What Is It?
Squamous-cell carcinoma of the lung accounts for about 30 percent of cases of non-small-cell lung cancer. Most squamous-cell carcinoma originates in the central portions of the lungs. These tumors may cause symptoms of coughing up blood at an earlier stage than tumors located on the edges of the lungs (such as the more common adenocarcinoma).
Squamous-cell carcinoma often spreads (metastasizes) to other parts of the body because of the constant flow of fluids (blood and lymph) through the lungs. The fluids can carry cancer cells to adjoining structures, such as the chest wall, the neck, esophagus or heart. Unless the cancer is diagnosed and treated early, it frequently becomes a systemwide, rather than local, disease. Outside of the chest, lung cancer commonly spreads to the bones, brain, liver and adrenal glands.
Although some cancers initially have no symptoms, others are diagnosed during an evaluation for any of the following:
- A persistent cough
- Coughing up of blood (hemoptysis)
- Unexplained weight loss or loss of appetite
- Shortness of breath or wheezing
- Increased mucus secretions or phlegm coughed from the lungs
- Difficulty swallowing
- Pain in the chest, shoulder or arm
- Recurrent pneumonias in the same place
- Bone pain
- Headaches, confusion or seizures
- Swelling of the face, neck or upper extremities
- Enlargement of the ends of fingers and toes (digital clubbing)
Squamous-cell carcinoma often is discovered on a chest X-ray, on which it appears as a dark, shaded area. Other imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI), may be used to further determine the size, shape and location of the tumor. This helps to find the best place to obtain a sample of the tumor to diagnose squamous cell versus other types of lung cancer such as small-cell carcinoma or adenocarcinoma of the lung. The type of cancer affects what treatment you should get. The tumor also can spread to the lung from another organ outside of the chest.
Another way to diagnose the tumor type is with sputum cytology, in which mucus from the lungs (sputum) is examined under a microscope to check for abnormal cells. Cancer cells also can be found in fluid between the lung and the chest wall (requiring a thoracentesis procedure using a needle to remove pleural fluid) or in lymph nodes next to the lung (requiring a mediastinoscopy surgical procedure).
Another diagnostic technique is a needle biopsy or fine-needle aspiration, using the guidance of a CT scan. Fluid or tissue can be removed (aspirated) from lymph nodes, a lung mass or from an area of tumor spread in the bone marrow or other organ. Cells also can be removed during bronchoscopy. This is a procedure in which a fiber-optic viewing tube is inserted into the lungs. It allows the doctor to examine the tumor directly and also to remove cells for examination. Occasionally, surgery (thoracotomy) is performed to remove the tumor first and then the diagnosis is made.
Your doctor will choose a therapy based on size and location of the tumor or the presence of cancer cells. Squamous-cell lung cancer is classified by stages defined by size and how far the tumor has spread. Stages I through III are further divided into “A” and “B” categories. Stage I tumors are small and have not invaded the surrounding tissue or organs. Stage II and III tumors have invaded surrounding tissue and/or organs and have spread to lymph nodes. Stage IV tumors have spread outside the chest area.
Without treatment, cancer will continue to grow. As with any cancer, even if squamous-cell lung cancer disappears (goes into remission) after treatment, there is a chance it can come back again.
To prevent squamous-cell lung cancer, quit smoking and avoid secondhand smoke. Tobacco smoke is the main risk factor for most types of lung cancer. Approximately 90 percent of all lung cancers are linked to smoking. Although studies are looking for screening tests to diagnose lung cancer earlier, no test has been proven effective yet.
Surgery is the primary treatment for all non-small-cell lung cancers. Survival rates after surgery vary. For those with stage I disease, the five-year survival rate is about 47 percent. For those with stage III disease, the five-year survival rate is 8 percent. For small, localized tumors, it might be possible to remove only a small section of lung. More extensive carcinoma might require removal of a lobe of a lung or the entire lung. Radiation therapy and chemotherapy (the use of strong medications) may be combined with surgery to help prevent the cancer from recurring.
People with severe medical problems that make it difficult for them to withstand surgery may receive radiation therapy to shrink the tumor or the combination of radiation and chemotherapy.
When there is significant tumor spread, chemotherapy drugs may be recommended to slow the growth of the cancer even if it cannot provide a cure. Chemotherapy has been shown to decrease symptoms and prolong life in advanced cases of lung cancer.
When To Call A Professional
If you experience the symptoms of squamous-cell lung cancer, make an appointment to see your health-care provider.
Squamous cell carcinoma usually is diagnosed after the disease has spread. The overall prognosis for all non-small-cell lung cancers is poor, with a five-year survival rate of about 15 percent. The survival rate is higher (close to 50 percent) when the cancer is detected and treated early.
Even when surgery and other therapies are initially successful, there is a high risk of the cancer coming back. This reflects the fact that squamous-cell carcinoma is rarely restricted to just one area. It readily spreads to other parts of the body.
Diseases and Conditions Center
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.