Pancoast-Tobias cancer represents approximately 3 to 5% of lung tumors. Its particularity? It does not develop in the center of the lungs, but at the very top, at the apex, their top. At this location, it does not immediately disrupt breathing, but compresses nerves essential to the mobility of your upper limbs.
Why does your arm alert you to your lungs?
Anatomical proximity is the key to this diagnosis. The top of the lung almost touches the base of the neck, where the “brachial plexus”, a network of nerves that controls the shoulder, arm and hand, passes.
“This tumor grows at the lung apex and invades the brachial plexus nerves that control the arm, causing burning pain in the shoulder, radiating to the arm and hand” warns Dr. Gérald Kierzek.
This pain is not mechanical (like a stiffness), but neurological. It manifests itself by:
- Electrical burning sensations;
- Muscle weakness in the arm;
- Numbness or tingling down to the fingertips.
“Horner syndrome”: the facial sign to watch out for
Sometimes the warning signal is not just in the arm, but on the face. As the tumor progresses, it can affect the sympathetic nerves in the area. This is called the
Claude Bernard-Horner syndrome.
It can be recognized by three signs on one side of the face: an eyelid that droops slightly, one pupil smaller than the other and a face that remains dry (absence of perspiration).
If you experience shoulder pain associated with any of these eye changes, the pulmonary origin is strongly suspected.
When shoulder pain becomes a medical emergency
The trap is to treat this cancer as a simple tendonitis or osteoarthritis problem. For Dr. Kierzek, the persistence of pain is the major criterion. “You should consult immediately if unexplained shoulder or arm pain persists, without sport or fall, especially with weakness or Horner’s signs.
A simple chest x-ray or CT scan will then allow the doctor to check the condition of the top of the lung and remove any doubt. The earlier treatment is received, the greater the chances of preserving arm mobility.
Treatments: a combined attack strategy
The treatment of Pancoast-Tobias is specific. It usually begins with a combination of chemotherapy and radiotherapy to reduce the tumor mass, followed, if possible, by surgery. “The prognosis is better if diagnosis is early, with a 5-year survival of around 50%.recalls the expert, while emphasizing the crucial contribution of immunotherapy in recent years.
On the other hand, the surgical intervention can be cumbersome because it involves removing the tumor but also, sometimes, pieces of ribs or nerves already invaded. This is why detection at the first moment of arm pain is essential.
In short, shoulder pain that goes down the arm is not always linked to physical exertion. If it is accompanied by weakness or change in the eye, do not waste time. A lung test could save your life.