Gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract and accessory organs of digestion, including the esophagus, stomach, biliary system, liver, pancreas, intestines, rectum and anus.
Anal Cancer
Anal cancer is a rare disease in which cancer cells form in the tissues of the anus, located at the end of the large intestine below the rectum. Most cancers of the anus are squamous cell cancers.
Colorectal Cancer
Most cases of colorectal cancer begin as polyps, or small growths on the inner wall of the large intestine, that become cancerous. The large intestine is comprised of the colon and the rectum, and colorectal cancers are sometimes named colon cancer or rectal cancer according to their place of origin.
Esophageal Cancer
The esophagus is a long, hollow tube that passes food from the throat to the stomach. Esophageal cancer forms in the cells that line the esophagus and is split into two types – adenocarcinoma, which begins in the flat cells that line the esophagus, and squamous cell carcinoma, which begins in the cells that create and release mucus and other fluids.
Gallbladder and Bile Duct Cancer
The gallbladder is a pear-shaped organ located beneath the liver that stores bile, a fluid made to aid fat digestion. Bile ducts are the thin tubes that transport bile from the liver (where it is created) to the gallbladder and small intestine. Cancer of the gallbladder begins in the organ’s innermost layer, most commonly in cells that create and release mucus and other fluids. Bile duct cancer forms in the cells throughout the bile duct network.
Gastrointestinal Stromal Tumor (GIST)
GISTs are rare cancers that originate in early forms of cells in the walls of the GI tract. These cells are known as interstitial cells of Cajal (ICCs) and are responsible for signaling muscles of the GI tract to contract and move food and liquid. GISTs can develop anywhere along the GI tract but most often start in the stomach.
Liver Cancer
The liver is responsible for filtering harmful substances from the blood, storing energy and aiding in digestion. Cancer of this organ is rare but increasingly common. Normally, cancer that is found in the liver has spread there from elsewhere in the body. The most common type of liver cancer is known as hepatocellular carcinoma, which often follows hepatitis or cirrhosis (scarring) of the liver.
Pancreatic Cancer
Pancreatic cancer begins in the tissues of the pancreas, an organ in the abdomen that releases enzymes that aid digestion and hormones that help manage blood sugar. There are two main types of pancreatic cancer, classified according to the cells in which they develop: endocrine pancreatic cancer, and the much more common exocrine pancreatic cancer.
Stomach (Gastric) Cancer
Stomach cancer, also known as gastric cancer, forms in the inner lining of the stomach, the sac-like organ that holds food and starts digestion. A main cause of stomach cancer is a bacterial infection called Helicobacter pylori.