Colon cancer - Get the facts

In the anatomy of the digestive system, the colon is another name for the large intestine. The main function of the colon appears to be extraction of water from feces. In mammals, it consists of the ascending colon, transverse colon, the descending colon, and the sigmoid colon. The colon from cecum to the mid-transverse colon is also known as the right colon. The remainder is known as the left colon.

Anatomy

The location of the parts of the colon are either in the abdominal cavity or behind it in the retroperitoneum. The colon in those areas is fixed in location.

Arterial supply to the colon comes from branches of the superior and inferior mesenteric arteries. Flow between these two systems communicates via a "marginal artery" that runs parallel to the colon for its entire length. Historically, it has been believed that the arc of Riolan, or the meandering mesenteric artery (of Moskowitz), is a variable vessel connecting the proximal SMA to the proximal IMA that can be extremely important if either vessel is occluded. However, recent studies conducted with improved imaging technology have questioned the actual existence of this vessel, with some experts calling for the abolition of the terms from future medical literature.

Venous drainage usually mirrors colonic arterial supply, with the inferior mesenteric vein draining into the splenic vein, and the superior mesenteric vein joining the splenic vein to form the portal vein that then enters the liver.

Lymphatic drainage from the entire colon and proximal two-thirds of the rectum is to the paraortic nodes that then drain into the cisterna chyli. The lymph from the remaining rectum and anus can either follow the same route, or drain to the internal illiac and superficial inguinal nodes. The dentate line only roughly marks this transition.

The ascending colon, on the right side of the abdomen, is about 12.5 cm long. It is the part of the colon from the cecum to the hepatic flexure (the turn of the colon by the liver). It is retroperitoneal in most humans. In ruminant grazing animals the cecum empties into the spiral colon. Anteriorly it is related to the coils of small intestine, the right edge of the greater omentum, and the anterior abdominal wall. Posteriorly, it is related to the iliacus, the iliolumbar ligament, the quadratus lumborum, the transverse abdominis, the diaphragm at the tip of the last rib; the lateral cutaneous, ilioinguinal, and iliohypogastric nerves; the iliac branches of the iliolumbar vessels, the fourth lumbar artery, and the right kidney

Cancer of the Colon

Colorectal cancer

Colorectal cancer, also called colon cancer or bowel cancer, includes cancerous growths in the colon, rectum and appendix. It is the third most common form of cancer and the second leading cause of cancer-related death in the Western world. Colorectal cancer causes 655,000 deaths worldwide per year. Many colorectal cancers are thought to arise from adenomatous polyps in the colon. These mushroom-like growths are usually benign, but some may develop into cancer over time. The majority of the time, the diagnosis of localized colon cancer is through colonoscopy. Therapy is usually through surgery, which in many cases is followed by chemotherapy. CLICK HERE FOR PRODUCT INFORMATION

Childhood cancers:

Cancer can also occur in young children and adolescents, but it is rare (about 150 cases per million yearly in the US). Statistics from the SEER program of the US NCI demonstrate that childhood cancers increased 19% between 1975 and 1990, mainly due to an increased incidence in acute leukemia. Since 1990, incidence rates have decreased.

The age of peak incidence of cancer in children occurs during the first year of life. Leukemia (usually ALL) is the most common infant malignancy (30%), followed by the central nervous system cancers and neuroblastoma. The remainder consists of Wilms' tumor, lymphomas, rhabdomyosarcoma (arising from muscle), retinoblastoma, osteosarcoma and Ewing's sarcoma. Teratoma is the most common tumor in this age group, but most teratomas are surgically removed while still benign, hence not necessarily cancer.

Female and male infants have essentially the same overall cancer incidence rates, but white infants have substantially higher cancer rates than black infants for most cancer types. Relative survival for infants is very good for neuroblastoma, Wilms' tumor and retinoblastoma, and fairly good (80%) for leukemia, but not for most other types of cancer. CLICK HERE FOR PRODUCT INFORMATION