Dental considerations of neuroendocrine tumors and carcinoid cancer . . . really?

If you made it past the title, perhaps you’ve heard of this rare cancer. Otherwise, you’re just curious. I was introduced to this cancer when, 10 years ago, my husband received the kind of diagnosis that no one ever wants to hear: “You have cancer in the pancreas and too many tumors in the liver to count.”

The diagnosis disrupted our otherwise ordinary lives. However, subsequent biopsies discovered that the cancer in the pancreas wasn’t a highly aggressive adenocarcinoma, which is the common type. Instead, my husband had what are known as neuroendocrine tumors, which had metastasized from the pancreas to the liver. This rare condition is sometimes referred to as carcinoid cancer.

Although neuroendocrine tumors are rare, carcinoid is the most common of them. Carcinoid cancer can originate in the pancreas, but it can also start in the intestinal tract, lungs, and rectum. In fact, it can begin in almost any organ because it develops in neuroendocrine cells, which are located throughout the body and produce chemicals (hormones, etc.) that help regulate body functions. The most common age of diagnosis for neuroendocrine tumors is the fifth decade of life. It can affect children, and there are types that have a familial link. The causes of most neuroendocrine tumors are unknown.

Treatments ‘reset the clock’

Generally speaking, neuroendocrine tumors are slow-growing cancers. These quirky malignancies have a variety of notable features. For example, they can ramp up in aggressiveness and metastisize the longer they are in the body. Or, they may become stable and not grow or spread for years. There is typically no rhyme or reason to the long-term progression. Additionally, neuroendocrine tumors are resilient. Patients have been informed by doctors following surgery, “We got it all,” only to have the cancer resurface months or years later. This happens irrespective of the chemotherapeutic agent, radioactive agent, or other treatment used to eliminate it.

Treatments are designed to “reset the clock” and slow tumor growth. However, no two patients are alike with these cancers, so treatment that proves effective in slowing tumor growth with one person may have zero effect on another. Best outcomes are achieved when neuroendocrine tumor patients seek care from physicians who have devoted their careers to researching and treating these atypical diseases.

Because neuroendocrine cancers are uncommon, accurate diagnosis is often overlooked—for years. As a result, the majority of patients diagnosed with neuroendocrine tumors are in Stage IV, with metastasis to nearby or distant organs. Frequently, patients are misdiagnosed with irritable bowel syndrome (due to digestive issues) or asthma (when there are breathing issues and the lungs are involved). Some female patients have been reassured that their symptoms are simply postmenopausal.

Patients with neuroendocrine tumors often experience the release of excess hormones and histamines in the body, which contributes to the classic symptoms of diarrhea, wheezing, flushing, fatigue, and abdominal pain. Some patients will experience right-sided valvular heart disease with a thickening of the endocardium, which leads to the need for heart valve replacement. Other patients live with the disease while it spreads silently, and these patients experience few symptoms for years.

Interestingly, the zebra has been adopted as the icon for neuroendocrine tumors. Zebras are a reminder to phyicians searching for accurate diagnoses that “not all hooves are horses,” as the medical saying goes. It reminds them to look for an uncommon cause of otherwise common symptoms.

Considerations for dental patients

A concern for neuroendocrine patients—one that dental professionals may not be aware of—is the contraindication for use of anesthetics containing epinephrine. This is because epinephrine releases significant amounts of serotonin, a hormone that often is produced in excess among carcinoid patients. Additional epinephrine can lead to a condition called carcinoid crisis, which is characterized by profound flushing, bronchospasm, tachycardia, and widely fluctuating blood pressure.1 When neuroendocrine patients need to undergo oral surgery involving general anesthesia, they usually require an IV drip of a medication called Sandostatin. The medication helps them avoid carcinoid crisis, which develops under the stressors of surgery that is coupled with general anesthesia. Precautions surrounding anesthesia are imperative: if not identified or properly treated, carcinoid crisis can be fatal.

Some neuroendocrine patients will experience cancer that metastisizes to the bones, in which case they likely have been prescribed bisphosphonate therapy. This therapy increases the risk for osteonecrosis of the jaw. A common chemotherapeutic agent prescribed to neuroendocrine patients is Everolimus, also known as Afinitor. Initial dosing of this drug creates significant oral ulcerations as a side effect, and it is not only extremely painful, but may interfere with routine oral care and nutritional intake. A careful review of a patient’s medical history will reveal if the patient has previously or is currently on these medications.

Also, don’t be surprised if neuroendocrine patients resist routine dental x-rays. The scans that are necessary to diagnose and monitor the disease, as well as some of the more common treatments, involve high doses of radioactive infusions. Because many neuroendocrine patients can live for years with this disease while undergoing numerous radioactive exposures, concern over cumulative radiation is valid. This is not to say dental x-rays should be avoided, but rather taken with discretion.

Final thoughts

In your entire career, you may only treat a few patients with neuroendocrine tumors, but increasing your knowledge of this unusual cancer gives you an advantage to make the dental experience a positive one.

How’s my favorite neuroendocrine patient doing? We recently returned from Germany, where he received a second radioactive nuclear treatment that appears to be doing exactly what we hoped—shrinking tumors, which resets the clock again!

Reference

1. Powell B, Al Mukhtar A, Mills GH. Carcinoid: the disease and its implications for anaesthesia, Cont Ed Anaesth Crit Care Pain. 2011;11(1):9-13.

Author’s note

For those interested in learning more about neuroendocrine tumors, visit carcinoid.org.

Karen Davis, BSDH, RDH, is the founder of Cutting Edge Concepts, an international continuing education company, and practices dental hygiene in Dallas, Texas. She is an independent consultant to the Philips Corp., Periosciences, and Hu-Friedy/EMS. She can be reached at
[email protected].