Types of Lung Cancer
There are two main types of lung cancer which are both referred to as primary lung cancers.
It’s important to make a distinction between primary lung cancer and cancer which appears in the lung after spreading from another cancer in the body – this is known as secondary cancer.
Lungs are very receptive to other metastasizing (spreading) cancers, particularly bowel cancer and malignant melanoma which is the most aggressive form of skin cancer.
Primary lung cancers include non small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Sometimes, although very rarely, lung cancer can be a mixture of the two and this is known as mixed small cell/large cell carcinoma.
Non small cell Lung Cancer
NSCLC accounts for about 80% of all lung cancers and is made up of three types:
* Squamous cell carcinoma which affects the squamous cells in the lung
* Adenocarcinoma, affecting glandular type cells
* Large cell undifferentiated carcinoma which can affect any part of the lung
The majority of patients with NSCLC are diagnosed very late so treatment is aimed at improving quality of life rather than curing the disease. For those in the initial stages of the disease there is a 70% chance of surviving five years. During the later stages this drops to nine months.
Small cell Lung Cancer
Unfortunately by the time SCLC is diagnosed the cancer has usually spread to another part of the body. SCLC accounts for just 15% of all lung cancers and is far more aggressive than NSCLC. The majority of people with advanced SCLC live just ten months after diagnosis.
SCLC is split into different types depending on which cells in the lungs are affected by the cancer:
* Small cell carcinoma, often referred to as oat cell cancer because the cells resemble oats
* Mixed small cell carcinoma
* Combined small cell carcinoma
Again, like NSCLC, treatment usually focuses on relieving symptoms and improving quality of life rather than a cure.
Other types of Lung Cancer
As well as the two major types of lung cancer there are other types of tumor which can appear in the lungs. It’s important to remember that some of these are benign.
Mesothelioma is usually associated with exposure to asbestos and this cancer is usually found in the lining of the lungs. It generally affects older males and can take up to 40 years before it develops fully and produces any real symptoms.
Among the most “common” of the uncommon tumors are carcinoid tumors which account for about 5% of all lung growths. They affect organs and glands which produce hormones and are far more common in younger people.
The majority of carcinoid tumors are very slow growing and can usually be cured by surgery, although chemotherapy and radiotherapy are sometimes used. They can spread but are not as aggressive as NSCLCs or SCLCs and survival rates are far better.