The National Cancer Institute estimates that in 2009, approximately 40,870 new cases of rectal cancer will be diagnosed in the United States. The last part of the long intestine before the anus is the rectum. Sometimes colon and rectal cancer are grouped together and interchangeably described as colorectal cancer. Cancer that starts in these tissues is called rectal cancer. Once diagnosed, the cancer is then staged based on the extent and spread of the cancer, and this helps with guiding treatment and prognosis.
Stage 0
Stage 0 rectal cancer is also called carcinoma in situ. Abnormal, but non-cancerous, cells are found in the inner tissues of the rectum. Since these abnormal cells can turn into cancerous cells and spread to other tissues and parts of the body, it is important to detect these cells as early as possible.
Stage I
In this stage cancer has developed and has gone past the inner layer of the rectum to the next few layers and has spread to the inside wall of the rectum but not in the outer wall. This stage can also be called Dukes A rectal cancer. The five-year survival rate, which is the percentage of people alive five years after diagnosis, for this stage, is 90 percent, according to the American Cancer Society.
Stage II
Stage II rectal cancer involves cancer that has spread past the rectum to nearby tissue but has not reached the lymph nodes. Stage II cancer can also be called Dukes B rectal cancer. The five-year survival rate for Stage II rectal cancer is approximately 70 percent.
Stage III
In this stage, the cancer has spread to the lymph nodes but not to other parts or organs of the body. This is also called Dukes C rectal cancer. Stage III colon cancer has a 56 percent five-year survival rate, according to the American Cancer Society.
Stage IV
This is the most advanced stage of rectal cancer and can also be called metastatic rectal cancer, or Dukes D rectal cancer, according to the American Cancer Society. In this stage the cancer has spread to other parts of the body, commonly the liver, lungs, or ovaries. Metastatic rectal cancer has a 7 percent five-year survival rate.
