Gastrointestinal (GI) Cancer Types

November 22, 2024

This page was reviewed under our medical and editorial policy by Laleh Melstrom, M.D., M.S., associate professor of surgery and immuno-oncology, Division of Surgical Oncology, Department of Surgery, City of Hope^® Cancer Center Duarte

Gastrointestinal (GI) cancers are a group of diseases that affect different parts of the digestive system, including the esophagus, stomach, liver, pancreas and intestines. Although each type of gastrointestinal cancer is unique and needs specific treatments, they all interfere with how the digestive system works.

Common Types of GI Cancer

While cancer may occur anywhere in the GI tract, some gastrointestinal cancer types are more common.

Esophageal cancer: This cancer starts in the esophagus, the tube that carries food from the throat to the stomach. It often begins to grow in the inner lining of the esophageal wall and spreads outward. The two main subtypes are adenocarcinoma and squamous cell carcinoma.

Stomach (gastric) cancer: Stomach cancer begins in the stomach lining and may spread to other parts of the body. This type of cancer is often slow-growing. Early precancerous changes may not cause any symptoms, which may allow them to go undetected.

Colorectal cancer: This type of cancer starts in the colon or rectum. Many kinds of colorectal cancer begin as polyps or growths on the inner lining of the intestine. Colon polyps are common and usually noncancerous, but certain types may develop into cancer over time.

Liver cancer: Liver cancer starts in the liver cells and may be primary (originating in the liver) or secondary (having spread from another organ). There are several subtypes of primary liver cancer; however, the most common form in adults is hepatocellular carcinoma (HCC).

Pancreatic cancer: This GI cancer type begins in the pancreas, an organ that aids digestion and regulates blood sugar. Pancreatic cancer most often affects exocrine cells, which produce digestive enzymes. Less often, it may affect the endocrine cells, which make hormones like insulin and glucagon to regulate blood sugar.

Rare GI Cancers

While esophageal, stomach, colorectal, liver and pancreatic cancers are among the most common GI cancers, several less common types also affect the digestive system. Here are some less common types of gastrointestinal cancer.

Appendix Cancer: This type of cancer forms in the cells of the appendix. Appendiceal cancer affects about one or two people for every million in the United States each year, but researchers believe it’s becoming more common.

Bile duct cancer: This cancer occurs in the bile ducts, which are small tubes that carry bile from the liver to the small intestine. While it may begin in any part of the bile duct system, nearly all are cholangiocarcinomas, a type of adenocarcinoma that starts in gland cells that line the ducts.

Gallbladder cancer: Gallbladder cancer starts in the gallbladder, a small organ beneath the liver that stores bile. Nearly all gallbladder cancers are adenocarcinomas that start in the gland-like cells that line the inside of the organ. Other subtypes, such as adenosquamous carcinomas, squamous cell carcinomas and carcinosarcomas, are even rarer.

Small intestine cancer: This rare cancer occurs in the small intestine (bowel), which connects the stomach to the large intestine and breaks down food. Most small intestine cancers develop in the duodenum, the foot-long, first part of the small intestine that attaches to the stomach.

Carcinoid tumors: Carcinoid tumors are a type of neuroendocrine tumor that may occur in the GI tract. The neuroendocrine system’s cells act like nerve cells (neurons) and hormone-making (endocrine) cells. They are scattered throughout the body, but are mainly concentrated in the digestive tract, where they help control the flow of digestive juice and how fast food moves.