Q | what is carcinoma in situ (CIS)?
A | CIS, otherwise known as flat bladder cancer, is grouped within the superficial bladder cancers.
This tumour is thought to be the product of an unstable bladder wall lining and the tumour tends to grow into the wall of the bladder rather than into the bladder cavity.
Some 25% of patients will have CIS associated with the more common superficial type of bladder cancer.
Although this is classed as a superficial cancer, there is a high risk (upto 50%) of this type of tumour becoming invasive.