What Is Squamous Cell Lung Cancer?
Updated on June 6, 2025
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Squamous cell lung cancer is a type of non-small cell lung cancer (NSCLC). It can also be referred to as epidermoid carcinoma or squamous cell carcinoma of the lung. Squamous cell lung cancer starts in the squamous cells: thin, flat cells that line the inside of the airways in your lungs. It accounts for about 30 percent of all cases of NSCLC.
Squamous cell lung cancer typically grows slowly, but it can spread to other areas of the body. If you're diagnosed after the cancer has spread, it tends to be more difficult to treat. There are a wide variety of treatment options, which are chosen based on the stage of cancer, type of lung cancer, any gene changes, and your health. These range from conventional cancer therapies, such as chemotherapy and radiation, to treatments that target specific genetic mutations.
Types of Squamous Cell Lung Cancer
Squamous cell lung cancer is classified as one of three subtypes based on how the cancer cells look under a microscope:
- Keratinizing: The cancer cells produce a type of protein called keratin, forming keratin “pearls.”
- Nonkeratinizing: These cancer cells don't produce keratin and appear large and dark blue in color.
- Basaloid: These cancer cells resemble the basal cells found in the deepest layers of the lung epithelium, and tend to be arranged in lobules.
Signs and Symptoms of Squamous Cell Lung Cancer
Especially in the early stages of lung cancer, some people may only have mild symptoms, or even no symptoms at all. This is why lung cancer is often detected after it has spread, or metastasized, especially as the symptoms often overlap with other health conditions. Symptoms of squamous cell lung cancer may include:
- A persistent cough
- Coughing up mucus or blood
- Shortness of breath or difficulty breathing
- Wheezing
- Fatigue
- Hoarseness
- Chest pain
- Discomfort when swallowing
- Fever
- Unexplained weight loss or poor appetite
- High levels of blood calcium
If lung cancer spreads, other symptoms can develop, such as:
- Headaches, seizures, or issues with balance, if the cancer spreads to the brain
- Jaundice, if the cancer spreads to the liver
- Bone pain, if the cancer spreads to the bone
Causes and Risk Factors of Squamous Cell Lung Cancer
Cancer happens when gene mutations cause cells in the body to grow abnormally. When it comes to lung cancer, these gene errors are most often acquired as a result of exposure to cancer-causing chemicals, such as those found in tobacco smoke.
Smoking is the cause of most lung cancers. Tobacco smoke contains more than 7,000 chemicals, at least 70 of which are identified as cancer-causing in people or animals. Squamous cell lung cancer is more strongly linked to smoking than any other type of NSCLC.
But, lung cancer also occurs in people who don't smoke or haven't been exposed to secondhand smoke. In these cases, there may be no obvious cause for the cancer, though there are other risk factors that can come into play.
Other risk factors for developing squamous cell lung cancer include:
- Older age
- A family history of lung cancer
- Breathing in secondhand smoke
- Radiation therapy to the chest
- Exposure to cancer-causing agents, such as asbestos, radon, coal products, arsenic, uranium, mustard gas, diesel exhaust, air pollution, or mineral and metal dust
How Is Squamous Cell Lung Cancer Diagnosed?
If squamous cell lung cancer is suspected, healthcare providers will likely first order imaging tests, such as a chest X-ray, computerized tomography (CT) scan, or magnetic resonance imaging (MRI).
Other tests that may be performed to help diagnose squamous cell lung cancer or determine if it has spread outside the lungs include:
- Sputum Sample In this test, a person's mucus is examined for cancer cells.
- Biopsy A biopsy involves taking a small sample of tissue from the lung and analyzing it in a laboratory to look for cancer cells.
- Bronchoscopy A thin instrument with a camera on the end is passed down the throat and into the lungs. Doctors look for cancer and can biopsy tissue.
- Endobronchial Ultrasound This procedure combines bronchoscopy with ultrasound to visualize and sample lung nodules and abnormal lymph nodes. It's minimally invasive compared with bronchoscopy.
- Mediastinoscopy With this procedure, a thin, tube-like instrument is used to look at the organs in the area between the lungs and nearby lymph nodes. Doctors can biopsy tissue and establish whether cancer has spread to lymph nodes.
- Fine-Needle Aspiration A small needle is inserted into part of the lung to biopsy tissue. It can help doctors diagnose the type of cancer.
- Thoracentesis Fluid buildup in the chest is drained with a needle and checked for cancer cells.
- Video-Assisted Thoracoscopic Surgery (VATS) A tube with a camera on the end is inserted into the chest through an incision to examine the space between the lungs and the chest wall for cancer. Lung tissue can also be biopsied.
What Are the Stages of Squamous Cell Lung Cancer?
After diagnosis, your doctor will stage the cancer, based on where it's located and whether or not it has spread. The stages of squamous cell lung cancer are:
- Stage 1 The lung tumors are small and haven't spread to surrounding tissues or organs.
- Stage 2 and Stage 3 The tumors have spread to surrounding tissues or organs and lymph nodes. This can be referred to as regional.
- Stage 4 The lung tumors have spread, or metastasized, beyond the chest.
Treatment Options for Squamous Cell Lung Cancer
Treatment options for squamous cell lung cancer will depend on various factors, such as the stage of the disease, the type, whether certain gene mutations fuel the cancer, and your overall health.
Surgery
If the cancer has not spread outside of the lung, surgery may be an option. There are three main types of lung cancer surgery:
- Wedge Resection A surgeon removes only a small part of the lung.
- Lobectomy One lobe of the lung is removed.
- Pneumonectomy An entire lung is removed.
Chemotherapy
Chemotherapy uses drugs to kill cancer cells in the body, and is normally injected into a vein. When it comes to squamous cell lung cancer, chemo may be given before or after surgery, or to slow the cancer's growth and improve symptoms if the lung cancer has spread. Squamous cell lung cancer doesn't respond as well to chemotherapy and radiation as other types of tumors.
Commonly used chemotherapy drugs for squamous cell carcinoma are:
- cisplatin, often combined with gemcitabine
- carboplatin
- albumin-bound paclitaxel
Chemotherapy can have many side effects, including:
- Anemia
- Diarrhea or constipation
- Fatigue
- Hair loss
- Increased risk of infections
- Nausea and vomiting
Radiation Therapy
Radiation therapy uses beams of energy to destroy cancer cells in the body. External beam radiation, which is aimed at the lung cancer from outside the body, is the type most commonly used to treat squamous cell lung cancer.
Some possible side effects of radiation are:
- Fatigue
- Nausea and vomiting
- Radiation pneumonitis, due to changes in lung tissue
- Scarring of the lung
- Shortness of breath
- Trouble swallowing
Targeted Treatments
Targeted treatments focus on certain gene changes in cancer cells. If a person's tumor contains specific abnormalities, these therapies may be effective. These gene mutations tend to occur less frequently in squamous cell lung cancers than in other types of lung cancers.
Your doctor can test your tumor for specific gene defects that may respond to targeted therapies.
Immunotherapy
Immunotherapy involves training your body's own immune system to detect and destroy cancer cells. There are four FDA-approved immunotherapies for people with NSCLC, including squamous cell lung cancer. These drugs are called checkpoint inhibitors, and they encourage the immune system to go into overdrive.
Research has found that the combination of the immunotherapy drug pembrolizumab (Keytruda) with chemotherapy significantly prolonged survival in people with advanced squamous cell lung cancer.
Angiogenesis Inhibitors
Angiogenesis is the process of the body making new blood vessels. Angiogenesis inhibitors prevent these new vessels from forming, which blocks the tumor from having access to blood. Without oxygen and nutrients found in blood, the tumor should die or stop growing.
Ramucirumab (Cyramza) is an angiogenesis inhibitor that is approved to be used with docetaxel, a chemotherapy drug, when the cancer has metastasized.
Can Squamous Cell Lung Cancer Be Prevented?
While there's no definite way to prevent squamous cell lung cancer, you can lower your risk if you:
- Don't smoke or quit smoking.
- Avoid secondhand smoke.
- Test your home for radon: Test kits can be found online or at a hardware store. Your local health department can assist you understand the testing process. If your home tests high for radon, there are ways to lower the levels.
- Avoid exposure to carcinogens If you work with chemicals, make sure to wear appropriate personal protective equipment.
- Eat a healthy diet that includes plenty of fruits and vegetables.
- Exercise: The general recommendation by the American Heart Association is 150 minutes of moderate aerobic activity or 75 minutes of vigorous activity each week.
Additionally, high-risk people should be screened for lung cancer so doctors can diagnose the disease earlier, which could lead to a better prognosis. The U.S. Preventive Services Task Force (USPSTF) recommends annual screening for lung cancer with a low-dose CT scan for adults ages 50 to 80 who have a 20-pack-year smoking history and currently smoke or have quit within the past 15 years.
A “pack year” is defined as a pack of cigarettes a day for a year or an equivalent amount.
What Is the Outlook for Squamous Cell Lung Cancer?
The prognosis for squamous cell lung cancer depends on the stage of the disease, the type, the treatment a person receives, an individual's overall health, and other factors.
If this cancer is detected and treated early, the outlook is much more favorable than if the cancer is in its advanced stages. Unfortunately, squamous cell lung cancer is usually diagnosed after it has spread.
The five-year survival rates for NSCLC are:
- 65 percent for localized disease, meaning the cancer has not spread outside of the lung
- 37 percent for regional disease, meaning the cancer has spread to nearby structures or lymph nodes
- 9 percent for distant disease, meaning the cancer has spread to distant areas of the body, such as the brain, bones, or liver
It's important to note that survival rates are only estimates based on previous data, and they don't take everything into account. Treatments have improved over time, and factors such as age, overall health, lung cancer subtype, gene changes, and how well the cancer responds to treatment will also affect prognosis.
Complications of Squamous Cell Lung Cancer
Complications can vary, based on treatment and stage of the cancer. Surgical treatment can have complications such as:
- Infection
- Air leaks
- Hemorrhage
- Nerve injuries
- Irregular heartbeats
Shortness of breath, coughing up blood, and fluid accumulation in the chest are all additional complications of lung cancer. Cancer that has spread may cause pain or symptoms in other parts of the body.
Who Has Squamous Cell Lung Cancer?
Smokers have the greatest risk of lung cancer, and the majority of people diagnosed with lung cancer are over 65 years old. Men are slightly more likely to have lung cancer than women. Black men are 12 percent more likely to be diagnosed with lung cancer than white men.
While lung cancer is the most common cancer that causes death in the United States, new diagnoses and deaths from lung cancer have been decreasing.
Related Conditions to Squamous Cell Lung Cancer
There are a variety of other types of lung cancer:
- Small cell lung cancer, which account for 10 to 15 percent of lung cancers
- Adenocarcinomas, the most common subtype of NSCLC
- Large cell carcinoma, a subtype of NSCLC
- Rare subtypes of NSCLC, such as sarcomatoid carcinoma
- Lung carcinoid tumors, which account for less than 5 percent of lung tumors
- Rare lung tumors, such as lymphomas or sarcomas
The Takeaway
- Squamous cell lung cancer is a type of non-small cell lung cancer (NSCLC) that starts in the thin, flat squamous cells lining the lungs' airways. NSCLC is the most common form of lung cancer.
- Squamous cell lung cancer is highly linked to a history of smoking, although nonsmokers can still have this type of cancer.
- This type of cancer is often diagnosed after it has spread, which makes it more difficult to treat, but newer treatments may improve outlook.
- Early detection is key, so inform your doctor if you have risk factors, such as family history of lung cancer, or if you're a smoker.
Common Questions & Answers
Is squamous cell lung cancer curable?
Squamous cell lung cancer is potentially curable if caught early (in stages 1, 2, or 3) and the patient can handle aggressive treatment. Treatments for squamous cell lung cancer include surgery, radiation, chemotherapy, targeted therapy, and immunotherapy.
What is the survival rate for squamous cell lung cancer?
The five-year survival rate for all stages of non-small cell lung cancer combined is 28 percent. This is an estimate based on prior data and doesn't predict how long a person with lung cancer will live.
Does chemotherapy work for squamous cell lung cancer?
Squamous cell lung cancer does not respond as well to chemotherapy as some other tumor types, but chemotherapy may be given to slow the growth of the cancer or improve symptoms if the cancer has spread.
Where does squamous cell carcinoma of the lung typically spread?
Tumor cells can metastasize to other parts of the body, including to lymph nodes around and between the lungs, bones, adrenal glands, the liver, and the brain.
Does smoking cause squamous cell lung cancer?
Squamous cell lung cancer is tied to smoking more strongly than any other NSCLC, but lung cancer does occur in people who have never smoked and have not been exposed to secondhand smoke.
Resources We Trust
- Mayo Clinic: Clinical Trials: Squamous Cell Lung Cancer
- American Lung Association: Lung Cancer
- LUNGevity: Transforming Lung Cancer
- Cleveland Clinic: Non-Small Cell Lung Cancer
- CancerCare:Lung Cancer
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
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Tingting Tan, MD, PhD
Medical Reviewer
Tingting Tan, MD, PhD, is a medical oncologist at City of Hope National Medical Center.
Dr. Tan's research has been published in multiple medical and scientific journals, including Oncologists, Cancer Cell, and Genes and Development.
A graduate of the Beijing Medical University, Tan holds an M.D. from Peking University Health Science Center and a Ph.D. from Rutgers University. Her training includes fellowships at the University of California San Francisco Cancer Research Institute and the Fox Chase Cancer Center at Temple University.
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