What are the Grades and Stages of Muscle Invasive Bladder Cancer?
Grade and stage are two important ways to measure and describe how cancer develops. A tumor grade tells how aggressive the cancer cells are. A tumor stage tells how much the cancer has spread.
Grading is one of the ways to know if the cancer will return. It also tells us how quickly the cancer may grow and/or spread.
Tumors can be low or high grade. High-grade tumor cells are very abnormal, poorly organized and more serious. They are the most aggressive and more likely to grow into the bladder muscle.
The tumor stage tells how much of the bladder tissue has the cancer. Doctors can tell the stage of bladder cancer by taking a small sample of the tumor. This is called a biopsy. A pathologist in a lab examines the sample under a microscope and determines the stage of the cancer.
The stages of bladder cancer are:
- Ta: Tumor on the bladder lining that does not enter the muscle
- Tis: Carcinoma in situ-A high-grade cancer-it looks like a reddish, velvety patch on the bladder lining
- T1: Tumor goes through the bladder lining but does not reach the muscle layer
- T2: Tumor grows into the muscle layer of the bladder
- T3: Tumor goes past the muscle layer into tissues surrounding the bladder
- T4: Tumor has spread to nearby structures such as lymph nodes and the prostate in men or the vagina in females.
Layers of the bladder
What to Expect with MIBC
Muscle invasive bladder cancer is a serious and more advanced stage of bladder cancer. MIBC is when the cancer has grown far into the wall of the bladder (Stages T2 and beyond).
For patients with MIBC, the overall prognosis (how the disease may progress) has not changed in the last 30 years. In patients who undergo cystectomy (surgical removal or partial removal of the bladder), the cancer return rate can be from 20-30% for stage T2. The cancer return rate can be 40% for T3, greater than 50% for T4 and usually higher when lymph nodes are involved. If bladder cancer does recur, it most often will happen within the first two years after bladder surgery.