 282 patients registered, 200 were evaluable, with a median follow-up period of 21.4 months. There were no significant differences in the characteristics of the patients among the 4 groups. Group C (pre- and postoperative ADM) showed a significantly longer disease-free interval than group A (postoperative ADM alone). However, there was no significant difference in the disease-free interval between groups A and B (postoperative ADM plus 5-FU), or between groups C and D (pre- and postoperative ADM plus 5-FU). Bladder irritation symptoms were the most frequently noted side effect encountered in all groups, but the severity was generally mild.

CONCLUSIONS

Preoperative ADM instillation was found to prevent recurrence to a greater extent than the usual postoperative instillation alone, whereas oral 5-FU was found to have no additional beneficial effect on the disease-free interval in patients with superficial bladder cancer.