Lung cancers are tumours that usually first appear in the lining of the bronchi or bronchioles. These are the small tubes in the lungs that breath passes through. As the tumours enlarge they can block off the bronchi and make breathing difficult. They commonly spread into the local lymph nodes and occasionally the chest wall. This reduces the airways capacity leading to shortness of breath and coughing.
Most forms of lung cancer will spread, most often into the local lymph nodes and occasionally the chest wall. Two common kinds of lung cancer can grow so fast that they often spread to other parts of the body before they can be found and treated. These kinds of cancers make up almost one third of all cases.
Some forms grow slowly, and can often be found and treated before they spread outside the lungs. Some rarely spread at all, but those make up a very small portion of all lung cancer cases.
All types of lung cancer are aggravated by smoking and make treatment more difficult.
The Cancer Society has written a valuable resource for lung cancer patients, which you can download below
Lung Cancer Matepukupuku Pukahukahu
In more detail
There are three general types of lung cancer: small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC), and lung carcinoid tumours.
SCLC, found in about 10-15% of all lung cancer cases, is very aggressive and fast growing. It almost always spreads to other parts of the body before it is diagnosed, making SCLC very difficult to treat.
NSCLC makes up the majority of lung cancers, accounting for 85-90% of all cases. It comes in three subtypes: Between 25-30% of lung cancers are squamous cell carcinomas, which are most likely to be linked to a history of smoking. It attacks the flat cells that line the lung’s airways, and is most often found near a bronchial tube.
Adenocarcinomas make up 40% of cases, and are usually found in the outer part of the lungs. Slower growing than other types of lung cancer, they’re more often found before they spread to other parts of the body.
About 10-15% of lung cancers are large cell carcinomas. This is a fast growing NSCLC cancer that, like the SCLC, spreads quickly and is difficult to treat.
The third type of lung cancer, lung carcinoid tumours, occur in less than 5% of cases. They are a type of neuroendocrine tumour that mostly grow slowly and almost never spread.