The symptoms of lung cancer usually appear after the cancer has progressed. However, the chances of successful treatment are much higher in early-stage lung cancers. The goal is always to detect and diagnose lung cancer at an early stage.
The most reliable way to diagnose early-stage lung cancer, as recommended by the World Health Organization, is for individuals at high risk of developing lung cancer to undergo low-dose screening computed tomography (CT) annually.
Individuals at risk for lung cancer are defined as those aged 50–80 years who currently smoke 20 pack-years or have quit smoking within the last 15 years, those with first-degree relatives (parents or siblings) who had lung cancer, or individuals with COPD or pulmonary fibrosis. These individuals are removed from the screening program after reaching the age of 81 or if more than 15 years have passed since they quit smoking.
In diagnosing lung cancer, physical examination conducted by the doctor is extremely important. During the examination, abnormalities such as changes in physical appearance, hoarseness, changes in breathing sounds, or swelling in various parts of the body may be detected.
The most important radiological examination method is computed tomography (CT). A CT scan of the lungs provides a clear picture of all diseases in the lungs, including millimeter-sized lesions. If cancer is suspected, the size of the tumor and its relationship to surrounding structures such as the heart, airway, esophagus, and ribs can be detailed.
A standard chest X-ray is not sufficient to detect early-stage lung cancer. Therefore, it is not possible to definitively rule out lung cancer based solely on a standard chest X-ray taken as part of a routine check-up program.
In cases where lung cancer is suspected, the CT scan should be carefully reviewed by an experienced radiologist, pulmonologist, or thoracic surgeon. If the CT scan detects a suspicious lesion, the doctors will plan the next steps. If no suspicious findings are present and the patient belongs to the risk group mentioned above, it is recommended to repeat the CT scan after one year.
If a suspicious lesion is detected on the CT scan, the following steps are taken:
1. Performing PET-CT. This nuclear medicine examination evaluates the activity (growth rate) of the suspicious area or lesion in the lung and determines whether there are other potential cancerous areas in the body.
2. Direct surgical removal of the suspicious lesion: If a high-risk lesion for lung cancer is identified and the PET-CT confirms the likelihood of cancer, your doctor may recommend the removal of the lesion through a minimally invasive surgery (video).
3. Needle biopsy: If the lesion is suspicious for cancer but surgery is not feasible due to the tumor’s spread or the patient’s overall health, a needle biopsy is preferred. This procedure is performed by an interventional radiologist using CT guidance. The biopsy sample is examined by a pathologist to determine if cancer cells are present.
4. Bronchoscopy: This endoscopic procedure involves examining the airways using a camera inserted through the mouth or nose. Performed under general anesthesia by a pulmonologist or thoracic surgeon, it is suitable for diagnosing lesions located in or near the airway. However, not all lung lesions can be diagnosed through bronchoscopy. Thus, a “clean” result from bronchoscopy does not definitively rule out the presence of lung cancer.
5. MRI: An MRI of the chest or upper abdomen may be necessary for situations where CT or PET-CT cannot clearly differentiate certain conditions.
6. Mediastinoscopy: This surgical procedure is used to biopsy lymph nodes or to determine the cancer stage when other diagnostic methods are insufficient. A 3–4 cm incision is made in the neck area, and a lighted device is used to biopsy lymph nodes for pathological examination.
7. Surgical biopsy: If other methods are insufficient for a definitive diagnosis of a lung lesion, a biopsy is performed using a minimally invasive surgical method known as VATS.
