TY - JOUR T1 - What is the optimal regimen for BCG intravesical therapy? Are six weekly instillations necessary? JF - Eur Urol Y1 - 2000 A1 - A R Zlotta A1 - Van Vooren, J P A1 - Huygen, K A1 - Drowart, A A1 - M Decock A1 - M Pirson A1 - Fabienne Jurion A1 - Palfliet, K A1 - Olivier J Denis A1 - J Simon A1 - C C Schulman KW - Administration, Intravesical KW - Aged KW - Antigens, Bacterial KW - BCG Vaccine KW - Carcinoma, Transitional Cell KW - Cystoscopy KW - Dose-Response Relationship, Drug KW - Drug Administration Schedule KW - Female KW - Follow-Up Studies KW - Humans KW - Immunotherapy KW - Lymphocyte Count KW - Male KW - middle aged KW - Mycobacterium bovis KW - T-Lymphocytes KW - Urinary Bladder Neoplasms AB -

OBJECTIVE: For more than 20 years, BCG intravesical therapy schedule has included 6 weekly instillations. Very few studies have, however, analyzed the rationale of this regimen. We previously demonstrated that intravesical BCG induced an increased peripheral immune response against mycobacterial antigens as compared to pretreatment values. In the present work, we have studied the weekly evolution of this immune response induced by intravesical BCG instillations.

MATERIALS AND METHODS: The evolution of the lymphoproliferative response of peripheral blood mononuclear cells against BCG culture filtrate (CF), tuberculin (PPD) and BCG extract (EXT) was tested before, every week during the BCG instillations and at 3 and 6 months follow-up in 9 patients with superficial bladder cancer treated with 6 weekly BCG instillations. Lymphoproliferation was measured by means of a tritiated thymidine incorporation test.

RESULTS: A significant increase in the lymphoproliferative response against PPD, CF and EXT was observed in 9, 8 and 7 of the 9 patients, respectively, as compared to pre-BCG values. The maximal lymphoproliferation was achieved after 4 instillations in 4/5 patients initially reactive against mycobacterial antigens whereas 2 of 4 initially nonreactive patients required 6 instillations. At 6 months' follow-up, lymphoproliferation against BCG and the other mycobacterial antigens returned to pre-BCG values in all patients. In 3 patients who received additional instillations because of tumor recurrence within 1 year of follow-up, the maximum immune response was observed already after 2 instillations.

CONCLUSION: In most patients, the maximal peripheral immune response is already observed after 4 weekly instillations. However, patients not previously immunized against mycobacterial antigens may require 6 weekly instillations to achieve a maximum stimulation level. Our data support the need to further evaluate the role of this status before starting BCG instillations. It could be of interest to study whether 6 BCG instillations are really necessary in patients previously immune against mycobacterial antigens.

VL - 37 CP - 4 M3 - 10.1159/000020170 ER -