The rectum is the last six inches of the large intestine, and when cancer forms in these tissues, it is rectal cancer. Although the colon is the first six feet of the large intestine, sometimes colon cancer and rectal cancer are grouped together as colorectal cancers, and this term can be used to describe either cancer. Cancer is staged according to the extent and spread of the disease, and the staging helps guide diagnosis and treatment.
Stage 0 (Carcinoma in Situ)
Stage 0 is also called carcinoma in situ, which means the abnormal cells are contained and have not spread into the main tissues. These abnormal cells are not cancer yet but may become cancerous and are in the inner lining of the rectum.
Stage I
The National Cancer Institute defines Stage I rectal cancer as cancer that has spread from the inner lining of the rectum to the next two layers and is also found on the inner wall of the rectum. Cancer is not found on the outside rectum wall or anywhere outside the rectum. This stage may also be called Dukes A rectal cancer. The five-year survival rate, or the percentage of people who are still alive five years post-diagnosis, for this stage, is 90 percent.
Stage II
Stage II rectal cancer may also be referred to as Dukes B rectal cancer. In this stage, the cancer has grown outside the rectum to adjoining tissues but is not in any lymph nodes. The American Cancer Society estimates that the five-year survival rate for patients with Stage II rectal cancer is 70 percent.
Stage III
The next stage, Stage III, is when rectal cancer has spread to the lymph nodes but has not spread to any other organs in the body, according to the National Cancer Institute. Stage III rectal cancer is also known as Dukes C rectal cancer. The five-year survival rate for those with Stage III rectal cancer is 56 percent.
Stage IV
Stage IV rectal cancer may also be described as metastatic rectal cancer. This means the cancer has metastasized, or spread, to other organs in the body, like the lungs, liver or ovaries. This is also called Dukes D rectal cancer. According to the American Cancer Society, the five-year survival rate for patients with Stage IV rectal cancer is 7 percent.
Recurrent Rectal Cancer
While rectal cancer that recurs is not a stage of its own, recurrent rectal cancer may return locally (in the rectum), or it may be a distant recurrence (in a different organ, like the pelvis or lungs). The survival rate depends on the type of recurrence.
