Lung Cancer

Diagnosis

The diagnosis of lung cancer is made through the following methods:

• Lung cancer screening: The annual lung cancer screening is advised for patients with a smoking history of ≥20 pack-year, who are smoking now or have quit smoking in the last 15 years, and ones between 50 to 80 years. The recommended test for lung cancer screening is low-dose computed tomography. The procedure involves the use of low-dose radiation and is not painful.
• Medical history and examination: The patients are advised not to ignore any pulmonary symptoms, especially if they are at increased risk of lung cancer. During the consultation, the patients are asked in detail about the symptoms, their duration, or if the symptoms are worsening. The medical history and family history of the patients also assist the oncologists in determining the cause of symptoms. If lung cancer or any serious disease is suspected, the patient is recommended to undergo further tests.
• Chest x-ray: The chest x-ray is the initial imaging test to detect the abnormality in the chest. The x-ray provides images of the lungs, heart, airways, blood vessels, chest bone, and spine. A chest x-ray is unable to determine lung cancer at an early stage. However, if the tumor is detected through a chest X-ray, it is usually large, and the disease is advanced.
• Computed tomography: CT scan is one of the most common techniques used for diagnosing lung cancer. Besides detecting the tumors, the CT scan also provides detailed information about the specific features of the lung nodules. This diagnostic procedure is further refined with high-resolution images. There is an increased tumor detection rate with advanced CT procedures, such as helical or spiral CT scans.
• PET-CT scan: Positron emission tomography has high specificity and sensitivity in determining the presence of malignant pulmonary lesions. The combination of CT and PET scans (PET-CT) further enhances the accuracy of diagnosis. PET-CT helps cancer specialists diagnose lung cancer and determine the staging of lung carcinoma, its metastasis, and its response to treatment.
• Lung function tests: The patients may also undergo lung function tests to determine the overall functional capacity of the lungs. Patients with poor lung function are not the ideal candidates for partial lung resection as the remaining lungs cannot fulfill the oxygen requirements. Thus, lung function tests also help in treatment planning.
• Sputum cytology: The sputum samples of the patients are collected and sent to the pathological laboratory to determine the presence of cancer cells. Sputum cytology is only effective in detecting the presence of squamous cell lung cancer that develops in the major airways.
• Thoracocentesis: If there is an accumulation of fluid in the thoracic area, the patients undergo thoracocentesis. The procedure involves removing the fluid and sending the sample to detect the presence of cancer cells.
• Magnetic resonance imaging (MRI): MRI involves using radio waves to detect the spread of cancer to the spinal cord and brain.
• Bone scan: A bone scan is performed to determine the spread of cancer cells to the bones. However, the test is not used frequently, as PET scans can detect the spread of cancer cells to bones.
• Bronchoscopy: The patients undergo bronchoscopy to detect any blockage or tumor in the major lung airways. These overgrowths are then removed for further examination.
• Biopsy: The procedure involves the removal of abnormal tissues from the body parts and evaluating them in the laboratory to detect the presence of cancerous cells. A biopsy may be performed as fine needle aspiration, core biopsy, or transthoracic needle biopsy.