Neuroendocrine tumors (NET) are rare. Neuroendocrine cells are all over your body, so these tumors can originate in several different sites, each of which will have unique biologic features. Carcinoid tumors are the most commonly detected NET and originate from the lungs or gastrointestinal tract.

Causes

The vast majority of neuroendocrine tumors have no established causative link. There is a subset of NET patients where the risk of developing a NET in one or more sites is linked to a genetic disorder. An example of such a genetic syndrome is multiple endocrine neoplasia syndromes, which are associated with cancers in the thyroid, parathyroid, pancreas and adrenal gland. If you have any family members who have experienced cancers in one or more of these locations, you may need to be evaluated for MEN.

Symptoms

Many subtypes of NETs produce hormones that will contribute to profound symptoms that are collectively called a neuroendocrine syndrome. Flushing, diarrhea and palpitations are the most common symptoms. Light headedness, wheezing and blood sugar fluctuations are also established albeit less common symptoms. In many cases, symptoms will overlap with other medical problems. Sometimes, patients will have no symptoms at all.

Diagnosis

A diagnosis of NET is commonly overlooked for years even when patients are going to their medical providers on a regular basis. The tumors are often slow growing, symptoms can be vague, and conventional imaging may not be sensitive enough to pick up small tumors. A biopsy is used to make the diagnosis when a soft tissue mass is recognized.

Cancer Stage

These tumors are staged using the AJCC staging system that evaluates the primary site, involvement of lymph nodes in the area, or any evidence of metastases to other organs. Depending on the location of the primary tumor, other features are used to determine a treatment plan. These include the size and location of the primary, tumor grade, and somatostatin receptor status. All these variables will weigh into treatment recommendations.

Treatment

Treatment recommendations have not been completely standardized for NET and therefore it is important to be evaluated within the context of a multidisciplinary program that includes the entire range of treatment options. Even if this opinion is used to get treatment elsewhere, the recommendations are often individualized based on the unique features of a patient’s case.

In some cases, no treatment is required after the primary tumor is removed. In most cases with metastatic disease, systemic treatment is often recommended. In some cases, chemotherapy is used. 

Medical providers who specialize in NETs, like the team at the Ochsner Neuroendocrine Tumor Program, have an explanation of each treatment option and the type of tumors that are relevant to a certain NET patient. They also have methods through which you can receive a second opinion that will focus on the unique features of your case that drive treatment.

Zebras and NETS

There is a well-known and overused saying in medicine that “If you hear hoofbeats, think of a horse not a zebra,” since most illnesses will fall into one of a handful of “common conditions”. Patients with uncommon medical conditions, like NET, are marginalized within the healthcare system due to the rarity of their disease and the lack of readily available medical providers that are familiar with the diagnosis and treatment of this cancer. 

Neuroendocrine cancers are the “zebras”, making up just 2% of all cancers diagnosed each year in the United States. As such, the zebra has become the symbol for NET not only in the U.S., but worldwide.