Bladder cancer

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Risk groups for early bladder cancer

Doctors classify bladder cancer that has not grown into the muscle layer of the bladder wall into risk groups. These risk groups are based on several factors, including the size and grade of the cancer. The risk groups allow the doctor to estimate the chance that the cancer will come back (recur) and continue to grow and spread (progress). Doctors also use the risk groups to help plan the best treatment.

Any non-invasive and non-muscle-invasive bladder cancers are classified as low, intermediate or high risk.

Low risk

Bladder cancer is low risk when:

  • there is only one low-grade tumour that is 3 cm or smaller
  • there is no carcinoma in situ (CIS)

Intermediate risk

Bladder cancer is intermediate risk when:

  • it comes back within 1 year and it is low-grade papillary carcinoma only within the lining of the bladder (non-invasive papillary carcinoma)
  • there is only 1 low-grade tumour and it is larger than 3 cm
  • there are many low-grade papillary carcinomas within the lining of the bladder
  • there is a high-grade tumour that is 3 cm or smaller
  • there is a low-grade tumour that has grown into the connective tissue layer of the bladder

High risk

Bladder cancer is high risk when:

  • there is a high-grade tumour that has grown into the connective tissue layer of the bladder
  • it comes back only within the lining of the bladder and it is high-grade papillary carcinoma
  • there is a high-grade tumour that is larger than 3 cm or there are many high-grade tumours
  • there is carcinoma in situ (CIS)
  • there are many tumours that are larger than 3 cm and low-grade papillary carcinomas
  • it is high grade and immunotherapy with bacillus Calmette-Guérin (BCG) did not work
  • it is a variant type of urothelial carcinoma
  • it has grown into small lymph vessels and blood vessels around the bladder (called lymphovascular invasion, or LVI)
  • it is high grade and has grown into the part of the urethra that runs through the prostate (called the prostatic urethra)


A description of a tumour that includes how different the cancer cells look from normal cells (differentiation), how quickly the cancer cells are growing and dividing, and how likely they are to spread.

Grades are based on different grading systems that are used for specific cancers. Some types of cancer do not have a specific grading system.

The process of examining and classifying tumours based on how cancer cells look and behave under the microscope is called grading.


A treatment that uses and strengthens the immune system to fight disease including cancer.

Immunotherapy is a type of biological therapy.


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