Treatment of superficial bladder tumors: Achievements and needs

Objective: The therapeutic objectives in the initial treatment of superfici al tumors are to remove completely the tumor, to assess the need for furthe r therapy and to plan the follow-up. Methods/Results: The EORTC Genitourina ry Group assessed the percentage of patients with recurrence at 3 months (3 RR) after complete resection of all visible lesions taking into account the institution, the number of tumors at presentation and the year of treatmen t. The 3RR was considered for 18 institutions. For single tumors, the 3RR v aried from 6 to 36% and for multiple tumors from 7 to 75%. The 3RR by numbe r of tumors was 8.7% for single tumors, 21% for 2-5 tumors and 32.2% for >5 tumors. The 3RR by year of entry for single tumors ranged from 21.0 to 43. 8% during 1975-1978, from 6.3 to 12.7% during 1984-1986 and from 3 to 5.3% during 1987-1989. For multiple tumors it ranged from 50.0 to 61.5% during 1 975-1978, from 20.2 to 27.3% during 1979-1983 and from 14.4 to 24.6% during 1984-1986. The use of more refined instruments probably led to the decreas ing percentage of the 3RR in more recent years, the large variation between institutions remains unexplained. The bladder's unique location renders it s mucosa accessible to instillation of chemotherapeutic and immunotherapeut ic agents. Cytostatics can be instilled into the bladder hours after surger y without severe complications. A single early instillation within 6 h afte r transurethral resection (TUR) in patients with a solitary bladder tumor c ategory T-a/T(1)G(1) to G(3) could reduce the recurrence rate per year by n early 50%. The superiority of any of the commonly used intravesical drugs h as never been demonstrated; the time to initiate therapy is important for t reatment outcome. Optimal results can be achieved by initiating treatment e arly (within 24 h after TUR) and for a duration of 6 months, and maintenanc e (>6 months) for patients with a delayed first instillation (>7 days after TUR). Bacillus Calmette-Guerin (BCG) immunotherapy has been confirmed to b e highly effective in the reduction of tumor recurrence, the treatment of r esidual papillary transitional cell carcinoma and the treatment of carcinom a in situ (CIS). The response rate in the treatment of the papillary diseas e averages 55%, and for CIS 73%. In the prevention of tumor recurrence the relative benefit of BCG is 45%. A direct prospective randomized comparison of BCG with intravesical chemotherapy has found it to be significantly supe rior to thiotepa, to doxorubicin and to mitomycin C when only patients with intermediate and high risk for recurrence were treated. In studies includi ng patients with low recurrence risk, no advantage for BCG was found. Clini cal trials showed no superiority of BCG immunotherapy to chemotherapy in pr eventing progression to greater than or equal to T-2. Conclusions: Investig ation of the concept of chemoimmunotherapy up to now lacked evidence of adv antages for this approach. Preventive regulatory measures directed to decre ase tobacco smoking and some occupational exposures to aromatic amines may contribute to the reduction of bladder cancer. Bladder cancer is a multiste p process making this tumor a candidate for chemoprevention. To date, retin oids are the best-studied chemopreventive agents achieving mixed clinical r esults in superficial bladder tumors. The potent apoptosis-inducing retinoi d fenretinide is currently in the phase ill trials. The follow-up of patien ts with all types of superficial tumors must be lifelong; unfortunately cys toscopy cannot be replaced yet by the control of any markers present or not in the urine. There is hope this may change in the near future. Copyright (C) 2000 S. Karger AG, Basel.