Colorectal & Gastrointestinal Cancer Diagnosis

What is anal cancer?

Anal cancer is cancer that starts in the anus. The anus is the opening at the end of your rectum. The rectum is the last part of your large intestine where solid waste from food (stool) is stored. Stool leaves your body through the anus when you have a bowel movement.

Anal cancer is fairly rare. It spreads slowly and is easy to treat before it spreads. This cancer can start anywhere in the anus. Where it starts determines the kind of cancer it is.

• Squamous cell carcinoma. This is the most common type of anal cancer. It starts in cells that line the anal canal and grow into the deeper tissue.
• Cloacogenic carcinoma. Almost all the rest of anal cancers are tumors that start in cells lining the area between the anus and rectum. Cloacogenic carcinoma looks different than squamous cell cancers, but behaves similarly and is treated the same.
• Adenocarcinoma. This type of anal cancer is rare in the United States. It starts in the anal glands below the anal surface and is often more advanced when it is found.
• Skin cancer. Some cancers form outside the anus in the perianal area. This area is mainly skin. The tumors here are skin cancers and are treated as skin cancer.

The cause of anal cancer is unclear. However, there is a link between anal cancer and the human papillomavirus or HPV infection. HPV is a sexually transmitted virus that has been linked to other cancers as well.

What is appendix cancer?

This cancer forms in the appendix, a part of the digestive system located near where the large intestine and small intestine come together. The type of appendix cancers depends on the type of cells. The main types are:

• Carcinoid tumors
• Non-carcinoid tumors
• Pseudomyxoma peritonei (PMP)

Appendix cancer is rare, with fewer than 1,000 Americans diagnosed each year. Roughly half of diagnoses occur when a person has surgery for acute appendicitis. Others cases of appendix cancer are discovered during CT scans for unrelated conditions.

What is bile duct cancer?

Also called cholangiocarcinoma (CCA), bile duct cancer is a rare cancer growth in one of the ducts that carry bile from the liver to the small intestine.

Bile duct cancers are slow-growing. They don't spread (metastasize) quickly. The exact cause of CCA isn't known. However, many of these tumors are already quite advanced by the time they are found.

CCA may start anywhere along the bile ducts. These tumors block off the bile ducts. Both men and women are affected. Most people are older than 65. People with the following health problems may have a higher chance of developing CCA:

• Bile duct (choledochal) cysts
• Chronic biliary and liver inflammation
• History of infection with parasitic worms, liver flukes
• Primary sclerosing cholangitis
• Ulcerative colitis

What is colorectal cancer?

Colon and rectal cancer, or colorectal cancer, is when cancer forms in the large intestine (colon) or the rectum (end of the colon).

In the United States, colorectal cancer is one of the leading causes of deaths due to cancer. Early diagnosis can often lead to a complete cure. Almost all colon cancers start in the lining of the colon and rectum. When doctors talk about colorectal cancer, this is usually what they are talking about.

There is no single cause of colon cancer. Nearly all colon cancers begin as noncancerous (benign) polyps, which slowly develop into cancer.

What is gallbladder cancer?

Gallbladder cancer is a rare form of cancer that starts in the gallbladder, a small organ located under the liver. Almost all cases are adenocarcinomas, a cancer that starts in gland-like cells that line many surfaces of the body, including the gallbladder.

What is intestinal cancer?

Also called small intestine cancer or small bowel cancer, intestinal cancer begins in the small intestine. There are a few main types of small intestine cancers:

• Adenocarcinomas, which start in the gland cells lining the inside of the intestine
• Carcinoid tumors, which is the most common type of small intestine tumor
• Lymphomas, which start in immune cells called lymphocytes.
• Sarcomas, affect connective tissues, such as muscle.

The small intestine makes up the largest part of the digestive tract, but small intestine cancers are not as common as colon or stomach cancer.

What is liver cancer?

Hepatocellular carcinoma is cancer that starts in the liver. Hepatocellular carcinoma accounts for most liver cancers. This type of cancer occurs more often in men than women. It is usually diagnosed in people age 50 or older.

Hepatocellular carcinoma is not the same as metastatic liver cancer, which starts in another organ (such as the breast or colon) and spreads to the liver.

In most cases, the cause of liver cancer is long-term damage and scarring of the liver (cirrhosis). Cirrhosis may be caused by:

• Alcohol abuse
• Autoimmune diseases of the liver
• Hepatitis B or hepatitis C virus infection
• Inflammation of the liver that is long-term (chronic)
• Iron overload in the body (hemochromatosis)

People with hepatitis B or C are at high risk of liver cancer, even if they do not develop cirrhosis.

What is pancreatic cancer?

The pancreas is a large organ behind the stomach. It makes and releases enzymes into the intestines that help the body digest and absorb food, especially fats. The pancreas also makes and releases insulin and glucagon. These are hormones that help the body control blood sugar levels.

There are different types of pancreatic cancers. The type depends on the cell the cancer develops in. Examples include:

• Adenocarcinoma, the most common type of pancreatic cancer
• Glucagonoma
• Insulinoma
• islet cell tumor
• VIPoma

What is stomach (gastric) cancer?

Several types of cancer can occur in the stomach. The most common type is called adenocarcinoma. It starts from one of the cell types found in the lining of the stomach.

Adenocarcinoma is a common cancer of the digestive tract. It is not very common in the United States. It is diagnosed much more often in people in eastern Asia, parts of South America, and eastern and central Europe. It occurs most often in men over age 40.

The number of people in the United States who develop this cancer has decreased over the years. Experts think this decrease may be in part because people are eating less salted, cured, and smoked foods.