Superficial transitional cell carcinoma of the bladder is a common tum
our that can readily be removed surgically. However, it recurs in as m
any as 88% of patients, making it an ideal malignancy for immunoprophy
laxis or chemoprevention. Immunotherapy with bacille Calmette-Guerin (
BCG) is increasingly recognised as the most effective treatment for su
perficial bladder cancer, particularly for high grade tumours and carc
inoma in situ. Intravesical BCG instillation stimulates cellular immun
ity, cytokine production and antigen presentation. Unlike intravesical
chemotherapy, treatment with BCG induces protection from tumour recur
rent that persists for more than 5 years. Current optimal induction re
gimens use instillation of BCG once weekly for 6 weeks, followed by a
6-week rest period and 3 additional weekly instillations. This regimen
results in a complete response in carcinoma in situ in 82% of patient
s. In combination with maintenance BCG immunotherapy using instillatio
n once weekly for 3 weeks at 6-month intervals for 3 years, long term
disease-free status is achieved in 83% of patients. This regimen is fo
und to improve protection from recurrence by 33% when compared with a
single 6-week induction treatment, and further reduces disease progres
sion and cancer mortality. Controlled studies have demonstrated that B
CG is superior to standard chemotherapies, including thiotepa, doxorub
icin and mitomycin, and to alternative immunotherapies including inter
feron-alpha and keyhole limpet haemocyanin. However, these alternative
therapies provide treatment options for patients who have toxic react
ions or fail to respond to BCG.