Pancoast tumors are a type of non-small cell cancer that account for less than 5 percent of all lung cancers. They are named after the American radiologist who discovered them in 1932 - Dr. Henry Pancoast.
What are Pancoast tumors?
Pancoast tumors refer to where the cancer is located within the lung space. While most cancers develop lower down in the lungs, Pancoast tumors grow at the top of either lung.
A Pancoast tutor is located at the top of the lungs. The "P" within the image indicates the tumor.
Image credit: Jmarchn.
Due to this positioning they enter adjoining tissue. Commonly affected structures include:
- lymph vessels
- adjacent ribs
- the region located between the lungs
- the small bones of the spine
The risk factors for Pancoast syndrome are similar to those for other lung cancers and include:
- smoking tobacco
- being exposed to secondhand tobacco smoke
- being in long-term contact with asbestos and radon
- being exposed to industrial elements, such as gold and nickel
Although Pancoast syndrome is classically associated with lung cancer, in rare cases it can result from other conditions. These conditions include:
- breast cancer
- desmoid tumors
- adenoid cystic carcinoma
- thyroid cancer
- certain bacterial and fungal infections
The symptoms of Pancoast syndrome differ from the symptoms that accompany cancer in other parts of the lung. In fact, Pancoast tumors rarely cause the coughing or shortness of breath that are typically associated with lung cancer.
Symptoms of Pancoast syndrome may include weakness of the hands and pain in the shoulder and shoulder blade.
Instead, in addition to general cancer symptoms, such as fatigue and weight loss, the Pancoast tumor may cause pressure on nerves in the upper chest, neck, face, and arms. This pressure can lead to specific symptoms such as:
- pain in the shoulder and shoulder blade
- pain in the arm, elbow, or armpit
- weakness of the hand
- pain or tingling in the hand and fingers
The associated pain is severe and constant. Wasting away or shrinking of the hand and arm may also occur.
Horner's syndrome is another type of syndrome associated with Pancoast tumors. It is a combination of signs and symptoms that are caused by damage or disruption to certain nerves.
Horner's syndrome typically affects only one side of the face and can cause:
- a small pupil, leading to an obvious size difference between the pupils of the two eyes
- drooping of the upper eyelid
- elevation of the lower eyelid
- flushing on one side of the face
- lack of sweat on one side of the face
Diagnosis of Pancoast syndrome and Pancoast tumors can be delayed because symptoms are not typical of lung cancer. Frequently, people see a neurologist or orthopedic surgeon before consulting an oncologist.
Pancoast tumors are diagnosed using:
- X-rays: This may reveal abnormal tissue at the top of the lung, and can show if the tumor has invaded the ribs or vertebrae. However, in the early stages Pancoast tumors are difficult to see on an X-ray film due to shadowing.
- CT scan: This can indicate if the tumor has entered the chest wall, spine, blood vessels, nerves, windpipe, food pipe, or region between the lungs.
- MRI: An MRI is generally more accurate than a CT scan at uncovering the extent to which a tumor has invaded other structures. It is often used alongside a CT scan, as the CT may be more effective at examining the region between the lungs.
- Bronchoscopy: This test checks the airways of the lung.
- Tissue biopsy: This involves removing some of the tumor cells for examination. The procedure may be an open chest biopsy, or done using a needle through the skin.
- Other tests: These may be required to check for spread of the cancer to other areas of the body, such as the brain or bones. Examples include an MRI of the brain, bone scans, PET scans, and a mediastinoscopy to check the area between the lungs.
Some combination of X-ray, scan, and biopsy is usually carried out to confirm tumor diagnosis and to accurately assess the stage of the Pancoast tumor.
Based on the TNM (Tumor, Nodes, Metastasis) staging system, Pancoast tumors are always classed as T3 or T4 tumors.
The majority of Pancoast tumors are considered to be T3 tumors because they invade only the chest wall or the chain of nerves that runs from the neck down the spine.
The rest of the Pancoast tumors are considered to be T4 tumors. These tumors invade the spine, nerves running from the neck to upper limbs, or structures made of blood vessels.
When to see a doctor
It is important for people to see a doctor if they develop any of the symptoms of Pancoast syndrome, or any other symptoms associated with lung cancer, such as coughing or shortness of breath.
Pancoast tumors are uncommon and to ensure a swift and accurate diagnosis, people may want to consult a doctor knowledgeable in the area of lung cancer and Pancoast syndrome.
The most effective treatment for a Pancoast tumor may be a combination of chemotherapy, radiation therapy, and surgery.
Treatment of a Pancoast tumor depends on the overall health of the person who has it, the size of the tumor, and the areas it affects. Treatment can aim to reduce symptoms or to remove the cancer.
The main treatments offered are:
The most effective approach is usually one that combines these three treatments. For example, people with early Pancoast syndrome who are in general good health and have limited tumor growth, may receive a combination of radiation and chemotherapy, followed by surgery and post-operative chemotherapy.
Other treatments that may be offered include:
- Targeted therapies: In some cases treatments are available that selectively target cancer cell activity. This causes less damage to healthy cells, and people who have this type of therapy usually experience fewer side effects.
- Symptom relief: Pain medications may help manage symptoms, while steroids can be prescribed to reduce nerve pressure.
Surgery on Pancoast tumors should always be carried out by a specialist surgeon due to the difficulties that can be encountered. Such surgery may involve removal of the entire lung, affected nearby tissues, or the top ribs.
In some situations, removal of a major artery may be required. If so, it will be replaced by an artificial tube to maintain blood supply.
The most important preventive measure that can be taken to reduce the risk of developing any lung cancer is to quit smoking. Avoiding exposure to secondhand smoke and materials, such as asbestos and radon also reduces risk.
Screening is another step that can be taken to catch cancer in its early stages and prevent its progression.
People with a family history of lung cancer, people over 55, smokers, and former smokers may wish to discuss lung cancer screening options with their doctor.
Pancoast tumor survival rates have been rising over the last few decades, and they now have a better outlook than cancerous tumors located lower down in the lungs.
After treatment with chemotherapy, radiation, and surgery, the 2-year survival rate is 55-70 percent. The 5-year survival rate for those whose surgery allows complete removal of cancerous cells is 54-77 percent. Survival is better for T3 than T4 stage tumors.
Surgery for Pancoast tumors is associated with a 5 percent mortality rate while the complication rate is 7-30 percent.
The main factors associated with a poorer outlook in those who undergo treatment are the presence of Horner's syndrome and incomplete removal of the tumor cells.