What is Appendiceal Cancer?

What is Appendiceal Cancer?

Appendix cancer is extremely rare, affecting an estimated 600 to 1,000 Americans each year. Given the rarity of this disease, all patients with an appendix tumor should have their pathology formally reviewed and seek the advice of doctors who specialize in treating appendix cancer. Tumors that occur in the appendix comprise a large group of both benign and malignant diseases. Even among those tumors that are cancerous, it is important to note that not all of them behave the same way. Some appendiceal cancer types exhibit a much more aggressive behavior (those that are referred to at a microscopic level as “signet ring cells”) compared to others (referred to as “moderately differentiated” or “well-differentiated”). Appendix cancer is classified by the type of cells within the tumor.

Main types of Appendiceal Cancer:

• Carcinoid tumors: About half of appendix cancers are carcinoid tumors. Carcinoid tumors are most often found in women in their 40s. Most carcinoid tumors are small, and they often can be treated successfully.

• Non-carcinoid tumors: These tumors begin in the epithelial cells that line the inside of the appendix. Most epithelial cells produce mucin, a gelatinous material. These tumors have a tendency to spread, and the success of treatment depends on several factors.

• Pseudomyxoma peritonei (PMP): Mucin within the abdomen has few tumor cells, but cells may spread outside the appendix into the abdomen. Adenocarcinoid tumors, also known as goblet cell carcinomas, have characteristics similar to both carcinoid and adenocarcinoma tumors of the appendix. Most patients are diagnosed in their 50s.

In the early stages of the disease the appendix is removed, and tumor size is directly related to prognosis (outlook). Appendix tumors less than two centimeters have a low tendency to spread and patients generally have an excellent five-year survival rate, while tumors larger than 2.5 centimeters may require more aggressive treatment and patients have a lower survival rate.

Generally, appendix cancer stages are as follows:

• Localized: Cancer is found in the appendix, colon, rectum, small intestine and/or stomach only.

• Regional: Cancer has spread from the appendix, colon, rectum, stomach and/or small intestine to nearby tissues or lymph nodes.

• Metastatic: Cancer has spread to other parts of the body.

Unfortunately, appendix cancer often remains undiagnosed until it is unexpectedly found during or after abdominal surgery or when an abdominal mass is seen during a CT scan for an unrelated condition. This is further complicated by limited radiographic techniques which may reduce the ability for physicians to clearly see the abdomen and determine the extent of disease or even its origin. For these reasons, a majority of appendix cancer cases are not noticed until the disease is more advanced. These patients typically exhibit many tumor deposits spread throughout the abdominal cavity, accompanied by abundant fluid buildup (often leading to a swollen or distended abdomen), all of which originates from the appendix. Appendix cancer usually does not cause symptoms until it is in an advanced stage and has spread to other parts of the body. When symptoms are present, they vary from person to person and may include:

• Acute appendicitis: Most cases of appendix cancer are discovered during surgery for appendicitis
• Increase in abdomen size/girth, bloating
• Vague abdominal discomfort in the lower right abdomen
• Pelvic discomfort
• New hernias
• Bowel obstruction
• Ovarian masses
• Acute or chronic abdominal pain

If appendix cancer spreads to the liver, you may develop carcinoid syndrome. Symptoms include: • Flushing (redness or feeling of warmth in face and neck) • Shortness of breath or wheezing • Diarrhea • Heart valve disease on the right side • Pain or feeling for fullness in abdomen

If appendix cancer is suspected during abdominal surgery, the surgeon would take a tissue sample (biopsy) for a pathologist to review. Otherwise, the cancer may be diagnosed after your abdominal surgery as part of the routine pathology reading. In that case, another surgery would most likely be recommended to make sure all the cancerous tissue is removed. This surgical approach, called “debulking” or cytoreductive surgery, is the accepted standard for treating advanced appendix cancer. In addition to surgically removing all visible tumor in the abdomen, heated chemotherapy (called HIPEC, or hyperthermic intraperitoneal chemotherapy) can also be used during the operation to bathe the area and eliminate any remaining microscopic disease. This procedure is long and carries significant risk, and is therefore reserved for those patients who have the best chance of benefitting or being cured. Some patients with appendix cancer may have too much disease to remove in this manner, or may have other issues that would make this operation too dangerous to be a viable option. For these patients, systemic chemotherapy is an option, and it is thought to provide significant benefit both for symptom management and to prolong survival. It should be noted, however, that there is no consensus in the medical community about what chemotherapy would be the best option in this setting, though it is typically treated similarly to colon cancer. Studies to determine optimal treatment are ongoing.

Appendix cancer has no known cause. There are no known lifestyle changes that one can make to lower the risk of developing appendix cancer. Nevertheless, anything that increases your chance of getting appendix cancer is considered a risk factor. Not everyone with risk factors gets appendix cancer, however, if you have risk factors you should discuss them with your doctor. Risk factors include:

• Smoking tobacco
• Gender: women are more likely to develop carcinoid tumors than men
• Family history of appendix cancer
• Certain health conditions, such as atrophic gastritis, pernicious anemia or Zollinger-Ellison syndrome, which affect the stomach’s ability to make acid
• Having a family history of multiple endocrine neoplasia type 1 (MEN1) syndrome, a disorder also called endocrine adenomatosis and Wermer syndrome Additional Appendix Cancer

Additional Appendix Cancer Resources

For more information about Appendiceal Cancer, including Support Groups, please visit the MD Anderson Cancer Center web site.

Follow Dr. Cathy Eng, MD Anderson Cancer Center medical oncologist, Assoc. Director, Colorectal Center; colon, rectal, anal and appendiceal cancers, on Twitter.

Data Source:  MD Anderson Cancer Center, Houston TX