Bladder Cancer Staging

Staging refers to the extent of the cancer once the cancer has been positively diagnosed. To provide the most effective treatment, a doctor must determine how extensively the cancer has spread. The stage of cancer may be determined at the time of diagnosis through cystoscopy or biopsy. Sometimes cancer staging requires other imaging techniques like a CAT scan, MRI or sonogram to determine if the cancer has spread (metastasized) to other parts of the body.

Cancer Staging System

Doctors use a system known as the TNM classification system for several types of cancer, including bladder cancer. The TNM system gives the doctor detailed information on the primary tumor and how much it has spread. The “T” represents the extent of the tumor, the “N” represents the amount of lymph node involvement, and the “M” represents the presence or absence of metastasis. The different stages can also be described numerically.

The following list describes the various stages of bladder cancer.

Stage 0: Cancer cells found on the inner surface of the bladder. This is the earliest stage of bladder cancer and is known as superficial cancer or carcinoma in situ (CIS).

Stage I: Cancer cells have penetrated the inner lining of the bladder but have not yet reached the muscle layer.

Stage II: Cancer cells have spread into the muscle layer.

Stage III: Cancer cells have spread beyond the bladder muscle and into the outer layer of tissue surrounding the bladder.

Stage IV: Cancer cells have spread towards the abdominal or pelvic wall. In men, the cancer cells may spread to the prostate. In women, the cancer cells may spread to the uterus or vagina. Cancer cells may have also spread to the lymph system and metastasized to other parts of the body.

The stage of bladder cancer is largely determined by how “deeply” the tumor has invaded.

Bladder Cancer Staging System

Grading Bladder Tumors

Another step in determining the best course of treatment is grading of the bladder tumors. Grading refers to the appearance of the cancer cells and is determined by a pathologist.

Tumors that contain normal-looking cells and still maintain some of the function of normal cells are known as differentiated tumors. Differentiated tumors are a low-grade tumor and grow slowly.

The poorly differentiated or undifferentiated tumors have abnormal shapes and lack organization. These are high-grade tumors and grow quickly. Carcinomas in situ tend to have high-grade components and a great risk of spreading.

While the grade of the tumor is important in deciding the treatment strategy, staging is a more important prognostic indicator in bladder cancer.

Bladder Cancer Prognosis

As with any cancer, early detection increases the chance for a better prognosis. Prognosis is dependent on many factors including patient health and response to treatment, tumor size, shape, and location, and staging and grading of the tumor.

Treatments for bladder cancers are based on the stage of cancer involvement. Treatment options include surgery, radiation therapy, chemotherapy, or biological therapy. Sometimes treatment options are combined for greater effectiveness.

Bladder Anatomy and Tumor Location

The bladder, located in the pelvic region, is a part of the urinary system. The kidneys produce urine and pass it through the ureters to the bladder. The bladder is the organ that stores urine. Stored urine is then released from the body via the urethra.

The bladder is made up of three layers:

  • inner layer (mucosa)
  • middle layer (connective tissue)
  • outer layer (smooth muscle)

The mucosa (or urothelial layer) is the innermost layer and is in direct contact with urine. The mucosa is made up of two types of cells: transitional and squamous. Transitional cells are the most susceptible to bladder cancers. Cancers of transitional cells are known as transitional cell carcinomas and account for more than ninety percent of all bladder cancers. Squamous cell carcinomas account for about eight percent of bladder cancers.

The next layer of the bladder is a layer of connective tissue that connects the mucosa to the third smooth muscle layer.

Superficial Bladder Cancer

Most of the bladder cancers originate in the first two layers of tissue and are called superficial bladder cancers. If the tumor protrudes out to the center of the bladder in the shape of a nipple it is known as papillary. If the tumor is flat and does not protrude in either direction, it is known as a carcinoma in situ. Carcinomas in situ can spread easily and quickly and have a great chance of penetrating beyond the first two layers of the bladder. Carcinomas in situ, once treated, have a high risk of recurrence.

Invasive Bladder Cancer

If the cancer penetrates through the first two layers to the third smooth muscle layer it is known as an invasive cancer. If the cancer penetrates all the way through the muscular wall, it can spread to nearby organs or lymph nodes. When cancer spreads beyond the bladder and into other organs, it is said to have metastasized.

Cancer is named after the location of its primary tumor. If the primary tumor began in the bladder it is known as bladder cancer. If the cancer has moved to another organ like the lungs it is identified as bladder cancer with metastasis to the lungs.


Beers, M. H.,