What Is a Pancoast Tumor?

Pancoast tumors are a type of lung cancer that invades the chest wall. They are sometimes called superior sulcus tumors and defined by their location in the upper part (apex) of the lung. They often invade nerves and other structures nearby, sometimes spreading to the brain.

Pancoast tumor symptoms include arm and shoulder pain, and tingling and weakness in the hands. Symptoms can mimic those of bone and joint diseases, and these tumors can be difficult to spot on X-rays. They account for just 3% to 5% of lung cancers, but their diagnosis is often delayed until late stages.

This article discusses pancoast tumors, their causes, and how they are diagnosed and treated.

Types of Pancoast Tumors

Most pancoast tumors are a form of non-small cell lung cancer. The most common types are:

• Squamous cell carcinoma at 52%
• Adenocarcinomas at 23%
• Large cell carcinomas at 20%

Only about 5% of Pancoast tumors arise from small cell lung cancer.

Pancoast Tumor Symptoms

Pancoast tumor symptoms are caused by the compression of nerves and other structures that lie near the upper part of the lung where the cancer is present. The tumor is associated with a unique set of symptoms known as Pancoast syndrome, sometimes called Pancoast-Tobias syndrome.

Pancoast syndrome creates a constellation of symptoms that, taken together, help to inform a diagnosis.

Arm and Shoulder Pain

Pain in the shoulder is the most common early symptom of a Pancoast tumor. Pain frequently radiates down the arm (especially on the inside of the arm and on the pinky side of the hand) and is often severe and unrelenting. Pain can also radiate into the armpit or shoulder blade.

Weakness in Hand Muscles

People may feel weakness in the muscles of the hand. This weakness can easily be dismissed or misdiagnosed as a musculoskeletal condition of the joints and muscles.

Tingling or Numbness in the Hand

Tingling or numbness is especially common in the ring and pinky fingers. In some cases, people also experience swelling in the hand.

Horner's Syndrome

Horner's syndrome is a collection of symptoms that occur only on one side of the face.

These include:

• Drooping upper eyelid
• Diminished or complete absence of sweating
• Inward sinking of the eyeball
• Smallness or excessive constriction of the pupil of the eye

Swelling of the Arm or Neck

Sometimes there is also swelling of the upper arm due to pressure on the subclavian vein, which runs beneath the collarbone. People with Pancoast syndrome also may experience swelling in the neck area, with difficulty swallowing or changes in their speech patterns.

Headache

Pancoast tumors are not typically associated with headaches but they may arise in rare cases, as a complication of treatment, or because the cancer has spread to the brain.

Causes

Smoking is a primary risk factor in lung cancers, and cases have decreased overall due to declining numbers of people who smoke. However, it's important to note that the diagnosis of lung cancer is growing in non-smokers (either former smokers or those who have never smoked, and especially in young women).

Other risk factors for lung cancer include radon exposure, secondhand smoke, and occupational exposures to chemicals and substances known to cause lung cancer.

Diagnosis

The average age of Pancoast tumor diagnosis is around 60 years, and men are more frequently affected than women.

Diagnosis of Pancoast tumors is frequently delayed. One reason is that these tumors are less likely to produce typical lung cancer symptoms (such as shortness of breath and coughing), so symptoms may be mistaken for a neurological or orthopedic condition.

Pancoast tumors are also difficult to see on chest X-rays due to their location. As a result, once these tumors are accurately diagnosed, they are usually at an advanced stage.

A combination of computed tomography (CT) and magnetic resonance imaging (MRI) scans is often used in the diagnosis of Pancoast tumors. An MRI is important before surgery to look for nerve involvement.

A lung biopsy—whether an open chest biopsy (thoracotomy) or a biopsy of the lymph nodes above the collarbone (supraclavicular lymph node biopsy)—is often done to confirm the diagnosis. Other tests, such as a bronchoscopy to visualize the airway, may be done as well.

Staging

Pancoast tumors are staged similarly to other lung cancers, by using Roman numerals I to IV and the subtypes A or B to indicate the progression of the disease. Many of these cancers are stage IIB non-small cell lung cancer.

Based on TNM lung cancer staging, most of them are T3 or T4. This means that the tumor is often larger than 7 centimeters (or 3.5 inches) in diameter at the time of diagnosis.

Staging is often done with a combination positron emission tomography PET scan/CT.

Differential Diagnosis

While Pancoast tumor symptoms are most often associated with lung cancer, they sometimes occur with other conditions. These conditions may include:

• Other types of cancers
• Bacterial or fungal infections
• Diseases like tuberculosis

Pancoast Tumor Treatment

Treatment options for people with Pancoast tumors depend upon the extent of the tumor. Currently, the preferred treatment includes a combination of chemotherapy and radiation therapy followed by surgery.

Chemotherapy

Pancoast tumor treatment usually begins with lung cancer chemotherapy, whether or not surgery is possible immediately.

Due to the location of this type of tumor, which can make surgery difficult, the goal is to reduce its size as much as possible before surgery. This chemotherapy treatment before surgery is called "induction therapy."

Targeted Therapies

Many Pancoast tumors have targetable mutations. These are genetic abnormalities found through gene testing for which targeted therapies are available. Targeted therapies are a form of precision medicine that are selected based on precise information about your specific disease.

Since several targeted therapies are now available for treating lung adenocarcinoma and squamous cell carcinoma, it is very important to have genetic testing (molecular profiling) done.

Targeted therapy medications are currently approved for people who have a number of mutation types, including:

• EGFR mutations
• ALK rearrangements
• ROS1 rearrangements
• BRAF mutations

Additional treatments are under development and being studied in clinical trials.

Surgery

Surgery can often be done on Pancoast tumors. It is usually performed after chemotherapy and/or targeted therapy plus radiation therapy to shrink the size of tumors. Because this surgery can be challenging, it's important to find an experienced surgeon familiar with this condition.

Surgery for Pancoast tumors has generally been done via a thoracotomy, an open chest surgery in which a rib is separated or removed.

However, a 2014 study suggested that minimally invasive surgery with video-assisted thoracoscopic surgery (VATS) may be safe and effective. VATS involves making small incisions in the chest and using instruments to remove a tumor.

Since Pancoast tumors are often located close to nerves, it's recommended that both a thoracic surgeon and a neurosurgeon be present for these surgeries. During surgery, lymph nodes in the chest between the lungs, called mediastinal lymph nodes, are often removed as well.

Radiation Therapy

If a cure is not considered possible, radiation therapy can still be helpful as palliative therapy to relieve pain and alleviate other symptoms. Radiation therapy may also be used along with chemotherapy to shrink a tumor before surgery.

Immunotherapy

Immunotherapy is a possible treatment for some non-small cell lung cancers. This treatment uses your body's own immune system to attack cancer.

Checkpoint proteins on immune cells are normally activated to start an immune response. Cancer cells can deactivate these checkpoints to avoid being attacked by the immune system. Drugs that target these proteins are called checkpoint inhibitors, and they allow the immune system to attack cancer.

Some immunotherapy drugs approved to treat Pancoast tumors include:

• Opdivo (nivolumab)
• Keytruda (pembrolizumab)
• Tecentriq (atezolizumab)
• Imfinzi (durvalumab)

Libtayo (cemiplimab) is also approved for the treatment of some people who have Pancoast tumors, depending on the expression of the protein PD-L1.

Imflinzi is also approved, in combination with Imjudo (tremelimumab) and platinum chemotherapy, to treat certain advanced metastatic non-small cell lung cancer.

Physical Therapy

Physical therapy may be a component of treatment to maintain upper body function and quality of life in people who have surgery and other treatments for Pancoast tumors.

This may be increasingly important as Pancoast tumor treatments extend survival times, and people live longer with significant impacts to structures affected by the tumor and treatment, such as arm and muscle function.

Prognosis

Survival rates for Pancoast tumors have been improving, and they depend on the stage of the tumor at the time of diagnosis, whether it has metastasized to lymph nodes or other organs, and the effects of treatment.

For people who have surgically treatable cancer, the five-year survival rate is generally considered to be between 30% and 50%, although higher rates have been reported.

The five-year survival rate tends to be lower in people who have late-stage inoperable tumors that have invaded the lymph nodes.

A Word From Verywell

Being diagnosed with cancer can be difficult. Seeking out a support group or a mental health counselor can help you cope with your fears and emotions and help you feel less alone. Your healthcare provider can help you find a therapist and/or group specifically geared to cancer patients, as can organizations like the American Cancer Society (ACS).