What is Lung Squamous Cell Carcinoma? What Are Its Symptoms?

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Lung squamous cell carcinoma is a malignant tumor included in the non-small cell lung cancer group and constitutes a significant portion of lung cancers. Non-small cell lung cancers account for approximately 85% of all lung cancers, and 30% of these consist of squamous cell carcinomas.

Generally seen in individuals over 50 years of age, squamous cell carcinoma tends to progress slowly. However, it is often at an advanced stage when diagnosed. Especially in early stages (Stage 1 and 2), the 5-year survival rate can range between 53-92%, whereas in Stage 3 this rate drops to 13-36%, and in Stage 4 it falls below 10%.

In this article, you will find what lung squamous cell carcinoma is, its symptoms, risk factors, and treatment methods in a clear and understandable way. You will also learn about important symptoms such as unexplained weight loss (unexplained weight loss of more than 5% within 6-12 months).

What is Lung Squamous Cell Carcinoma?

Lung squamous cell carcinoma is a type of malignant tumor that tends to develop in the large bronchi of the lung. This type of cancer occurs when the squamous cells lining the inner surface of the bronchi grow abnormally and multiply uncontrollably. Developing particularly in the large airways (bronchi) of the lung, this disease is generally more common in men, though it is also showing a gradual increase in women.

Structure and functions of squamous cells

Squamous cells are specialized cells in our body that have important protective functions. These cells form the outermost layer of the skin, protecting it against sunlight, chemicals, germs, and physical injuries. They also line many internal surfaces that come into contact with the external environment or are exposed to frequent friction, such as the mouth, throat, esophagus, lungs, cervix, anus, and vagina.

Examined under a microscope, healthy squamous cells appear flat and thin, with a central nucleus and a small amount of clear cytoplasm. Being arranged in regular layers gives the tissue a smooth and even surface. In other words, these cells are strongly attached to each other, with tight junctions between them.

The primary function of squamous cells is to act as a protective shield. Inside organs, they protect delicate tissues from friction, irritation, and infection. These cells constantly renew themselves - old or damaged cells naturally shed and are replaced by new ones.

Its place among non-small cell lung cancers

Lung squamous cell carcinoma is an important subtype of non-small cell lung cancers. The vast majority of this group is associated with smoking.

Squamous cell carcinomas account for approximately 30% of non-small cell lung cancer cases. This cancer type begins in the tissues lining the airways in the lungs and usually tends to be located in the central parts, close to the main airway (bronchus) of the lungs.

As the most common type of lung cancer in our country, squamous cell cancer is seen more frequently in men. The disease is often confined within the lung or spreads to neighboring lymph nodes. This type of cancer usually progresses slowly, but it is often at an advanced stage by the time it is diagnosed.

Is there a difference from epidermoid carcinoma?

Epidermoid carcinoma is another name for squamous cell carcinoma. Therefore, there is no difference between them. In medical literature, both terms are used to describe the same type of cancer.

Epidermoid carcinoma, also known as squamous cell carcinoma, originates from squamous cells that appear flaky and flattened. These terms can be used interchangeably and refer to the same disease.

Closely associated with smoking, this type of cancer is mostly seen in individuals over the age of 50. Genetic predisposition, environmental factors, and chronic lung diseases are among the main causes that increase the risk of this cancer.

What Are the Symptoms of Squamous Cell Carcinoma?

Early diagnosis of squamous cell carcinoma can be life-saving. The symptoms of this cancer often progress silently and can be difficult to notice. Since disease symptoms may not appear in the early stages, it manifests itself in later periods. Recognizing these symptoms is of great importance for early diagnosis.

Persistent cough and blood in sputum

A persistent cough lasting longer than two weeks, gradually worsening and of undetermined cause, is the most prominent indicator of lung cancer. Smokers often attribute their cough to smoking and pay no attention to it. However, this situation can lead to overlooking an important symptom.

Seeing blood in the sputum or the sputum turning dark brown is also a serious symptom of lung cancer. Especially if there is blood in the sputum, this situation should not be delayed. Bloody sputum can also be observed in the early stages of lung cancer.

Shortness of breath and wheezing

Tumor cells in the lung block the airways and put pressure on the lungs. As a result, breathing comfortably becomes difficult, and patients experience shortness of breath. Additionally, a wheezing sound may be heard in the chest while breathing.

Wheezing refers to breathing with a high-pitched sound. This condition occurs as a result of the blockage of the bronchi and is among the important symptoms of lung cancer.

Chest pain and hoarseness

Tumors pressing on nerves cause chest pain in patients. Especially pain occurring in the chest region while coughing or breathing can be an indicator that cancer cells have started to spread outside the lung.

Hoarseness can occur as a result of tumors developing in the upper lobes of the lung putting pressure on nerves. In cases of hoarseness lasting longer than ten days without an underlying problem such as infection or reflux, a physician must be consulted.

Loss of appetite and weight loss

Loss of appetite and weight loss are frequent symptoms in lung cancer. Along with cancer, the metabolic rate changes, and the body directs the energy of the calories taken toward fighting the tumor instead of muscle regeneration.

Cancer cells consume many times more energy than normal cells. Therefore, involuntary weight loss occurs.

Fatigue and weakness

Weakness can be seen at any stage and can be an early harbinger of lung cancer. The rapid metabolism of cancer cells quickly depletes the body's energy reserves, and this situation can lead to severe weakness.

Recurrent lung infections

Pneumonia cases recurring particularly in the same area can be a harbinger of another problem such as a tumor in that region. Recurrent infections unresponsive to treatment are an important symptom of lung cancer.

In pneumonia cases that do not improve despite antibiotic treatments and recur more than once in the same region, the presence of an underlying tumor should be considered. In this case, advanced examinations should be performed without wasting time.

Causes and Risk Factors of the Disease

Many factors play a role in the development of lung squamous cell carcinoma. Knowing the causative factors and risk factors of this disease is important in terms of understanding prevention methods.

Smoking and passive smoking

The most important cause of lung squamous cell carcinoma is smoking. 85-90% of all lung cancer cases are related to smoking. Tobacco smoke contains more than 4,000 chemicals and over 70 carcinogenic substances. This type of lung cancer has a stronger link with smoking compared to other non-small cell types.

Passive smoking, which poses a major risk even for non-smokers, increases the likelihood of developing lung cancer by 20-30%. The smoke inhaled as a result of passive smoking is a mixture of smoke coming directly from the cigarette and that produced by the smoker's breathing. In the event of quitting smoking, the risk decreases over time and approaches the level of never-smokers after 10-20 years.

Asbestos and chemical exposure

Asbestos is a group of minerals with a heat-resistant fibrous structure. It has been used especially in the construction, shipbuilding, and industrial sectors. Inhaling asbestos fibers damages lung cells and increases the risk of cancer. Research has shown that the risk of developing lung cancer in workers exposed to asbestos is 3 to 4 times higher than in those not exposed.

In addition, exposure to other chemical substances such as arsenic, chromium, nickel, gasoline, coal products, and vinyl chloride can also cause lung cancer. In our country, the production and use of asbestos were completely banned in 2010.

Genetic predisposition and age

In individuals with a family history of lung cancer, the risk of cancer is 2.5 to 4 times higher. However, although genetic predisposition is an important factor, when looking at the overall risk situation, environmental factors are more dominant.

The risk of contracting lung cancer also increases with age. While the disease is rarely seen in individuals under 40 years of age, the risk rises slowly every year after age 40. Squamous cell carcinoma is mostly seen in individuals over 50 years of age and is more common in men.

Air pollution and immune system weakness

Outdoor air pollution alone increases the risk of lung cancer by 10%. The main causes of air pollution are fossil fuel use, industrial facilities, mining, and exhaust fumes. Long-term exposure to particulate matter with a diameter of 2.5 micrometers and below and nitrogen dioxide increases the risk by 8%.

People with a strong immune system can fight cancer cells better. However, chronic lung diseases such as COPD, tuberculosis, and pulmonary fibrosis weaken the immune system, create damage in lung tissues, and can lay the groundwork for cancer. Recurrent lung infections can also increase the risk by weakening the immune system.

Stages and Progression of the Disease

Staging at the diagnostic stage of lung squamous cell carcinoma is of vital importance to predict the treatment plan and the course of the disease. Staging is done according to the size of the tumor, whether it has spread to lymph nodes, and whether it has metastasized to other organs.

Stage 1: Localized tumor

Stage 1 is the earliest stage of the disease, and the tumor diameter is generally smaller than 5 cm. In this stage, the cancer is confined within the lung and there is no spread to the lymph nodes. Since the tumor is still very small, most patients show no symptoms, and the disease is usually noticed incidentally during X-rays taken for other reasons.

Stage 1 is divided into 1A and 1B within itself. In Stage 1A, the tumor is smaller than 3 cm. In Stage 1B, the tumor is between 3-4 cm. In this stage, the 5-year survival rate is around 77-92% in 1A and approximately 68% in 1B, and surgical treatment is the most effective option.

Stage 2: Spread to nearby lymph nodes

In the second stage, the tumor size is generally between 4-7 cm or there is spread to lymph nodes on the same side of the lung. At this stage, cough, bloody sputum, recurrent pneumonia, and other respiratory tract infections may be observed.

In this stage, the cancer is still localized and surgical intervention is an effective treatment method. The 5-year survival rate can vary between 53-60%. In Stage 2, chemotherapy and/or immunotherapy are generally added post-surgery.

Stage 3: Spread to the chest cavity

In the third stage, the tumor size is usually larger than 7 cm and has spread to lymph nodes outside the lung (mediastinal). Symptoms such as chest pain, shortness of breath, difficulty swallowing, and bloody sputum are frequently seen in this stage.

Stage 3 is divided into 3A, 3B, and 3C within itself. In Stage 3A, the cancer has spread to mediastinal lymph nodes on the same side. In Stage 3B, there is spread to lymph nodes on the opposite side or lymph nodes in the neck region. Treatment in this stage is usually a combination of chemotherapy and radiotherapy, and surgery is applied in limited situations.

Stage 4: Metastasis to distant organs

Stage 4 is the most advanced stage of lung cancer, and the cancer has spread to other organs of the body (such as bone, brain, liver, adrenal glands). 60-70% of lung cancers are at stage 4 at the time of diagnosis.

The fourth stage is divided into 4A and 4B. In 4A, cancer cells may be found in the chest wall lining, heart lining, or the opposite lung. In 4B, there is metastasis in multiple organs.

Life expectancy and prognosis according to stage

The course of the disease and life expectancy vary according to the stage at the time of diagnosis. While the 5-year survival rate in Stage 1 is between 68-92%, this rate drops to 53-60% in Stage 2. While the survival rate hovers between 13-36% in Stage 3, this rate is below 10% in Stage 4.

With the use of targeted drugs and immunotherapy, the average life expectancy in Stage 4 patients has extended up to 20 months. However, the prognosis may vary depending on the patient's general health status, the characteristics of the tumor, and the response to treatment.

Diagnosis and Treatment Methods

Successful treatment of lung squamous cell carcinoma depends on accurate and timely diagnosis. Early diagnosis significantly increases patients' treatment options and prolongs life expectancy.

Diagnosis with CT, PET, and bronchoscopy

Diagnosis of lung squamous cell carcinoma usually begins with evaluating the patient's health status. First, a physical examination is performed, followed by imaging methods. Computed tomography (CT) can detect millimetric lesions by creating cross-sectional images of the lungs. If a suspicious area is seen on CT, a PET (Positron Emission Tomography) scan is requested.

A PET scan measures the metabolic activity of cancer cells, allowing them to be distinguished from normal tissues. A SUVmax value higher than 2.5-3 indicates the possibility of cancer in lung lesions. PET also helps determine whether the cancer has spread to other regions of the body.

For a definitive diagnosis, bronchoscopy is performed. In this procedure, direct imaging of the lungs is provided with a camera-equipped device placed into the windpipe. Tissue samples taken via biopsy are examined to confirm the presence of cancer cells.

Surgical intervention

Surgical treatment is the most effective method in early stages (Stage 1 and Stage 2). In lung squamous cell carcinoma, surgery is preferred in situations where the disease has not spread outside the lung. The surgical procedure can be performed via an incision of approximately 15-20 cm on the side of the patient, or it can be carried out using minimally invasive methods.

Lobectomy (removal of one lobe of the lung), segmentectomy (removal of a section of the lung), or pneumonectomy (removal of the entire lung) can be applied. During the surgery, lymph nodes are also removed to check whether the cancer has spread.

Chemotherapy and radiotherapy

Chemotherapy is a treatment using drugs that stop the growth of cancer cells or kill them. It can be applied alone or used before surgery to shrink the tumor or after surgery to destroy remaining cells. It is generally administered intravenously in three-week periods.

Radiotherapy, on the other hand, aims to destroy cancer cells using high-energy rays. It is applied especially in patients without surgical chances or in combination with chemotherapy. Today, thanks to advanced radiotherapy techniques, treatment can be performed with less damage to healthy lung tissue.

Immunotherapy and targeted therapies

Immunotherapy is a treatment method that has shown significant development in lung cancer in recent years. This treatment enables the body to fight cancer by strengthening the immune system. It can provide longer-term survival, especially in advanced-stage patients.

Targeted therapies, on the other hand, target specific genetic changes in cancer cells. When mutations such as EGFR, ALK, ROS1, BRAF are detected, appropriate targeted drugs are used. Unlike chemotherapy, these drugs only affect cancerous cells and are mostly taken orally. Thus, their side effects are fewer, and patients' quality of life can be higher.

Frequently Asked Questions

We answer the most frequently asked questions about lung squamous cell carcinoma for patients and their relatives.

Does quitting smoking really reduce the risk of lung cancer?

Yes, quitting smoking significantly lowers the risk of cancer. Research shows that the risk of contracting lung cancer in those who quit smoking is less than half compared to those who continue smoking. However, the risk of cancer in those who quit smoking is still 9 times higher compared to those who have never smoked.

Can people who have never smoked also contract lung squamous cell carcinoma?

Unfortunately, yes. Although the likelihood of contracting it is lower in non-smokers, genetic factors and passive smoking increase the risk. Additionally, exposure to substances such as asbestos and arsenic also poses a risk.

How do non-small cell lung cancer surgery and chemotherapy affect quality of life?

Surgical intervention and chemotherapy applications can affect quality of life. Nevertheless, thanks to advanced treatment techniques today, the quality of life of patients can be preserved better.

When does lung cancer give symptoms?

Lung cancer typically may not give symptoms in the early stages. Since most patients smoke, they attribute one of the first symptoms, cough, to smoking and do not feel the need to go to the doctor.

In Summary, Lung Squamous Cell Carcinoma

Lung squamous cell carcinoma is a disease with a high chance of treatment when diagnosed early. However, unfortunately, most patients are diagnosed at an advanced stage. Therefore, knowing risk factors and paying attention to symptoms can save lives.

Smoking is the biggest risk factor for this disease. Quitting smoking significantly reduces the risk of the disease. In addition, regular health check-ups are of great importance, especially for those in the risk group.

When symptoms such as persistent cough, shortness of breath, and chest pain are noticed, a doctor should be consulted without wasting time. In case of a cough lasting longer than two weeks and blood in the sputum, immediate medical help must be sought.

Today, thanks to surgery, chemotherapy, radiotherapy, immunotherapy, and targeted therapies, the life spans and qualities of patients are increasing progressively. When diagnosed in early stages (Stage 1-2), treatment success is quite high.

As a result, the most important factor in lung squamous cell carcinoma is early diagnosis. Knowing the symptoms of the disease, avoiding risk factors, and having regular health check-ups play a key role in both prevention and early diagnosis. Adopting a healthy lifestyle and staying away from smoking are the most effective ways to protect against this disease.