Squamous cell carcinoma — also known as epidermoid carcinoma — is a subtype of non-small cell lung cancer (NSCLC). Squamous cell lung carcinoma accounts for roughly 30 percent of all lung cancers.

What Is Squamous Cell Lung Carcinoma?

Squamous cell carcinoma is a type of NSCLC, which itself makes up around 84 percent of all lung cancer cases. Other types of NSCLC include adenocarcinomas and large cell carcinomas.

The main difference between each subtype of NSCLC is the lung cells that are cancerous. In squamous cell carcinomas, cancer forms in squamous cells, which are flat, thin cells that look similar to fish scales when viewed under a microscope. Squamous cell tumors tend to form in the central part of the lung or in one of the bronchi (main airways). They tend to be centrally located on X-rays.

Squamous cell carcinomas are strongly associated with cigarette smoking. Other risk factors include:

• Exposure to secondhand smoke, radon, asbestos, diesel, and mineral dust
• Older age
• Family history

Signs and Symptoms of Squamous Cell Lung Carcinoma

Lung cancer symptoms begin when a tumor presses against other organs in the body or causes damage. Consequently, symptoms of lung cancer often do not occur until the disease has progressed into an advanced stage. Common signs and symptoms of lung cancer include:

• Chest pain that worsens with coughing, laughing, or deep breathing
• Coughing up blood
• Persistent cough
• Shortness of breath and wheezing
• Recurring lung infections, such as pneumonia or bronchitis
• Unexplained weight loss
• Pain in the back, bones, joints, and head
• Fatigue
• Dizziness
• Swollen lymph nodes

Diagnosing Squamous Cell Lung Carcinoma

To confirm a diagnosis of squamous cell lung carcinoma, your doctor will typically perform several diagnostic tests including imaging tests, biopsies, and laboratory tests.

Imaging Tests

Imaging tests are used to help doctors visualize lungs to identify cancer and determine if the cancer has spread.

X-rays are usually the first test your doctor will perform to look for any abnormal masses in the lungs.

Your doctor may also order a CT scan. A CT scan generates detailed images of the lungs, lymph nodes, and other parts of the body using X-rays taken at multiple angles.

MRI can also be helpful. MRI generates detailed images of the body using strong magnets and radio waves. MRI is commonly used to look for lung cancer that has spread to the brain or spinal cord.

Biopsies and Other Lung Tests

Your care team will also need to look at your lung cells under a microscope to diagnose lung cancer. The lung tissue or cells can be collected from a tissue biopsy, a sample of sputum (mucus), or fluid surrounding the lung. Several methods can be used to take samples for examination.

• Needle biopsy —A hollow needle is inserted into the area where cancer is suspected, removing a small amount of lung tissue.
• Bronchoscopy — A thin, flexible tube with a camera and light attached to the end is inserted through the mouth or nose and travels down into the lungs. A bronchoscopy helps doctors look for tumors and blockages in the bronchi, where squamous cell lung carcinoma develops.
• Sputum cytology — Samples of sputum (the mucus you cough up) are collected and analyzed for cancer cells. This method may be best for diagnosing squamous cell lung carcinoma and other lung cancers that develop in the main airways.
• Thoracentesis — A hollow needle is inserted into the space between the ribs to drain fluid surrounding the lungs. This fluid can be analyzed for cancer cells.

Laboratory Tests

Your doctor may choose to run some laboratory tests to check your overall health. Blood chemistry tests can give your doctor a broad look at the levels of various substances in the body. A complete blood count may also help determine the numbers of different blood cells in the body, which may be affected by cancer.

Genetic testing may also be done to look for mutations commonly found in lung cancer. Squamous cell lung carcinomas often contain “driver mutations,” which are responsible for causing the cancer. These can include mutations in the genes for:

• PTEN, which occurs in 18 percent of cases
• FGFR1, which occurs in 17 percent of cases
• PIK3CA, which occurs in 14 percent of cases
• EGFR, which occurs in 5 percent of cases

Identifying these genetic mutations can help guide your treatment plan, as some mutations respond better to some treatments than others do.

Stages of Squamous Cell Lung Carcinoma

A doctor will use diagnostic test results to determine the type, stage, and grade of a person’s cancer. The stage of cancer describes the size and spread of the tumor and acts as a basis for treatment.

NSCLCs such as squamous cell lung carcinoma are staged using the TNM staging system. "TNM" refers to "tumor, nodes, and metastasis."

• Tumor — Takes into account the size of the main tumor and if it has grown into any neighboring organs or structures
• Nodes — Refers to any cancer spread to lymph nodes near the main tumor
• Metastasis — Refers to the spread of cancer to other parts of the body, such as the bones, liver, brain, adrenal glands, or the other lung

NSCLC can be divided into four stages, 1 through 4. The higher the number, the more the cancer has spread. In addition, letters can also be used within stages. For example, stage 2A is less severe than stage 2B. Sometimes, the stage is written with Roman numerals, e.g., stage III instead of stage 3.

More recently, grouping cancers into the following stages has become more common:

• Localized — The cancer has not spread beyond where it started.
• Regional — The cancer has spread to the lymph nodes.
• Distant — The cancer has spread to other organs.

Treatment Options for Squamous Cell Lung Carcinoma

Once squamous cell lung cancer has been diagnosed, your doctor will consider the results of your diagnostic tests to create your suggested treatment plan. These plans can comprise several types of treatment, including surgery, chemotherapy, radiation, and medications. The exact plan will usually depend on factors including the severity of your cancer, your overall health, other underlying conditions you may have, and your personal preferences.

Surgery

Surgery is often used to treat early stages of squamous cell lung carcinoma, particularly if the cancer is only in one lung, has not spread within the chest or to other parts of the body, and can be removed without causing more harm. Surgery also can be useful for treating one or only a few metastases. Surgery offers the best chance for achieving complete remission (when all traces of the cancer have disappeared) if the entire tumor can be removed.

Surgeries to treat lung cancer include:

• Lobectomy — Removal of the entire lung lobe that contains tumors; the preferred operation for treating NSCLC, if technically possible
• Wedge resection — Removal of part of a lung lobe, performed if a person cannot undergo a lobectomy
• Pneumonectomy — Removal of the entire lung, performed when the tumor is located near the center of the chest

Chemotherapy

Chemotherapy uses anticancer drugs to kill rapidly dividing cells in the body. Chemotherapy medications can be injected into a vein (administered intravenously) or taken as a pill by mouth. Both traditional and platinum-based chemotherapy drugs are used to treat squamous cell lung carcinoma, including:

• Pemetrexed (Alimta)
• Carboplatin
• Cisplatin
• Gemcitabine (Gemzar)
• Paclitaxel (Taxol)
• Docetaxel (Taxotere)

Radiation Therapy

Radiation therapy uses beams of radiation to kill cancer cells by damaging their DNA. The most common type of radiation therapy used to treat squamous cell lung carcinoma is external beam radiation therapy (EBRT). EBRT uses radiation delivered from the outside of the body to the area where the tumor is. More focused and breathing-synchronized methods of radiation are also available.

Targeted Therapy

Targeted therapies refer to drugs that target specific mutations found in cancer cells, but not in healthy cells. For example, Gilotrif (afatinib) — approved by the U.S. Food and Drug Administration (FDA) — targets the EGFR mutation.

Immunotherapy

Immunotherapy takes advantage of the body’s immune system by helping it recognize and kill cancer cells. There are currently several FDA-approved immunotherapy drugs for treating NSCLC and squamous cell lung carcinoma, including:

• Durvalumab (Imfinzi)
• Pembrolizumab (Keytruda)
• Cemiplimab-rwlc (Libtayo)
• Nivolumab (Opdivo)
• Atezolizumab (Tecentriq)
• Ipilimumab (Yervoy)

Angiogenesis Inhibitors

Angiogenesis refers to the process of making new blood vessels. Tumors can hijack the angiogenesis process to form their own blood vessels, which provide oxygen and nutrients to the tumor. Inhibitor drugs have been developed that prevent tumors from forming their own blood vessels, causing the tumors to shrink and die.

The FDA has approved two angiogenesis inhibitors for treating NSCLC, but only one has been approved for squamous cell lung carcinoma. Ramucirumab (Cyramza) is combined with the chemotherapy Taxotere to treat people with advanced NSCLC — particularly those whose cancer has progressed after treatment with a platinum-based chemotherapy.

Bevacizumab (Avastin) is also approved for treating NSCLC, but this drug cannot be used to treat squamous cell lung cancer due to a serious risk of bleeding in the lungs.

Prognosis of Squamous Cell Lung Carcinoma

Doctors sometimes look at survival rates as a prognosis guide. Survival rate refers to the percentage of people who will be alive at a certain time after diagnosis. Overall, the survival rate for NSCLC, including squamous cell lung carcinoma, depends on the stage and spread of cancer. The five-year survival rate for local NSCLC that has not spread is 63 percent. Across all stages, the survival rate is 25 percent. Your health care provider will be able to provide a prognosis specific to your diagnosis.

Talk With Others Who Understand

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