Non-small-cell lung cancer
The most common type of lung cancer is non-small-cell lung cancer, accounting for around 80% of all cases.
Non-small-cell lung cancer is divided into three types: squamous cell carcinoma, adenocarcinoma and large-cell carcinoma.
Non-small-cell lung cancer spreads more slowly than the other lung cancer, called small-cell lung cancer.
Non-small-cell lung cancer causes
Smoking is the biggest risk factor for lung cancer, responsible for 90% of cases. Exposure to secondhand smoke also increases a person's risk.
Natural exposure to radon from rocks, soil and in some buildings in parts of the country causes around 3% of lung cancer cases.
Exposure to chemicals and substances at work can increase the risk of lung cancer, including arsenic, asbestos, beryllium, cadmium, coal and coke fumes, silica and nickel.
Non-small-cell lung cancer symptoms
The symptoms of lung cancer are caused by the primary tumour or by metastatic disease. The primary tumour may press on, infiltrate, or damage surrounding tissues, blood vessels, or nerves. Metastatic lung cancer may cause similar problems in other parts of the body. As many as 10% of people with lung cancer don’t show any symptoms. Their cancers are detected on chest X-ray films performed for other reasons.
The symptoms depend on the primary tumour’s size, its location in the lung, the surrounding areas affected by the tumour, and the sites of tumour metastasis, if any. Symptoms related to the primary tumour may include any of the following:
- Shortness of breath
- Difficulty taking a deep breath
- Coughing or spitting blood (haemoptysis)
- Pneumonia or other recurrent respiratory infection
- Pain in the chest, side, or back (usually due to infiltration by the tumour of membranes or tissues surrounding the lungs)
- Hoarseness, difficulty swallowing, or other symptoms in the face, neck, or arms due to infiltration by a tumour
Symptoms of metastatic lung tumours, which have spread from the lung, depend on location and size. Lung cancer most often spreads to the liver, the adrenal glands, the bones, and the brain. About 30-40% of people with lung cancer have some symptoms or signs of metastatic disease.
- Metastatic lung cancer in the liver does not usually cause any symptoms, at least at the time of diagnosis.
- Metastatic spread to the lymph glands may cause a lump to form just above where the collar bone meets the sternum or breast plate. This may be known as a “sentinel node” - a visible warning of a cancer that has spread.
- Typically, metastatic lung cancer in the adrenal glands causes no symptoms at the time of diagnosis.
- Metastasis to the bones is most common with small cell lung cancer but can occur with non small cell lung cancer. Lung cancer that has metastasised to the bone causes deep pain, usually in the backbone (vertebrae), thighbones, and ribs.
- Lung cancer that spreads to the brain can cause difficulties with vision, weakness on one side of the body, seizures, or a combination thereof.
- Weight loss may be a symptom of metastatic disease.
Paraneoplastic syndromes are conditions that the disease causes indirectly. These are less common with NSCLC than with small cell lung cancers, but they do occur.
- High level of calcium in the blood (hypercalcaemia) - can cause problems with muscle and nerve functioning
- Increased production of one or more hormones
- Increased blood coagulation (hypercoagulability) - increases risk of blood clots