Appendix Cancer

Appendix Cancer at a Glance

• The appendix is a pouch-like tube that is attached to the large intestine.
• The cause of appendix cancer is unknown, and no avoidable risk factors have been identified.
• Symptoms include appendicitis, bloating, pain in the abdomen or pelvis area, increased girth (size of the waistline), changes in bowel function, infertility.
• Surgery is the most common treatment for appendix cancer.

It is estimated that about 1% of colorectal cancer cases in the United States are primary appendix cancer, affecting about 1,500 people each year.

Appendix Cancer Cells

The appendix averages 10 cm in length and is considered part of the gastrointestinal tract. Generally thought to have no significant function in the body, the appendix may be a part of the lymphatic, exocrine, or endocrine systems.

Appendix cancer occurs when cells in the appendix become abnormal and multiply without control. These cells form a growth of tissue, called a tumor. A tumor can be benign or malignant. Another name for this type of cancer is appendiceal cancer.

Types of Appendix Tumors

There are a variety of tumors that can start in the appendix, including:
Carcinoid tumor-- An appendix carcinoid tumor most often occurs at the tip of the appendix. Approximately 66% of all appendix tumors are carcinoid tumors. This type of cancer usually causes no symptoms until it has spread to other organs, and often goes unnoticed until it is found during an examination or procedure performed for another reason.

Mucinous cystadenocarcinoma-- Mucinous cystadenocarcinoma is the most common non-carcinoid appendix tumor and accounts for approximately 20% of appendix cancer cases. This type of tumor produces a jelly-like substance called mucin that fills the abdominal cavity and can cause abdominal pain, bloating, and changes in bowel function.

Colonic-type Adenocarcinoma-- Colonic-type adenocarcinoma accounts for approximately 10% of appendix tumors and usually occurs at the base of the appendix. This type of tumor looks and behaves similarly to the most common type of colorectal cancer. It often goes unnoticed, and diagnosis is frequently made during or after surgery for appendicitis.

Signet-ring cell Adenocarcinoma-- Signet-ring cell adenocarcinoma (so called because under the microscope, the cell looks like it has a signet ring inside it) is very rare and considered to be more aggressive and more difficult to treat than other types of adenocarcinomas. This type of tumor usually occurs in the stomach or colon, and can cause appendicitis when it develops in the appendix.

Paraganglioma-- Paraganglioma is a rare tumor that develops from cells of the paraganglia, a collection of cells that come from nerve tissue that remains in small deposits after fetal (pre-birth) development, and is found near the adrenal glands and some blood vessels and nerves. This type of tumor is usually considered benign and is often successfully treated with the complete surgical removal of the tumor. Paraganglioma is very rare outside of the head and neck region.

Risk Factors

A risk factor is anything that increases a person’s chance of developing cancer. The cause of appendix cancer is unknown, and no avoidable risk factors have been identified. The following factor may raise a person’s risk of developing appendix cancer:

•   Age-- For a carcinoid tumor of the appendix, the average age at diagnosis is approximately 40. Carcinoid tumors are rare in children.

Symptoms

People with appendix cancer may experience the following symptoms.

• Appendicitis
• Ascites (fluid in the abdomen)
• Bloating
• Pain in the abdomen or pelvis area
• Increased girth (size of the waistline), with or without a protrusion of the navel (bellybutton)
• Changes in bowel function
• Infertility (the inability to have a child)