What is Appendiceal Cancer?

Appendix cancer is extremely rare, affecting an estimated 600 to 1,000 Americans each year.  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 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”).

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.

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.

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.

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