Lung Cancer: Early Detection, Stages, and Treatment Methods

Lung cancer is a serious respiratory disease that occurs when the cells making up the lung tissue multiply uncontrollably and form a tumor. Detecting the disease in its initial stages is the most critical factor directly affecting treatment success and the patient's life expectancy. Thanks to advancing medical technologies, when lung cancer is diagnosed early, patients' chances of a full recovery increase significantly.

• The most common risk factor is the use of tobacco products and secondhand smoke.
• A persistent cough and blood-tinged sputum are the most frequently encountered early signs.
• Early diagnosis is possible for high-risk individuals through low-dose computed tomography (CT) screening.
• The treatment plan is determined based on the type and stage of the cancer, as well as the patient's overall health.
• In early-diagnosed cases, the chance of a full recovery through surgical methods is high.

What is Lung Cancer?

Under normal conditions, the cells in our body grow, divide, and die in an orderly fashion. In lung cancer, however, the DNA structure of the cells lining the bronchi (airways) or alveoli (air sacs), which allow us to breathe, becomes damaged. These damaged cells multiply rapidly and uncontrollably to form masses, or tumors. Over time, these tumors grow, preventing the lung from performing its normal functions, and can spread to other parts of the body through the blood or lymphatic system.

Lung cancer is the most common type of cancer worldwide and one of the leading causes of cancer-related loss of life. The disease is primarily divided into two main groups based on how the cells look under a microscope. The first of these is non-small cell lung cancer (NSCLC), which accounts for about 80 to 85 percent of cases. The second is small cell lung cancer (SCLC), which tends to grow and spread more quickly. Accurately determining the type of disease is of great importance in shaping the treatment to be applied.

Non-Small Cell Lung Cancer (NSCLC)

This group is further divided into subtypes: adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Adenocarcinoma usually begins in the outer parts of the lung and is the most common type found in non-smokers. Squamous cell carcinoma, on the other hand, typically occurs closer to the center of the airways (bronchi) and has a strong association with smoking.

Small Cell Lung Cancer (SCLC)

Accounting for about 15 percent of cases, this type is almost entirely linked to heavy smoking. Because it consists of very rapidly multiplying cells, it is highly likely to have already spread (metastasized) to other parts of the body by the time it is diagnosed. For this reason, it generally responds better to chemotherapy and radiotherapy rather than surgical intervention.

Causes and Risk Factors

Environmental factors, lifestyle habits, and genetic predisposition all play a combined role in the development of lung cancer. The most fundamental factor paving the way for the disease is the use of tobacco and tobacco products. Dozens of the thousands of chemicals found in cigarette smoke are directly carcinogenic (cancer-causing). These substances damage the genetic structure of lung cells, initiating the cancer process.

People who do not smoke but are exposed to secondhand smoke are also at risk. Passive smoking significantly increases the risk of lung cancer. While infections like Legionnaires' disease, which can spread through air conditioning systems, threaten lung health, the primary triggers for cancer are heavy chemicals that cause cellular mutation.

Other important risk factors include:

• Asbestos Exposure: Inhaling asbestos fibers used in industries like shipbuilding, insulation, and mining severely increases the risk of lung cancer and cancer of the lung lining (mesothelioma).
• Radon Gas: This colorless, odorless gas, formed by the natural breakdown of uranium in soil, poses a danger when inhaled, particularly when it accumulates in basements or poorly ventilated buildings.
• Air Pollution: Long-term exposure to heavy exhaust fumes and industrial waste can cause cellular damage.
• Genetic Predisposition: Individuals with a history of lung cancer in their first-degree relatives have a higher risk of developing the disease.

Symptoms of Lung Cancer

The disease often causes no complaints in its initial stages. Because the lungs have few pain receptors and a large capacity, a tumor can progress silently until it reaches a considerable size. However, when the tumor begins to block the airways or press against surrounding tissues, various symptoms of lung cancer emerge.

Because shortness of breath and wheezing can be confused with other respiratory diseases like asthma, a differential diagnosis is crucial. In the advanced stages of the disease, more systemic and severe signs are observed.

The most common symptoms are:

• A persistent cough that lasts for more than three weeks and gradually worsens
• Coughing up blood or rust-colored sputum
• Chest, back, or shoulder pain that worsens when taking a deep breath, laughing, or coughing
• Unexplained hoarseness or a raspy voice
• Loss of appetite and rapid, unintentional weight loss
• Constant fatigue, weakness, and low energy
• Recurrent respiratory infections such as bronchitis or pneumonia

Stages of Lung Cancer

Determining the extent to which the cancer has spread in the body is essential for creating the most appropriate treatment plan. Lung cancer stages are classified based on the size of the tumor, whether it has spread to the lymph nodes, and whether it has metastasized to other organs.

Staging for non-small cell lung cancer is as follows:

• Stage 1: The tumor is confined to the lung tissue, is small, and has not spread to any lymph nodes or surrounding tissue. This is the most suitable stage for surgical intervention.
• Stage 2: The tumor has grown slightly larger or has spread to the nearest lymph nodes within the lung.
• Stage 3: Cancer cells have spread to the lymph nodes in the center of the chest cavity (mediastinum) or to surrounding tissues like the chest wall or diaphragm. It is further divided into subgroups 3A, 3B, and 3C.
• Stage 4: The cancer has metastasized (spread) to both lungs, the fluid around the lungs or heart, or distant organs such as the brain, liver, bones, or adrenal glands.

How is Lung Cancer Diagnosed?

Lung cancer screening and diagnostic tests play a vital role for patients presenting with suspicious symptoms or for high-risk individuals even if they have no symptoms. Current medical approaches focus on catching the disease before it shows any signs.

Low-Dose Computed Tomography (Screening)

Low-dose computed tomography (LDCT) is the most effective screening method, especially for people over the age of 50 who have been heavy smokers for many years. Containing much less radiation than a standard CT scan, this method can detect even millimeter-sized nodules in the lungs. Through regular monitoring or biopsy of nodules caught at an early stage, the cancer can be brought under control before it spreads.

Imaging and Biopsy Methods

During the diagnostic process, a chest X-ray and a detailed CT scan are performed first. If a suspicious mass is seen, a tissue sample (biopsy) must be taken from that mass for a definitive diagnosis. A biopsy can be performed using different methods:

• Bronchoscopy: A thin, flexible tube with a camera at the tip is inserted through the mouth or nose to examine the airways. Small tissue samples are taken from suspicious areas.
• EBUS (Endobronchial Ultrasound): This is bronchoscopy combined with ultrasound technology. It allows for needle sampling from lymph nodes or masses outside the airways.
• Needle Biopsy: If the tumor is close to the outer parts of the lung, a thin needle is inserted through the chest wall under CT guidance to take a sample.
• PET-CT: Once the cancer diagnosis is confirmed, a full-body scan is performed to see if the disease has spread to any other part of the body (staging).

How is Lung Cancer Treated?

Lung cancer treatment requires a multidisciplinary approach. Pulmonologists, thoracic surgeons, medical oncologists, and radiation oncologists come together to determine the most appropriate plan for the patient. The choice of treatment depends on the type and stage of the cancer, the patient's respiratory capacity, and their overall health.

Surgical Intervention (Lung Cancer Surgery)

Surgery is the primary treatment method for non-small cell lung cancers caught in the early stages (Stages 1 and 2). Through lung cancer surgery, the tumorous tissue and surrounding at-risk lymph nodes are removed from the body. Depending on the size and location of the tumor, it may be necessary to remove one lobe of the lung (lobectomy) or the entire lung (pneumonectomy). Surgeries performed using minimally invasive methods (VATS or robotic surgery) allow the patient to recover faster and experience less pain.

Chemotherapy and Radiotherapy

Chemotherapy is a drug treatment given intravenously to kill cancer cells or stop their growth. It can be used before surgery to shrink the tumor (neoadjuvant) or after surgery to destroy any remaining microscopic cells (adjuvant). Radiotherapy is the process of breaking down the DNA of cancer cells using high-energy rays. It is applied as the main treatment for patients who are not suitable for surgery or to relieve symptoms like pain and bleeding.

Targeted Therapy and Immunotherapy

In recent years, the biggest revolution in lung cancer treatment has occurred in the field of smart drugs and immunotherapy. Targeted therapies find and block specific genetic mutations (such as EGFR, ALK, ROS1) that allow cancer cells to grow. Because these drugs only affect cancerous cells, their side effects are fewer than those of chemotherapy. Immunotherapy, on the other hand, stimulates the patient's own immune system to recognize and destroy cancer cells. It significantly increases life expectancy and quality of life, especially in patients with advanced-stage disease.

Complications and Risk Groups

Untreated or late-diagnosed lung cancer leads to serious complications in the body. The growth of the tumor can block the airways, causing recurrent bouts of pneumonia or lung collapse. If cancer cells spread to the lining of the lungs (pleura), fluid accumulates in the chest cavity (pleural effusion). This fluid presses on the lung, creating severe shortness of breath, and needs to be drained periodically.

Metastasis of the disease to the brain causes headaches, loss of balance, vision problems, and seizures; while bone metastases can cause severe pain and bone fractures. The highest risk group consists of people who have smoked more than a pack a day for many years. Additionally, those working in the chemical, paint, asbestos, and mining industries without using protective equipment are also at high risk.

When Should You See a Doctor?

Symptoms involving the respiratory tract should not be taken lightly. Especially if you smoke or have smoked in the past, you should listen carefully to the signals your body gives. If you experience any of the following situations, you should consult a pulmonologist without delay:

• If your cough has lasted for more than three weeks or has changed character (more frequent, more severe)
• If you see streaks of blood or frank blood in your sputum
• If you have a sharp or constant pain in your chest when breathing
• If you have lost more than 10 percent of your body weight in the last six months without dieting

Situations Requiring Emergency Intervention: In cases such as coughing up a large amount of fresh blood, sudden severe shortness of breath that creates a feeling of suffocation, confusion, or sudden loss of strength on one side of the body, you should immediately call 112 emergency services or go to the nearest hospital emergency room.

The Pulmonology Process at BHT CLINIC

At the BHT CLINIC İstanbul Tema Hastanesi Pulmonology (Chest Diseases) department, the diagnosis and treatment of all respiratory system diseases, including lung cancer, are carried out at international standards. Early diagnosis processes are meticulously managed with our advanced imaging centers, low-dose CT, and PET-CT devices available in our hospital.

Interventional procedures requiring advanced technology, such as bronchoscopy and EBUS, are performed safely and comfortably by our expert medical staff. For our patients diagnosed with cancer, the treatment plan is determined by a joint decision in multidisciplinary tumor boards involving thoracic surgery, oncology, and radiology specialists. Our 24/7 emergency department is fully equipped to immediately intervene in sudden respiratory distress. To benefit from a healthy breath and the life-saving power of early diagnosis, you can consult our specialist physicians by booking an appointment.

Frequently Asked Questions

Can lung cancer be completely cured?

Yes, when the disease is detected in the early stages (especially stages 1 and 2), the chances of a complete recovery through surgical interventions and additional treatments are quite high. In advanced stages, thanks to new-generation smart drugs and immunotherapy, the progression of the disease can be halted, and life expectancy can be significantly extended.

Does lung cancer show up in a blood test?

Standard blood tests (hemogram, biochemistry) are not sufficient to diagnose cancer. Certain tumor markers checked in the blood may give an idea, but a definitive diagnosis is always made through imaging methods (CT scans) followed by a biopsy.

Can a non-smoker get lung cancer?

Yes, lung cancer can also be seen in non-smokers. Factors such as secondhand smoke, asbestos or radon gas exposure, air pollution, and genetic predisposition can cause cell mutation and lead to cancer even in individuals who have never smoked.

How long does lung cancer surgery take?

The duration of the surgery varies depending on the size and location of the tumor, and the surgical technique to be applied (open, minimally invasive, or robotic). Generally, procedures like lobectomy or pneumonectomy are completed in an average of 2 to 4 hours.

Who should get screened for lung cancer?

It is recommended that individuals aged 50-80 who have smoked a pack a day for 20 years or more, and who currently smoke or have quit within the last 15 years, be screened once a year with a low-dose computed tomography scan.

This article is for informational purposes only; please be sure to consult your physician for diagnosis and treatment.