NCCN Guidelines for Patients
Colon Cancer, Version 1.2017
A cancer stage is a rating by your doctors of the
extent of the cancer. It is used to plan which tests
may be needed and which treatments are best
for you. The AJCC (
ancer) staging system is used to stage colon
In the AJCC system, the letters T, N, and M describe
the areas of cancer growth. The T score describes
the growth of the primary tumor. The N score
describes nearby cancer growth within the colon or
lymph nodes. The M score tells if the cancer has
spread to distant sites.
The T, N, and M scores are combined to assign
the cancer a stage. There are five stages of colon
cancer. They are numbered 0, I (1), II (2), III (3), or IV
(4). The stages are defined as:
These cancers are also called carcinoma in situ of
the colon. The cancer has not grown beyond the first
layer of the colon wall. It is a noninvasive cancer.
More treatment may not be needed if all the cancer
was removed during an endoscopic polypectomy.
The cancer has grown into either the second or third
layer of the colon wall. There is no cancer in nearby
or distant sites.
The cancer has grown into the fourth layer of or
outside the colon wall. There is no cancer in nearby
or distant sites.
The cancer has spread from the colon to nearby
lymph nodes or there are tumor deposits. Tumor
deposits are small secondary tumors within the
The colon cancer has spread to distant organs.
Common distant sites include your liver and lungs.
Rating of the cancer stage is often done twice. The
first rating is based on tests before treatment and is
called the clinical stage. Exactly how far the cancer
has spread and how many lymph nodes have cancer
may not be known until after surgery. Thus, your
doctors will rate the cancer again after surgery. This
rating is called the pathologic stage.
The colon absorbs water from unused food in
The wall of the colon has four layers.
Colon cancer is a cancer of cells that line the
inner colon wall and make mucus.
Cancer cells form a tumor since they don’t grow
and die as normal cells do.
Cancer cells can spread to other body parts
through lymph or blood.
Most colon cancers start in polyps.
The cancer stage is a rating by doctors of the
extent of cancer.
Colon cancer basics