[Intravesical BCG-therapy: comparison of side effects of Connaught (Toronto) and Pasteur (Paris) strains]

Urologists have felt that the adverse effects of intravesical BCG-therapy have been more serious and more frequent since the use of the Connaught strain. The objective of this retrospective study was to compare the toxicity of this new strain with that previously used in France (Pasteur strain).

After endoscopic resection, 89 patients with stage Ta grade 1-2 recurrent or T1 grade 3 and/or CIS bladder tumour were treated with 6 instillations of 150 mg of BCG Pasteur from 1992 to 1996 (50 patients: group 1) or 81 mg of BCG Connaught from January 1997 to December 1998 (39 patients: group 2). Adverse effects were classified as minor, lasting less than 48 hours (bladder irritation syndrome and/or macroscopic haematuria and/or fever less than 38 degrees C), moderate (requiring symptomatic treatment, reduction of the dose or an increased interval between instillations), and major (contraindication to continuation of treatment).

74% of patients in group 1 presented at least one adverse effect versus 77% in group 2. The reasons for permanent discontinuation of BCG-therapy in groups 1 and 2, respectively, were as follows: malaise during instillation (1 vs 0), bladder irritation syndrome not controlled by symptomatic treatment (4 vs 5) and epididymitis (0 vs 1). Pulmonary tuberculosis was diagnosed in one patient from group 2, one year after the last instillation. The frequency and severity of adverse effects were not statistically different between the two groups. The number of patients discontinuing BCG-therapy because of severe complications was also not statistically different between the two groups.

This study did not reveal any difference of toxicity between Connaught and Pasteur strain in intravesical BCG-therapy of superficial bladder tumours.