LARGE INTESTIN (COLORECTAL) CANCER CAUSES SYMPTOMS EXAMINATIONS TREATMENTS

 Colorectal cancer (large intestine) - General

COLORECTAL CANCER (LARGE INTESTINE) - GENERAL
LARGE INTESTIN (COLORECTAL) CANCER CAUSES SYMPTOMS EXAMINATIONS TREATMENTS
As with all cancers, there is not one but several cancers of the large intestine. For convenience, however, we use the more common term 'colorectal cancer' in the singular, while 'colorectal cancer' should be referred to instead because of their variety.

Anatomy of the large intestine
Our digestive tract is made up of a series of organs. When we swallow food, it passes through the esophagus, the stomach, the small intestine, to finally arrive in the large intestine, itself composed of:

ascending colon (which directly follows the small intestine and at the beginning of which is the appendix)
transverse colon
descending colon
sigmoid colon
rectum (which ends at the anus)
In total, the large intestine is about 1.5 meters long. It is located in the abdominal cavity (the stomach in common parlance).

Colon diagram

The wall of the large intestine is made up of several concentric layers. From the inside to the outside, it has three layers:

the mucous layer
the muscle layer
the serous layer, formed by the peritoneum (a smooth, shiny membrane)
Some numbers
 

The infographic below has been produced based on figures from the Cancer Registry. The figures are transposed there in the form of graphs representing the number of new cases per year, the age groups most affected and the number of deaths due to this type of cancer.

Colorectal cancer is exceptional before the age of 40. Its incidence increases markedly from the age of fifty. The majority of colorectal cancers are found in the terminal part of the large intestine, although they can affect the entire intestine.

 
Classification
The degree to which cancer of the large intestine develops is determined by the layers of the intestinal wall affected and whether or not it has metastasized (in the lymph nodes or other parts of the body).

Cancer of the large intestine almost always starts from a growth (a benign polyp) in the lining. As it progresses, this cancer invades the deep layers of the intestinal wall.

When cancer cells reach lymph vessels, they can escape and colonize lymph nodes. If they reach the blood vessels, they can colonize distant organs (often the liver, sometimes the lungs or bones).

Two classifications exist to describe the stage of the disease: “Dukes” and “TMN”. If you hear the doctor using these terms about your cancer, have someone explain what they mean to you.