Although shoulder pain is often caused by physical injury, shoulder pain can actually be a symptom of lung cancer. Shoulder pain may be the first symptom of lung cancer. Unfortunately, there is no way of distinguishing shoulder pain caused by injuries from shoulder pain caused by lung cancer. The shoulder pain is identical or similar to other underlying conditions such as arthritis.
Ways Lung Cancer Can Cause Shoulder Pain
Lung cancer can cause shoulder pain in many different mechanisms:
- Pancoast tumor is a cancer growth in the upper part of the lungs. It can invade certain nerves that supply the arms, shoulders, head, and spine which can lead to severe shoulder pain, weakness in one eyelid, reduced sweating on the affected side of the face, and reduced pupil size in one eye. Pancoast tumor usually causes shoulder pain that radiates down to the arm.B Because of its location, this tumor is less likely to cause usual symptoms of lung cancer like coughing up blood, shortness of breath, and persistent coughing.
- The pain felt in the shoulders can also be a referred pain which means that the pain is felt in the shoulder but the pain is actually from other parts of the body which are most likely close to the shoulders. Shoulder pains happen when the tumor causes pressure on the phrenic nerve that travels near the lungs. The brain interprets this as coming from the shoulder even if the nerve is actually found in the lungs.
- Shoulder pain can also occur due to a tumor in the lungs that spreads or metastasizes to the bones in, near, and around the shoulder and spine. About 30 to 40 percent of patients with lung cancer spread cancer to the bones at some point during the disease. If the tumor in the lung is large, it can press on other structures that are nearby and contribute more pain to the shoulder. This is also known as the mass effect.
- A cancer of the pleura called malignant pleural mesothelioma can also cause shoulder pain. The pleura are the membranes lining the lungs. This disease is mostly caused by exposure to asbestos while on the job. Shoulder pain is usually the first symptom of patients who have mesothelioma.
Shoulder Pain Caused by Lung Cancer
If you recently had a fall or an injury and you are experiencing pain in your shoulder, lung cancer may be ruled out as it is not likely the cause of the pain in your shoulder. Since it is quite tricky to distinguish shoulder pain caused by injuries from shoulder pain caused by lung cancer, it is important to take note of the following factors that may point to lung cancer:
- You are a smoker.
- The shoulder pain occurs while you are resting.
- The pain you are experiencing on your shoulder is not linked with any other strenuous activity that involves the shoulder.
- The pain is not linked to any loss of motion with activity.
- The pain occurs and gets worse at night.
- The shoulder pain doesn’t go away even after a few weeks.
Symptoms of Lung Cancer
To determine if the shoulder pain you are experiencing may be due to lung cancer, aside from shoulder pain, you also experience the other symptoms of lung cancer which include:
- Frequent chest pains
- Shortness of breath which can be mild and only felt with activity
- Sudden loss of weight
- Intense and persistent coughing
- A harsh grating sound with each breath
- Back pain
- Hoarseness in the voice
- Changes in the voice
- Chronic lung problems such as bronchitis and pneumonia
- Coughing up phlegm, mucus, or blood
- A shift in the volume or color of sputum, a mixture of mucus and saliva
- Excess bleeding
- Blood clots
- Bone fractures
- Muscle wasting (cachexia)
- Pain in the joints and bones
- Swelling of the neck and face
- Neurological issues such as poor gait and memory loss
When to See a Doctor?
The chances of lung cancer causing shoulder pain is usually small. If there is no other explanation for the pain that you are feeling on your shoulder, it is necessary to see a doctor. Aside from injuries and a poor posture, shoulder pain may also be a symptom of other underlying conditions.
Other Possible Types of Cancer with Shoulder Pain as a Symptom
Aside from lung cancer which is the more popular type of cancer that causes shoulder pain, there are other types of cancer with shoulder pain as a known symptom.
Primary bone cancer is rare. People who have bone cancer usually have secondary bone cancer which means that cancer in the bones developed as cancer from other body part metastasized to the bones. There are a couple types of bone cancers that affect the shoulders such as osteosarcoma and chondrosarcoma. These types of bone cancers may cause shoulder pain as they affect the shoulders.
Pain or a loss of sensation in the shoulder is one of the symptoms of breast cancer that is recurring. The pain in the shoulder may also be caused by the spreading of the breast cancer to the bones especially since the shoulder is near the breast.