Colon Cancer Stages | MedGuidance

Colon is a tube that connects small intestine with the rectum. It is also known as large intestine and is almost 5 to 6 feet in length. The purpose of colon is to store and process waste material. Every once in a while, contents of colon are passed on to the rectum and then are excreted from the body. Colon cancer may begin with adenomatous polyps. A number of methods of classifying the stages of colon cancer are present. Among them Dukes staging and TNM classification are the most used.

Colon Cancer Stages—Dukes' Classification

Astler-Coller, Modified Astler-Coller (MAC) and Turnbull stagings are some other names which Dukes’ classification is sometimes referred to. The origins of most colon cancers can be found in mucosa which is the lining inside the colon. As the cancer develops, it grows both inside and outside. The cancer grows in the lumen at the inside and in the wall of the colon on the outside. As it develops, cancer can grow out through the colon wall and attack other cells, tissues and organs. It can also spread to lymph nodes and liver. According to Dukes’ classification, stages of cancer can be divided into the following stages:

Stage	Description
Stage A	Tumors do not reach the muscularis propria but attack the submucosa through the muscularis mucosae.
Stage B1	Tumors have reached muscularis propria.
Stage B2	The smooth muscle layer present in serosa has also been attacked and invaded by the tumors.
Stage C1	Tumors involve less than four positive nodes and have invaded muscularis propria as well.
Stage C2	Tumors involve equal to or more than four nodes and have completely invaded the smooth layer and further into serosa.
Stage D	Tumors have metastasized to distant organs.

Colon Cancer Stages—TNM Classification

TNM classifying is the most popular method of colorectal cancer classification used by physicians. The method has been created by the American Joint Committee on Cancer (AJCC). There are three pieces of information provided by the classification:

T shows the degree of which the primary tumor has developed into the colon wall and its growth in the nearby tissues and organs.
N points out the lymph node involvement in the cancer. Lymph node is an immune system cell collection which has a significant role in fighting infections.
M describes whether or not the cancer has metastasized to other parts of the body. The colon cancer mostly spreads to liver and lungs, though it can metastasize to almost all organs.

Stage Grouping

Once the T, N and M information has been collected, it is used to determine the stage of the patient by the stage grouping. The stages evaluated from the classification are numbered from I to IV, with stage I being the lowest stage of cancer, while IV being the most serious stage.

Stage		Description	Survival Rate
0		The stage is called carcinoma in situ. In this stage abnormal, cells which may or may not be cancer are found in the inner most layer of the wall of the colon.	---
I		Tumor has been formed in the colon wall’s innermost layer and has moved to the submucosa and even to the colon wall muscle layer.	74%
II	IIA	Cancer has reached the outer layer of the wall of the colon called serosa through its muscle layer.	67%
	IIB	Cancer has invaded serosa which is the outermost layer of the colon wall completely.	59%
	IIB	The cancer has outgrown the colon wall and has developed into the organs near the colon.	37%
III	IIIA	Cancer has penetrated up to colon wall’s muscle layer thorough mucosa and submucosa and has also affected around three lymph nodes. Or it has spread only till the submucosa but has affected 4 to 6 lymph nodes.	73%
	IIIB	The outermost colon wall layerhas been affected by the cancer, but it has not invaded any other organ. The cancer has also affected around tissues near the lymph nodes. Or cancer has reached up till the farthest colon wall layer, i.e. serosa, but not penetrated outside the colon wall. It has invaded 4 to 6 lymph nodes. Or cancer has invaded mucosa and submucosa and has spread to colon wall’s muscle layer. It also has invaded more than 7 lymph nodes near the colon wall.	46%
	IIIC	Cancer tumor has affected 4 to 6 lymph nodes in addition to penetrating through the serosa but has not affected nearby organs. Or cancer tumor has invaded more than 7 lymph nodes near the colon wall and not metastasized to other organs. Its spread has affected the mucosa, submucosa, muscle layer and serosa of the colon wall. Or cancer has invaded two or more lymph nodes as well as tissues surrounding those lymph nodes. It has completely spread through the serosa and also has invaded organs near the colon.	28%
IV	IVA	Cancer cells have spread completely through the colon and have also invaded organs and lymph nodes near the colon. They have also metastasized to an organ or lymph node which is distant from the colon. The distant organ can be liver, lung or ovary.	6%
IV	IVB	Cancer has completely grown out of the colon and affected nodes and organs near the colon. The cancer cells have also developed in more than one distant organ.	6%

There are very few symptoms in the initial stages of colon cancer. Moreover, symptoms and signs also vary because of the position and size of the cancer in colon. However, you should know the most common symptoms which include a change in your bowel habits and the uniformity of your stool, a sudden loss of weight, blood in your stool, any pain or cramp causing your discomfort. As soon as you notice any of the symptoms, you must consult your physician as soon as possible.

If you want to know more information about colon cancer, you can see the video:

Colon Cancer Stages—Dukes' Classification

Colon Cancer Stages—TNM Classification

Stage Grouping

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