Neuroendocrine tumors in the lungs require a team that knows what to do — not only for diagnosis, but also for treatment planning. The Penn Neuroendocrine Tumor Program has experience with all forms of these rare tumors, to help with whatever you need.
When tumor removal is possible, our surgeons look to spare lung tissue. And when you need more, we offer a range of options, including some not widely available. We carefully consider all recommendations — we care about your life back home, not just the disease in front of us.
What Is a Lung Neuroendocrine Tumor?
Neuroendocrine tumors (NETs) are a rare type of pulmonary neoplasm (growth) that represents less than two percent of all lung tumors.
Among the types of neuroendocrine tumors, though, 20 percent to 30 percent start in lung or airway tissue. Those airways include the trachea (windpipe), the bronchi (running from the windpipe to lungs) and bronchioles (smallest branches).
It appears cases of these uncommon tumors are on the rise, though doctors and scientists aren't sure why.
Many lung NETs are benign (noncancerous) and removable with surgery. But for more than a quarter of people diagnosed, the disease has grown into nearby tissue or metastasized (spread farther). The likelihood that a lung NET will spread depends on the kind of tumor. Doctors classify types of lung NETs based on how cells look under a microscope:
Lung Carcinoid Tumors
Cells in lung carcinoid tumors look more or less like normal cells. Doctors call this "well-differentiated". They break lung carcinoids into two groups, based on further appearance and how tumors act and respond to treatment:
- Typical carcinoids: Cells in these tumors look the most normal. These tumors, often located in the center of the lungs or the windpipe, typically grow slowly and usually don't spread beyond nearby lymph nodes. Because of their slow-growing nature, they don't respond as well to chemotherapy or radiation therapy.
- Atypical carcinoids: These tumors, often found at the outer lung edges, may show signs of necrosis (cell death) and mitosis (greater cell division). Some grow slowly like typical carcinoids, while others act more aggressively. At diagnosis, up to 50 percent of atypical carcinoids have spread to the lymph nodes in the chest. They may also metastasize to the bones (most frequently) and liver. Still, they remain highly treatable and spread more slowly than other, more common lung cancers.
Neuroendocrine Lung Cancers
Neuroendocrine lung cancer cells look poorly differentiated — very unusual compared to normal cells, with possible loss of structure. These cancers behave more aggressively and can spread to the brain (most commonly), liver, bones and adrenal glands. They include:
- Form of small cell lung carcinoma (SCLC)
- Cancer called large cell neuroendocrine carcinoma (LCNEC)
Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH)
Occasionally, neuroendocrine cells in the lungs' small airways become overactive and grow a little more than they should. Very rarely, these cells eventually form a carcinoid. More often, the cells don't form a tumor but can cause asthma-like symptoms.
DIPNECH may appear on a scan given for another reason or because of symptoms. If asthma treatments don't provide relief, we may recommend hormone-related medications used for lung NETs.
Lung NET Risk Factors and Genetics
We often don't know why someone develops a neuroendocrine lung tumor. But scientists have identified a few risk factors, such as long-term smoking and asbestos exposure.
Very rarely, people inherit a particular genetic mutation, or variant, tied to lung NETs. About 5 percent of people with the genetic condition MEN1 develop a lung NET. MEN1 can also lead to tumors in the parathyroid gland, pituitary gland and pancreas.
Learn more about our genetic testing for neuroendocrine tumors and genetic counseling services.
Classic Symptoms of a Lung Neuroendocrine Tumor
Neuroendocrine lung tumors may not cause symptoms until they grow larger or spread. When they do occur, many symptoms are asthma-like. They include:
- Cough that you can't get rid of, though it may vary in intensity throughout the day
- Coughing up small amounts of blood
- Fatigue
- Frequent chest infections (such as pneumonia), or an infection that resists treatment
- Pain in the chest or shoulders
- Shortness of breath
Lung NET Symptoms Tied to Hormones
Some neuroendocrine tumors release hormones, which can cause their own sets of symptoms. While only 10 percent of lung NETs cause this complication, it’s still something doctors need to watch carefully.
Most hormone spikes from a lung NET involve adrenocorticotropic hormone (ACTH). High ACTH can cause a condition called Cushing's syndrome, marked by high blood pressure, low potassium and weight gain. We watch for these symptoms and treat them as needed.
Less frequently, people with a lung NET experience carcinoid syndrome, from the tumor releasing serotonin or related hormones. They may experience diarrhea, wheezing and flushing (temporary redness in the face.) Our gastrointestinal symptom management for endocrine tumors can help.
Diagnosing Small Lung NETs
Many lung NETs get discovered through a chest X-ray or CT for symptoms tied to the lungs, cancer screening or other medical reasons. These scans can show nodules (small, unusual growths). Doctors may watch a nodule at first to see if it grows; not all nodules are cancerous.
If a nodule is suspicious, doctors will perform a biopsy to determine what it is. For nodules that are reachable through the windpipe or blocking the windpipe, doctors use a bronchoscope (camera and thin tube) to access the growth. Deeper in the lung, they may take a tissue sample (biopsy) with a needle or remove the nodule entirely with surgery.
Generally, lab analysis can reveal if the growth is a tumor and, if so, what kind. For lung carcinoids, pathologists try to tell if the tumor is typical or atypical.
Lung NET Evaluation at Penn
Not all lung NETs get diagnosed when they're small or slow growing. At Penn, our team has experience evaluating the full range of cases. We offer:
- Standard imaging: In addition to bronchoscopy and CT, lung function tests can signal a possible lung NET. Our team may also use MRI to confirm a lung NET diagnosis and determine the extent of the disease.
- Hormone testing: We run blood and urine tests to look for signs of hormone release related to lung NETs.
- Review of previous evidence: If a tumor has already been biopsied elsewhere, our specialized pathologists review the results, providing the best chance at accurate interpretation. They can often determine whether a carcinoid is typical or atypical. But even if they can't give that definitive label, our team knows to watch for other clues.
- Possible biopsy: Biopsy can come with some risks, so we weigh the benefits and possible downsides before we perform one. Some tumors may also prove hard to reach for biopsy. If we don't have a biopsy to determine tumor type, our expert tumor board uses other clues to plan care.
- Functional imaging: Other tools include imaging with nuclear medicine, a newer approach. A small, injectable dose of radioactive material binds to various substances taken in by tumor cells. This type of imaging can distinguish between carcinoids and poorly differentiated tumors. It can also show how far the disease may have spread and what treatment may work.
Why Choose the Abramson Cancer Center for Lung Neuroendocrine Tumors?
At the Penn Neuroendocrine Tumor Program, we have deep experience with lung NETs and their unique challenges. We're able to offer you as many options available: whatever you need, whether that's an initial evaluation, a second opinion or further treatment.
When you come to our Neuroendocrine Tumor Program, you'll find:
- Expertise: Specialists across our teams are used to working with lung NETS. For example, our pathologist focuses solely on lung NETs and other lung tumors. This background helps when determining the type of lung NET. Meet our neuroendocrine tumor team.
- Collaboration: When cases require more involved treatment, teamwork plays a key role for timing and therapy choice. Many of our providers regularly attend the weekly neuroendocrine tumor board. They're joined as needed by lung specialists including thoracic oncologists, thoracic surgeons and pulmonologists. Cases may also go to the lung tumor board.
- Options: Sophisticated surgeries at Penn can preserve more lung tissue, protecting lung function. Our surgeons also consider minimally invasive approaches when possible. For disease that has grown or spread, we offer options not widely available, including nuclear medicine for lung carcinoids.
- Support: From the moment you contact us, our nurse navigator helps answer your questions, schedule your appointments and attend to your other needs. We make your experience as easy and stress-free as possible. Once your care starts, we offer a range of additional support for neuroendocrine tumors.
Our Approach to Treating Neuroendocrine Lung Cancer and Tumors
We create personalized treatment recommendations, based on a thorough review by our neuroendocrine tumor board. We consider:
- Type of tumor
- Its size and location
- How fast it's growing
- Whether it's spread, and how extensively
- Your symptoms
- Your preferences and overall health
Removing Lung NETs With Surgery
Whenever possible, our surgeons remove lung NETs with a variety of neuroendocrine tumor surgery options. We have the expertise to remove many lung carcinoids, as well as some early-stage, poorly differentiated tumors. Removing the tumor relieves symptoms and can provide a cure.
Our surgeons take a minimally invasive approach to surgery when possible. They also look to preserve lung function by removing as little lung tissue as necessary to remove the tumor. They may also need to remove nearby lymph nodes. For poorly differentiated tumors, we may follow up with chemotherapy, radiation therapy or both to destroy any remaining cancer cells.
Other Lung NET Therapies
Our surgeons can't always fully remove lung NETs that have grown too big or spread too far. Some people also can't undergo surgery or choose not to.
In such cases, our team identifies other therapies that may manage the disease and provide symptom relief. They work with you to determine what's most important to protect your health and quality of life. Many people — especially those with lung carcinoids — can live years by trying various treatments, often with breaks between options.
Therapies include:
- Debulking: Even for large or extensive tumors, surgery can help by removing some of the primary tumor, metastatic spots or both.
- Observation: If the lung NET grows slowly and doesn't cause problems, we may suggest watching it until the situation changes, with scans every few months.
- Drug therapy: Some carcinoids respond to medications modeled after hormones. Newer drugs called targeted therapies interfere with the paths carcinoids rely on for growth. And chemotherapy may stop cancer from expanding, particularly for poorly differentiated cancer. Learn more about drug therapy for neuroendocrine tumors.
- Nuclear medicine: Special molecules can potentially deliver radiation into carcinoid cells found anywhere in the body. Learn more about nuclear medicine for neuroendocrine tumors.
- Liver treatment: If the disease spreads to the liver, a range of treatments can relieve symptoms and protect liver health. Learn more about liver-directed therapy for neuroendocrine tumors.
- Radiation therapy: Radiation delivered by a machine outside the body can target the original tumor or metastatic spots to stop growth.
- Clinical trials: We may have a clinical trial that meets your needs. Recent trials include an effort to pair targeted therapy with immunotherapy, which harnesses the immune system. Learn more about our neuroendocrine research and clinical trials.
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To make an appointment, please call 800-789-7366 or request a callback.