A Pancoast tumor is a rare form of lung cancer. This type of tumor is located at the very top (apex) of the right or left lung. As the tumor grows, its location enables it to invade surrounding nerves, muscles, lymph nodes, connective tissue, upper ribs, and upper vertebrae. This causes severe pain in the shoulder and arm.
Diagnosis of Pancoast tumors is often delayed, because the tumor doesn’t show the classic symptoms of lung cancer, such as a cough.
Pancoast tumors are also known as superior sulcus tumors. Their particular set of symptoms is called the Pancoast syndrome. The average age of individuals with tumor onset is around 60 years old. Men are more frequently affected than women.
This cancer is named after Henry K. Pancoast, a Philadelphia radiologist who first described the tumors in 1924 and 1932.
The cancer cell subtypes of Pancoast tumors are:
- squamous cell cancer
- large-cell carcinomas
- small cell carcinomas
Sharp shoulder pain is most common symptom of Pancoast tumor in its early stages. Other symptoms depend on the areas the tumor invades around the chest opening (thoracic inlet).
As the tumor grows, the shoulder pain gets more severe and debilitating. It can radiate toward the armpit (axilla), the shoulder blade, and the bone that connects the shoulder to the arm (scapula).
In more than two-thirds of Pancoast tumor cases, the tumor invades the rear and middle compartments of the chest opening. The pain can radiate:
- down the arm on the side of the body following the ulnar nerve (the nerve that runs down the side of your arm toward the pinky, stopping at the wrist)
- to the neck
- to the upper ribs
- to the nerve network that reaches to the ribs, spinal cord, and armpit
Other symptoms include:
- upper arm swelling
- weakness in the hand muscles
- loss of hand dexterity
- wasting of muscle tissue in the hand
- tingling or numbness in the hand
- chest tightness
- weight loss
Altogether these symptoms are known as the Pancoast syndrome.
In 14 to 50 percent of people with Pancoast tumors, the cancer invades the nerves that reach up into the face. This is called the Claude-Bernard-Horner syndrome, or simply the Horner’s syndrome. On the affected side, you may have:
- a droopy eyelid (blepharoptosis)
- inability to sweat normally (anhidrosis)
- displacement of your eyeball (enophthalmos)
The pain of a Pancoast tumor is severe and constant. It usually doesn’t respond to common over-the-counter pain relievers. The pain remains whether you’re sitting, standing, or lying down.
The causes of a Pancoast tumor are similar to those of other lung cancers. These include:
- exposure to secondary smoke
- long-term exposure to heavy metals, chemicals, or diesel exhaust
- long-term exposure to asbestos or high levels of radon
Diagnosis of a Pancoast tumor is challenging and often delayed because its symptoms are similar to those of bone and joint diseases. Also, Pancoast tumors are rare and may be unfamiliar to doctors. Pancoast tumors make up only 3 to 5 percent of all lung cancers.
Your doctor will ask you about your symptoms, when they began, and if they’ve changed over time. They’ll conduct a physical exam and order tests to look for a tumor and any spread of the cancer. If a tumor is detected, your doctor may order additional tests to determine the stage of the tumor.
Tests may include:
- X-rays. Sometimes the tumor may be difficult to detect on an X-ray because of its position.
- CT scan. Its higher resolution can identify the spread of the tumor to nearby areas.
- MRI scan. This imaging test can show the tumor’s spread and provide a guide for surgery.
- Mediastinoscopy. A tube inserted through the neck allows a doctor to take a sample of lymph nodes.
- Biopsy. Removing tumor tissue for examination is considered necessary to confirm the tumor stage and determine therapy.
- Video-assisted thoracoscopy (VATS). This minimally invasive surgery allows access to tissue for analysis.
- Mini-thoracotomy. This procedure uses small incisions, also to access tissue for analysis.
- Other scans. These may be needed to check for the spread of the cancer to bones, the brain, and other areas of the body.
Although once considered fatal, today Pancoast tumors are treatable, though not yet curable.
Treatment for a Pancoast tumor depends on how early it’s diagnosed, how far it has spread, the areas involved, and your general state of health.
A Pancoast tumor is “staged” in a similar way to other lung cancers, using roman numerals I to IV and subtypes A or B to indicate how advanced the disease is. The staging is a guide for the specific treatment you’ll receive.
In addition, Pancoast tumors are further classified with letters and numbers 1 to 4 that indicate the severity:
- T designates the size and spread of the tumor.
- N describes the lymph node involvement.
- M refers to whether distant sites have been invaded (metastases).
Most Pancoast tumors are classified as T3 or T4, because of their location. The tumors are classified as T3 if they invade the chest wall or the sympathetic nerves. They are T4 tumors if they invade other structures, such as the vertebrae or brachial nerves.
Even the earliest detected Pancoast tumors are staged as at least IIB, again because of their location.
Treatment for Pancoast tumors is varied and involves a combination of chemotherapy, radiation, and surgery.
Pancoast tumors that have metastasized to areas beyond the chest may not be candidates for surgery.
Chemotherapy and radiation are the first steps before surgery. Then the tumor is reevaluated with another CT scan or other imaging test. Surgery ideally takes place three to six weeks after chemotherapy and radiation, before any scarring might get in the way of surgery.
In some treatment plans, surgery may be followed by additional radiation treatments to kill any remaining cancer cells.
The goal of surgery is to completely remove the cancerous material from the structures it has invaded. This isn’t always possible, and the disease may recur. A small study done in Maryland found that the disease recurred in 50 percent of those participants who had Pancoast tumor surgery.
Technical advances in surgical techniques have made it possible to perform surgery on T4 Pancoast tumors, but the outlook is worse than for other stages of the disease.
Pain relief for Pancoast tumors today involves a controlled use of opioids prescribed by a doctor. However, this comes with undesirable side effects. Some researchers have argued for a return to pre-opioid measures that are effective without side effects.
Radiation may also be used to relieve pain when surgery isn’t possible.
Severe pain with Pancoast tumors can be eased with a surgical procedure that disables the pain-conducting nerves in the spinal cord. This is called a CT-guided cordotomy, in which a CT scan is used to guide the surgeon.
In one study, 98 percent of those with Pancoast tumor reported significant pain improvement with this procedure. A cordotomy even in the last weeks of life may provide pain relief.
Other possible interventions to ease Pancoast tumor pain include:
- decompression laminectomy (surgery that removes pressure on the spinal nerves)
- phenol block (injecting phenol to block nerves)
- transdermal stimulation (using low-level direct electric current on the brain)
- stellate ganglion block (injecting anesthetic into the nerves in the neck)
Survival rates after chemotherapy, radiation, and surgery vary. A Cleveland Clinic report noted the overall two-year survival rate after surgery as 55 to 70 percent. The 5-year survival rate for surgeries that removed the original Pancoast tumor completely was 54 percent to 77 percent.
For many years, Pancoast tumors were considered untreatable. Because of the tumor location, it was thought that surgery wasn’t possible.
In recent decades, the outlook for people with Pancoast tumors has greatly improved. New surgical techniques have made it possible to operate on tumors that were previously considered inoperable. The now-standard treatment involving chemotherapy, radiation, and surgery has increased survival rates.
Early detection of a Pancoast tumor is important in determining the success of treatment. See your doctor right away if you have symptoms, and take preventative measures such as quitting smoking if you smoke.