Squamous cell carcinoma of the lungs: 5 things to know

Squamous cell carcinoma of the lungs is a type of non-small-cell cancer that originates in the thin, flat cells lining the airways. About 85% of all lung cancers are considered non-small-cell lung cancers, based on how they look under a microscope. Of those, roughly 30% to 35% are categorized as squamous cell carcinomas, while 50% to 60% are adenocarcinomas.

So, how much does it matter which type of lung cancer you’re diagnosed with? And, how might having squamous cell carcinoma affect your lung cancer treatment? We asked Mara Antonoff, M.D., a thoracic surgeon who specializes in lung cancer. Here’s what she shared.

How common is squamous cell carcinoma of the lungs?

Lung cancer is very common in general. It’s the most frequent cause of cancer-related deaths, both in the United States and worldwide. 

Squamous cell carcinoma of the lungs is a bit less common than adenocarcinoma, but it still makes up roughly one-third of all lung cancer diagnoses. So, it is not rare, by any means.

What are the symptoms of squamous cell carcinoma of the lungs?

The symptoms of squamous cell carcinoma of the lungs tend to be no different from those of any other type of lung cancer.

Most people have no symptoms at all in the earliest stages of lung cancer. They only begin to notice symptoms once the tumor is large enough to start impinging on other structures. If a tumor grows into the ribs, for example, you might experience pain. Or, if it grows into the nerve supplying the vocal cords, you might develop a hoarse voice. That’s why roughly 80% of all lung cancer diagnoses are made when the disease has advanced to either stage III or IV.

In general, the most common symptom of lung cancer is a cough that won’t go away, despite normal treatment for lung infections, such as antibiotics. For squamous cell carcinoma, which arises from the cells lining the airways, the tumors may be located on the central airways more frequently, and so may result in coughing or coughing up blood earlier.

Other symptoms include:

• Fatigue
• Shortness of breath
• Wheezing or hoarseness
• Chest, arm, or shoulder pain
• Coughing up reddish phlegm
• Unexplained weight loss
• Recurrent or unresolved respiratory infections like pneumonia or bronchitis

How is squamous cell carcinoma usually diagnosed?

We can’t definitively call anything squamous cell carcinoma until we’ve obtained cells from the tumor and looked at them under a microscope. For patients without symptoms, most cases of lung cancer are found by chance. It can be detected when someone has a CT scan for an unrelated reason, like a car accident or a health evaluation before elective surgery.

People with a history of smoking may also have it detected via lung screening CT scans. If you are a current or former smoker between the ages of 50 and 80, you could be eligible.  

Unfortunately, lung cancer screening is still very underutilized in the United States, though it’s been proven to detect this disease early, when treatment is most likely to achieve a cure. 

No matter how a suspicious lung finding is discovered, though, MD Anderson patients will typically undergo a biopsy to provide a diagnosis of cancer, which will also clarify the subtype and any genetic or molecular features that could be important for deciding treatment.

In addition, patients will also have a staging workup before treatment begins to determine the exact stage of the disease. This includes an evaluation of lymph nodes in the area and a search for any tumor cells that may have spread elsewhere in the body.

How is squamous cell carcinoma of the lungs usually treated?

The answer depends on the stage of the cancer and the person’s overall health. Early-stage lung cancer can often be treated with surgery alone. More advanced cases will involve some combination of systemic therapy (such as chemotherapy, targeted therapy, or immunotherapy) along with surgery and/or radiation therapy.

Adenocarcinomas of the lungs are more likely than squamous cell carcinomas to have a genetic mutation that could make targeted therapy a good treatment option. But it’s still possible for squamous cell carcinomas to have genetic abnormalities, so it’s worth considering molecular testing for those, too.

Are there any risk factors that can make someone more likely to develop squamous cell carcinoma of the lungs?

Yes. Anyone with a history of cancer is at a slightly higher risk of developing cancer again.

But smoking and tobacco use are the biggest risk factors, followed by radon exposure in the home and secondhand smoke. About 80% of all lung cancer diagnoses are related to smoking, and that figure is even higher for squamous cell carcinomas.

If you smoke, quit now. Medication and counseling are the best way to do it. You can call 1-800-784-8669 or text QUIT to 47848. Cancer patients can also join the MD Anderson Tobacco Treatment Program.

Request an appointment at MD Anderson online or by calling 1-877-632-6789.