Intravesical BCG-therapy: comparison of the adverse effects of Connaught (Toronto) and Pasteur (Paris) strains.

Introduction: Urologists have felt that the adverse effects of intravesical BCG-therapy have been move serious and move 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 (Pasteu r strain). Material and Methods: After endoscopic resection, 89 patients with stage Ta grade 1-2 recurrent or T1 grade 3 and/or CIS bladder tumour were treated w ith 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 an d/or fever less than 38 degreesC), moderate (requiring symptomatic treatmen t, reduction of the dose or an increased interval between instillations), a nd major (contraindication to continuation of treatment). Results: 74% of patients in group 1 presented at least one adverse effect v ersus 77% in group 2. The reasons for permanent discontinuation of BCG-ther apy in groups 1 and 2, respectively, were as follows: malaise during instil lation (1 vs 0), bladder irritation syndrome not controlled by symptomatic treatment (4 vs 5) and epididymitis (0 vs 1). Pulmonary tuberculosis was di agnosed in one patient from group 2, one year after the last instillation. The frequency and severity of adverse effects were not statistically differ ent between the two groups. The number of patients discontinuing BCG-therap y because of severe complications was also not statistically different betw een the two groups. Conclusion: This study did not reveal arty difference of toxicity between C onnaught and Pasteur strain in intravesical BCG-therapy of superficial blad der tumours.