Bladder cancer acts differently in each person. The grade of your cancer describes how the cancer cells look under a microscope. Knowing how the cells look will help your doctor predict how fast the cancer may grow and spread. The stage of your cancer describes the size of a tumor and where and how deeply it has spread.
The place where cancer originates is called the primary site. Bladder cancer can spread from the primary site to other parts of the body. Cancer that has spread is called metastatic cancer. When a cancer spreads, it is said to have metastasized.
The TNM system is a standard system for describing the extent of a cancer's growth. Here's what the letters stand for in the TNM system:
T describes how deeply a tumor has invaded the bladder and nearby tissues.
N tells whether the lymph nodes near the tumor have cancer in them.
M tells whether the cancer has spread to other organs in the body, such as your lungs or bones.
Numerical values are assigned to each of the T, N, and M categories to help further describe the stage of the cancer.
The TNM system consists of several different components. Each one is given a score. Then the scores are grouped to determine an overall stage for your cancer. With the TNM system, there are 2 different types of stages. The first is the clinical stage. Your oncologist will determine this from a physical exam, biopsies, and imaging tests, such as a CT scan. The clinical stage is used to decide what type of treatment is called for. Later, the tissue that is removed during surgery will be examined, and the cancer will be given a new stage called its pathologic stage. This stage is more accurate in terms of predicting treatment outcome and survival.
Each TNM category, with its assigned numerical value, falls into one of these stages. The number assigned to the letter shows how extensively the cancer has spread. A higher number means it has spread more deeply. Based on the stage of your cancer, your doctor will plan the best treatment for you.
Stage 0. This stage means that cancer cells are found only on the surface of the inner lining of the bladder. Your doctor may call this stage superficial cancer or carcinoma in situ. TNM terms for this stage: Ta, Tis, N0, M0.
Stage I. The cancer cells are found to have grown deeper into the inner lining of the bladder. The cells haven't spread into the bladder muscle. TNM terms for this stage: T1, N0, M0.
Stage II. The cancer cells have spread to the muscle of the bladder. TNM terms for this stage: T2 (a, b), N0, M0.
Stage III. The cancer cells have spread through the muscular wall of the bladder to the layer of fatty tissue surrounding the bladder. In men, cancer cells may have spread to the prostate gland. In women, they may have spread to the uterus or vagina. TNM terms for this stage: T3 (a, b), or T4a, N0, and M0.
Stage IV. The cancer has spread to the wall of the abdomen or to the wall of the pelvis, or cancer cells have spread to lymph nodes and/or other parts of the body far away from the bladder, such as the lungs. TNM terms for this stage: T4b, N0, M0; or any T, N 1, 2, 3 M0; or any T, any N, M1.