Staging is one of the most important steps in the process of treating cancer. It helps the medical professionals understand the extent to which the disease has progressed and what treatments can be opted for. This article talks about the stages of colon cancer from least to most fatal.

Stage 0
In this stage, cancerous cells are only found in the mucosa or the inner lining of the colon or rectum.

Stage I
When the cancer spreads out from the mucosa and affects the muscular layer or submucosa of the colon or rectum, it is said to be in stage 1.

Stage II
Stage II colon cancer can be divided into two substages. These are as follows.

1. Stage IIA
In stage IIA, the cancer will have developed beyond the wall of the colon or rectum. However, this is also one of the stages of colon cancer where the abnormal cancerous cells have not spread to nearby tissue and nymph nodes.

2. Stage IIB
When the cancer grows and spreads to the lining of the abdomen, also known as the visceral peritoneum, it is said to be in stage IIB. The visceral peritoneum is the membrane that keeps the abdominal organs in place. This is also one of the stages of colon cancer in which the lymph nodes have not yet been affected.

3. Stage IIC
When the tumor grows and spreads through the colon or rectum wall into nearby structures, it is staged as IIC. However, it has not spread to the nearby lymph nodes or anywhere else in the body.

Stage III
Stage III of this condition is classed as follows:

1. Stage IIIA
In this stage, the cancer will have grown and spread into the muscular layers of the intestine. It is also likely to have spread to 1 to 3 lymph nodes and to other tissues near the colon or rectum. It has, however, not spread to other parts of the body.

2. Stage IIIB
In addition to metastasizing beyond the bowel wall, the cancer will have spread to nearby organs, 1 to 3 lymph nodes and tissues. However, cancer has not spread to other, distant body parts yet.

3. Stage IIIC
Although, in this stage too the cancer has not spread to distant parts of the body, it has grown and spread to affect 4 or more lymph nodes.

Stage IV
Stage IV of this condition is further classed as:

1. Stage IVA
The cancer would have spread to a single, distant part of the body such as the lungs or liver.

2. Stage IVB
The cancer has spread to more than one part of the body.

3. Stage IVC
In addition to the peritoneum, colon cancer is extremely likely to have metastasized to other places in the body. The organs slowly begin to shut down in this stage due to the malign cells.