Neuroendocrine Tumors

Neuroendocrine tumors are a diverse group of cancers that develop from neuroendocrine cells, which have traits of both nerve cells and hormone-producing cells. These cells are found throughout the body, especially in organs such as the gastrointestinal tract, pancreas, and lungs. Neuroendocrine tumors may grow slowly or aggressively and can be functional, producing excess hormones, or nonfunctional, producing no hormones but still causing symptoms due to tumor growth.

Symptoms

Symptoms of neuroendocrine tumors vary depending on tumor location and whether hormones are produced:

• Abdominal pain or discomfort

• Diarrhea or changes in bowel habits

• Flushing of the skin

• Wheezing or shortness of breath

• Unexplained weight loss

• Fatigue

• Heart palpitations

Hormone-producing tumors may cause specific syndromes related to excess hormone release.

Causes

The exact cause of neuroendocrine tumors is not fully understood. They occur when neuroendocrine cells develop genetic mutations that cause uncontrolled growth. Most cases arise sporadically, but some are linked to inherited genetic syndromes. Environmental and lifestyle factors may contribute, although clear associations are not always identified.

Risk Factors

Several factors may increase the risk of developing neuroendocrine tumors:

• Family history of inherited genetic syndromes such as multiple endocrine neoplasia

• Chronic gastrointestinal conditions

• Older age

• Smoking, particularly for lung neuroendocrine tumors

• Certain genetic mutations

Risk varies based on tumor type and location.

Complications

Neuroendocrine tumors can lead to complications related to hormone excess or tumor spread:

• Hormonal imbalances causing flushing, diarrhea, or blood sugar changes

• Metastasis to the liver, bones, or other organs

• Heart valve damage in hormone-secreting tumors

• Intestinal obstruction or bleeding

• Side effects from surgery, chemotherapy, or radiation therapy

Early diagnosis helps reduce the risk of severe complications.

Prevention

There is no proven way to prevent neuroendocrine tumors, but risk reduction strategies may be beneficial:

• Genetic counseling and screening for individuals with a family history

• Avoiding tobacco use

• Managing chronic health conditions

• Seeking medical evaluation for persistent, unexplained symptoms

Regular monitoring and timely medical care are essential for improving outcomes in people with neuroendocrine tumors.