Gastrointestinal cancer refers to malignant

Malignant

Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...

 conditions of the gastrointestinal tract

Gastrointestinal tract

The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....

, including the esophagus, stomach, biliary system, pancreas, bowels, and anus. The symptoms relate to the organ affected, and can include obstruction (leading to difficulty swallowing or defecating), abnormal bleeding, or other associated problems. The diagnosis often requires endoscopy

Endoscopy

Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an endoscope , an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ...

, followed by biopsy

Biopsy

A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...

 of suspicious tissue. The treatment depends on the location of the tumor, as well as the type of cancer cell and whether it has invaded other tissues or spread elsewhere in the body. This also determines the prognosis.

Types

Types of gastrointestinal cancer include:

• Esophageal cancer
  Esophageal cancer
  Esophageal cancer is malignancy of the esophagus. There are various subtypes, primarily squamous cell cancer and adenocarcinoma . Squamous cell cancer arises from the cells that line the upper part of the esophagus...
  
  
• Stomach cancer
  Stomach cancer
  Gastric cancer, commonly referred to as stomach cancer, can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs, lymph nodes, and the liver...
  
   (also called gastric cancer)
• liver cancer
  Hepatocellular carcinoma
  Hepatocellular carcinoma is the most common type of liver cancer. Most cases of HCC are secondary to either a viral hepatitide infection or cirrhosis .Compared to other cancers, HCC is quite a rare tumor in the United States...
  
   (also called hepatocellular carcinoma, HCC, and hepatoma)
• Gallbladder cancer
  Gallbladder cancer
  Gallbladder cancer is a relatively uncommon cancer. It has peculiar geographical distribution being common in central and South America, central and eastern Europe, Japan and northern India; it is also common in certain ethnic groups e.g. Native American Indians and Hispanics. If it is diagnosed...
  
  
• Pancreatic cancer
  Pancreatic cancer
  Pancreatic cancer refers to a malignant neoplasm of the pancreas. The most common type of pancreatic cancer, accounting for 95% of these tumors is adenocarcinoma, which arises within the exocrine component of the pancreas. A minority arises from the islet cells and is classified as a...
  
  
• Colorectal cancer
  Colorectal cancer
  Colorectal cancer, commonly known as bowel cancer, is a cancer caused by uncontrolled cell growth , in the colon, rectum, or vermiform appendix. Colorectal cancer is clinically distinct from anal cancer, which affects the anus....
  
   (also called colon cancer, bowel cancer, and rectal cancer)
• Anal cancer
  Anal cancer
  Anal cancer is a type of cancer which arises from the anus, the distal orifice of the gastrointestinal tract. It is a distinct entity from the more common colorectal cancer. The etiology, risk factors, clinical progression, staging, and treatment are all different. Anal cancer is typically a...
  
  
• Gastrointestinal stromal tumor
  Gastrointestinal stromal tumor
  A gastrointestinal stromal tumor is one of the most common mesenchymal tumors of the gastrointestinal tract...
  
  s (GIST)

Prognosis

Prognosis is variable,and depends almost entirely on the specific type of cancer. Esophageal cancer has a dismal prognosis, largely because it is often detected late, while colon cancer has an excellent prognosis,when detected early. Pancreatic cancer also has a very poor prognosis, with only 5% of patients surviving more than 5 years after diagnosis.