BCG immunotherapy in superficial bladder cancer
Article published in Urologia Polska 2001/54/3.

authors

Anna Kołodziej, Janusz Dembowski

Katedra i Klinika Urologii Akademii Medycznej we Wrocławiu Kierownik kliniki: prof, dr hab. Jerzy Lorenz

keywords

urinary bladder, bladder carcinoma, BCG therapy

summary

Bacillus Calmcttc-Guerin (BCG) has been used for over 20 years now as adjuvant treatment for superficial bladder cancer. Al present, BCG immunotherapy for superficial bladder cancer is considered one of the most efficacious treatments and probably represents the most successful form of immunotherapy of solid tumours in humans. At the start of this new therapy in 1976 by Morales, a number of controversies existed. It was unknown which dose was optimal, which treatment scheme should be used and whether there was an optimal BCG strain. The working mechanism of BCG was not understood and there were problems about the toxicity of BCG intravesical therapy and how to deal with it. This article describes the problems, which are unsolved in BCG therapy and presented this, on which were reached consensus.

In searching for the appropriate BCG strain, the analysis of the results of 7 substrains has made clear that no particular strain has shown superiority over others. The standard treatment in every case is an initial six-week induction course with one installation every week. For tumors without a high recurrence or progression potential, this is usually sufficient. It is also clear that maintenance therapy is the therapy of choice for patients with carcinoma in situ and with high-risk tumors. However, the high rate of side effects associated with maintenance therapy and the prolonged duration of the BCG-induccd cystitis, which can result in discontinuation of the therapy for some patients, present a problem. Especially, that it is difficult to distinguish between therapy-related symptoms that may indicate efficacy of BCG and symptoms that may represent adverse effects. Because the overall side effects of BCG-instillations are more pronounced than of chemotherapeutic drugs, attempts have been made to reduce toxicity of BCG-therapy without affecting the efficacy of it. Several studies were made try to reduced toxicity by reducing the dose of BCG, but the topic of low-dose protocols is still controversial.

Intravesical therapy with BCG has proven to be very effective in the prophylaxis and treatment of superficial bladder tumors and carcinoma in situ. Controlled clinical studies from many countries have demonstrated the effectiveness of BCG therapy and in most series, BCG is superior to intravesical chemotherapy. Because of the more pronounced side effects, the risk and benefit for the individual patient should be considered in each case.

references

correspondence