Information on Lung Cancer:
Types of lung cancer
Primary lung cancer is found in two different forms. These are known as small cell and non-small cell lung cancer. Of lung cancer cases, approximately one fifth are small cell cancers and the remainder are non-small cell cancers.
Small cell lung cancer:
Small cell carcinoma is the most aggressive form of lung cancer if it doesn’t receive prompt treatment. Compared with the other types of lung cancer, it unfortunately has a much greater tendency to have spread to other parts of the body by the time it is diagnosed – which just illustrates the need for early diagnosis techniques. In numerical terms, only 40% of patients diagnosed with small cell carcinoma have the cancer restricted to the lung of origin.
Non-small cell lung cancer:
There are three types of non-small cell lung cancer. The most common type is Squamous cell carcinoma, which develops from the cells that line the airways. Adenocarcinoma is a cancer that originates from the cells that produce mucus in your lungs and airways. The third variety, large cell carcinoma, is named after the appearance of the large rounded lung cells that can be seen when they are examined under a microscope.
Mesothelioma is a fourth type of cancer to affect the lungs but is much less common. This cancer affects the pleura – cells that line the lungs, and is often associated with exposure to asbestos.
The causes of lung cancer
I am sure you are aware that tobacco – particularly cigarette smoking, is now known to be the greatest cause of lung cancer. There is a clear relationship between the amount you smoke and your risk of developing the condition, with people who start to smoke at a young age being at an even greater risk. Smoking filtered cigarettes and brands with a low tar content does reduce the risk by a small margin but you are still at a much greater risk than a passive smoker or a non-smoker.
The important thing to note is that it is never too late to reap the benefits of giving up smoking. If a heavy smoker gives up cigarettes today, their lung cancer risk will be only slightly greater than that of a non-smoker within 15 years.
For non-smokers, passive smoking has been proven to increase your risk of lung cancer. Although this risk is less than if you smoked yourself, it is still something that should be avoided if at all possible.
Until more recently, lung cancer has been more common in men than women – especially in those over 40 years old, but along with the increase in female smokers, there has also been a marked increase in cases of women with lung cancer.
Radon gas is thought to be the second largest cause of lung cancers in the UK. It is a naturally occurring gas that can accumulate in your home, having seeped from the soil into the foundations of the property. Radon gas is only found in certain areas of the country, such as the Peak District, but if you are worried about this, you can have your home monitored by the National Radiological Protection Board. Adequate ventilation is often the answer to an elevated level of gas in your home.
Exposure to certain harmful chemicals and substances such as asbestos has also been linked to lung cancer, but these are very rare causes.
The symptoms of lung cancer
Lung cancer presents itself in different ways, but is likely to include one or more of the following symptoms:
- a chest infection that does not seem to be getting any better,
- shortness of breath,
- chest discomfort – such as pain when you cough or breath deeply, or a dull ache,
- a persistent cough,
- coughing up blood-stained phlegm (sputum),
- unexplained weight-loss or loss of appetite.
These symptoms can also be present in other conditions, but if you are experiencing any of the above, we recommend that you see your doctor immediately.
How is it diagnosed?
Having been referred to your local hospital by your GP, there are a number of diagnostic techniques employed to diagnose lung cancer.
The doctor will ask you some questions to establish your medical history before conducting a physical examination. Often, a chest x-ray is taken to check for any visible abnormalities in your lungs, but you may also be asked by your GP to bring samples of phlegm to the hospital with you so that it can be examined under a microscope for cancer cells. This is known as sputum cytology.
Additional tests include:
Bronchoscopy: This procedure involves using a narrow, flexible tube called a bronchoscope to examine the inside of the patient’s lung and airways. Under local anaesthetic, the doctor may also take cell samples or biopsies.
Mediastinoscopy: This procedure is carried out under general anaesthetic, using a tube that allows the doctor to view the inside of the chest through a small incision (at the base of the neck). The doctor can check for signs of cancer and can take samples of cells from your lymph nodes. This is of value because the lymph nodes are often the first place that cancer spreads to.
Lung biopsy: Lung biopsies are usually carried out under local anaesthetic during a CT scan. Patients are asked to hold their breath while a thin needle is passed into the lung through the chest – in order to remove some cells. The CT Scan is used to make sure that the correct area of cells is being sampled. The cells are then sent to the laboratory for analysis.