Appendix Cancer: What You Should Know

Medically Reviewed By: Nelya Melnitchouk, MD, MSc

Appendix cancer, or appendiceal cancer, is an incredibly rare cancer, occurring in roughly one person out of every 100,000. Despite its rarity, appendiceal tumors come in a variety of forms and presents very differently from person to person. There are treatment options for appendiceal cancer, and it usually comes with a relatively good prognosis.

Here, Nelya Melnitchouk, MD, MSc, director of the Peritoneal Surface Malignancy Program at Brigham and Women’s Hospital and Dana-Farber Cancer Center, answers some of the most common questions about appendiceal cancer.

What is appendiceal cancer?

Appendiceal cancer is a disease where cells in the appendix begin to replicate abnormally. This abnormal replication results in the formation of tumors in the appendix.

How is appendiceal cancer found?

Patients can develop abdominal pain or bloating or fluid in the abdomen, which can then lead to a diagnosis of appendiceal cancer. But more often, it is discovered accidentally. A patient will often come in for an unrelated reason, such as presumed appendicitis or another condition that will warrant scans, and that is when the cancer is caught. Appendiceal cancer can also be found during other surgeries.

Once cancer is discovered, a biopsy is performed in order to determine if the problem is actually appendiceal cancer and what kind of appendiceal cancer it is.

What types of tumors occur in appendiceal cancer?

There are several different types of tumors that occur in appendiceal cancer:

  • Carcinoid tumors are the most common, making up half of appendiceal cancers. Carcinoid tumors are typically not very aggressive and can be relatively easy to treat so long as they have not metastasized.
  • Low-grade appendiceal mucinous neoplasm, a type of tumor that comes from the appendix’s mucus producing cells and is incredibly slow growing. This type of tumor causes an overproduction of mucin which is a jelly-like substance produced in the appendix. If not caught, the overproduction of mucin can cause the appendix to burst, spilling that mucin into the abdominal cavity. This causes an extremely rare condition called pseudomyxoma peritonei.
  • Appendix adenocarcinomas and goblet cell carcinoids can also occur and tend to be more aggressive tumors requiring more aggressive treatment.

How is appendiceal cancer treated?

Surgery — specifically, a procedure called an appendectomy where the entire appendix is removed — is the most common treatment for appendiceal cancer if discovered early. If the cancer has not spread and is a slow growing type of cancer, an appendectomy is usually enough to cure the patient.

If the tumor is more aggressive, larger surgery where parts of the colon are removed alongside the appendix are often the first course of action. Usually this can be done laparoscopically, through small incisions. If the tumor has spread to the lining of abdominal cavity, a large surgery, called cytoreductive surgery, is needed. Hyperthermic intraperitoneal chemotherapy (HIPEC) usually accompanies these larger surgeries. HIPEC involves heated chemotherapy drugs that are circulated in the abdominal cavity during surgery in order to treat any remaining cancer cells. It is believed that the combination of the heat and the direct application of the drugs is more effective than surgery alone in some of these cases.

Systemic (intravenous) chemotherapy is also used for more aggressive tumors, but usually after surgery or if surgery is not an option.

Are there any causes or risk factors with appendiceal cancer?

At the moment, there are no definitive causes or risk factors associated with appendiceal cancer. The risk factors for colon cancer seem to be related to appendiceal cancer, but even that relationship is unclear at the moment.

What else should I know?

Keep in mind that appendiceal cancer is a very rare cancer and only accounts for 0.5% of all tumors that start in the gastrointestinal tract. Even so, if you have any concerns or worries about your appendix, do not be afraid to seek out medical advice and ask whatever questions you need.