Is there more than one type of appendiceal cancer?
There's a spectrum of different types of cancer that people get in their appendix. The cancers we see most often are mucinous appendiceal neoplasms, which are tumors that make a gelatinous material called mucin that can accumulate in the abdominal cavity.
There are other epithelial appendiceal cancers that behave and are treated like the much more common colon cancer, which is not surprising, as the appendix is attached to the colon.
Finally, there are what we call carcinoid tumors or neuroendocrine cancers that occur in multiple places in the body. The appendix is one of the sites these tumors commonly occur.
How is appendix cancer typically diagnosed?
The first sign is often pain. A fraction of patients will present with acute appendicitis, and the cancer is diagnosed when the pathologist evaluates the appendix. A few days after surgery patients may find out they have one of those three different types of tumors. The tumor can be either the cause of the appendicitis, or just an incidental finding.
Another presentation is related to the accumulation of the mucin in the abdominal or peritoneal cavity. The appendix is a pretty thin-walled structure, and as the mucin accumulates and distends the appendix, it can breach the thin wall and spread into the abdomen. Occasionally, the volume of mucin can be several gallons, and this can lead to difficulty eating or even trouble breathing. If patients have a hernia in the groin or at the umbilicus, these can be more noticeable if the mucin accumulates within them.
Are there any specific risk factors for appendix cancer or reasons that people get it?
Some researchers are currently looking at inherited factors, trying to get family histories and look at the genetic makeup of patients with appendiceal cancer, but it isn’t a cancer that appears to be inherited in families commonly. There's also no environmental exposure that seems to predispose people to it. For most of the patients we see, there's no good explanation for it.
Do appendiceal cancer patients tend to be older or younger, or is it all over the board?
For the ones we operate on, the average age tends to be in the mid-50s. We do see younger patients with the disease, even patients in their 20s with different forms of it. The incidence goes up with age, but it certainly can happen in younger patients.
How is appendix cancer treated?
For the slower-growing tumors, if it's confined to the appendix, patients are treated with an appendectomy. If it hasn’t spread anywhere else in the body, there's a low risk it has spread prior to diagnosis and may show up in the future. We follow those patients with a scan once a year for five years.
If it's a true invasive cancer, then we usually recommend doing what's called a right hemicolectomy, or taking out a section of the small and large intestine to get a sampling of regional lymph nodes, which are helpful in determining prognosis. The stage of the cancer is assigned after this surgery and is helpful in deciding whether patients would benefit from chemotherapy in addition to surgery.
If the cancer hasn't spread beyond the appendix, usually that operation is enough. If the cancer is identified in lymph nodes, then patients benefit from three to six months of chemotherapy. If the cancer has spread beyond the appendix and lymph nodes into the abdominal cavity, we do an operation called cytoreductive surgery with heated intraperitoneal chemotherapy, or HIPEC. This procedure can be an extensive operation that removes the cancer from the abdominal cavity and also includes a 100-minute treatment of the abdominal cavity with a heated chemotherapy drug to kill any remaining cancer cells.
What's the function of the appendix?
n adults, nothing. It's a vestigial organ that may have some role early on in development, but there's no clear function for it or reason to have it. Patients do fine when they have their appendix removed.
Are there any signs of appendiceal cancer that people should be aware of? Anything they should get checked out if they experience it?
A lump, an enlarging hernia, new pain — those are all reasons to see your physician in case something new and different is going on. But in some cases, it can be pretty indolent, and what we see on scans can be fairly advanced. Particularly with tumors that grow very slowly, they may have been accumulating in patients for years by the time they bring it to their doctor’s attention. Often there are surprisingly few symptoms until the volume of tumor is very high.