Intravesical BCG Therapy

BCG is a useful treatment for some patients with bladder cancer

BCG is weakened tuberculosis bacteria. When it is placed into the bladder it activates your immune system to attack bladder cancer cells. BCG is used most commonly following a diagnosis of superficial bladder cancer where there is concern that you may have a higher than usual risk of cancer recurrence. It reduces the risk of the cancer recurring and progressing to a more serious stage.

BCG is usually given once per week for six weeks (induction course). Following the induction course there may be a BCG maintenance program prescribed. This is a two year program of BCG which is given weekly for three weeks at initially three months following induction then six monthly out to two years.


BCG is administered in the department of urology at Wellington Hospital. A nurse will insert a thin catheter into your urethra then flush a solution of BCG into your bladder. You retain the BCG in the bladder for one hour before emptying your bladder. This is not a painful procedure.


A urine sample is obtained several days prior to each instillation of BCG.


BCG is usually very well tolerated. Most patients experience some urinary frequency and urgency. Mild flu-like symptoms are quite common. These side effects usually become more noticeable as the number of cycles of therapy increase due to your immune system rapidly recognising the bacteria and mounting a response to it. If side effects are quite pronounced then the dose of BCG is reduced and this usually improves symptoms without significant loss of treatment efficacy.

Serious adverse effects are very rare. The most serious of these is the development of widespread BCG infection; this would require a several month treatment with anti-tubercular drugs. For this reason BCG is not given to people with weakened immune systems or those taking immune suppressing drugs such as azathioprine or high dose steroids.

Your scheduled program of flexible cystoscopy will continue during the BCG course, usually at 3-6 month intervals.