Lung cancer includes two main types: non-small cell lung cancer and small cell lung cancer. Smoking causes most lung cancers, but nonsmokers can also develop lung cancer.
Risk factors for lung cancer include the following:
- Smoking cigarettes, pipes, or cigars, now or in the past. This is the most important risk factor for lung cancer. The earlier in life a person starts smoking, the more often a person smokes, and the more years a person smokes, the greater the risk of lung cancer.
- Being exposed to secondhand smoke.
- Being exposed to asbestos, arsenic, chromium, beryllium, nickel, soot, or tar in the workplace.
- Air pollution.
- Having a family history of lung cancer.
- Being infected with the human immunodeficiency virus (HIV).
- Taking beta carotene supplements and being a heavy smoker.
Signs of non-small cell lung cancer include a cough that doesn’t go away and shortness of breath.
If you experience symptoms such as long-term respiratory problems and persistent cough, your doctor will perform routine tests to rule out possible causes other than lung cancer, such as lung infection. If you cough out blood, you should be sent directly to undergo a pulmonary radiography.
Other signs of lung cancer include:
- Chest discomfort or pain.
- A cough that doesn’t go away or gets worse over time.
- Trouble breathing.
- Blood in sputum (mucus coughed up from the lungs).
- Weight loss for no known reason.
- Feeling very tired.
- Trouble swallowing.
- Swelling in the face and/or veins in the neck.
If your doctor thinks that you may be developing a lung tumor, he/she will ask you to perform a series of exams to confirm or deny his/her suspects.
The pulmonary X-Ray is usually the first investigation to diagnose lung cancer. Most pulmonary tumours appear on X-rays as a white-grey mass. However, pulmonary X-rays cannot provide a definitive diagnosis, as it cannot distinguish between cancer and other diseases, such as pulmonary abscess (a collection of pus that is formed in the lungs). If it is lung cancer, you will undergo several tests to determine to what extent the tumour has spread, such as a CT scan.
A CT (computed tomography) scan is usually performed after the pulmonary X-ray. Following it, a PET-CT may be necessary. This can be done if the CT examination results show that you have cancer in an early stage. The PET-CT specimen can show where there are active cancer cells. It helps in diagnosis and treatment.
If the CT scan shows that there may be cancer in the central part of the chest, you will undergo a bronchoscopy. The bronchoscopy is a procedure that allows a doctor or nurse to harvest a few cells from the lungs. During a bronchoscopy, a thin tube, called a bronchoscope, is used to examine the lungs and to harvest a sample of cells (biopsy). The bronchoscope is either passed through the mouth or through the nose, passed down on the throat and the airways of the lungs. The procedure is not comfortable, but you will be given a mild sedative beforehand to help you relax, as well as a local anesthetic to numb your throat. The procedure is very fast and lasts only a few minutes.
If for some reason you are not able to undergo a bronchoscopy, it is possible to perform a cytological sputum examination instead. It involves the collection of a sputum sample, which will then be microscopically analyzed for the presence of cancer.
Following the bronchoscopy, a biopsy will be performed. It involves collecting a sample from a suspected tumour mass to be tested in the laboratory for the presence of cancer cells. The doctor performing the imaging-guided biopsy will localize the tumour and guide the percutaneous fine needle to the tumour. A local anaesthetic is used to numb the surrounding skin, and the needle is inserted through the skin into the lungs. The needle will then be used to take a tissue sample to be microscopically analysed to determine the nature of the tumour.
Lung cancer treatments may include Surgical operations, Chemotherapy, immunotherapy and Radiation Therapy. The way the radiation therapy is given depends on the type and stage of the cancer being treated. External and internal radiation therapy are used to treat lung cancer, and may also be used as palliative therapy to relieve symptoms and improve quality of life.
Depending on the exact location and size of the tumor, Radiotherapy treatments for lung cancer can last from 4 to 6 week.
Some tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are usually called follow-up tests or check-ups.