IMMUNOTHERAPY OF SUPERFICIAL BLADDER-CANCER

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.