bowel cancer

By the term "colon cancer" is generally meant cancer of the large intestine (colon carcinoma) and cancer of the rectum (rectal carcinoma). Together they are also called colorectal cancer.

The term "carcinoma" refers to cancers that originate from the integumentary tissue of the skin or mucous membrane, in this case from the lining of the large intestine.

Cancer in the small intestine is rare, as is cancer in the anus (anal cancer). Both of these cancers differ in origin and treatment from colon cancer and rectal cancer.

Colon cancer can occur anywhere in the large intestine and rectum. More often it occurs in the lower sections of the large intestine, namely in the lower 30 - 40 cm. The precursors of cancer in many cases are the so-called polyps. These are initially benign, often mushroom-like neoplasms in the large intestine. Approximately 90% colon cancer occurs as a result of the fact that these polyps degenerate, their cells turn into cancer cells.

Colon cancer most often arises from the glandular cells of the intestinal mucosa. This is the layer of cells that covers the inner wall of the intestine. While the tumor is still small, it is limited in this area. With increasing growth, the tumor penetrates the underlying intestinal wall and subsequently affects the surrounding tissues and lymph nodes. In this case, single tumor cells can detach from it and enter the blood and lymphatic vessels. With blood and lymph, they enter other organs. There they can settle down and multiply again, so there are daughter tumors (metastases). Metastases can appear in the liver, lungs. Spread into the peritoneum is also possible and can lead to significant accumulation of fluid in the abdomen (ascites).