Lung cancer is the leading cause of cancer deaths worldwide, claiming more lives each year than breast, colon, prostate, and ovarian cancers combined. Here, Dr. Yuben Moodley, examines lung cancer, the different types of lung cancer, and discussed the risk factors for developing them.
Types of lung cancer
Non-small cell lung cancer
By far, the majority (about 80% to 85%) of lung cancers are of the NSCLC type. The main subtypes of NSCLC are:
- Adenocarcinoma – This subtype starts in the cells that would naturally secrete mucus substances, mainly in current or former smokers. It is, however, the most common type of lung cancer seen in non-smokers. It is more common in women than in men and is more likely to occur in younger people than other lung cancer types.
- Squamous cell carcinoma – This subtype starts in squamous cells. These are flat cells that line the inside of the airways in the lungs. This type is often linked to smoking history and tends to be found in the lungs’ central part, near a primary airway.
- Large cell carcinoma – This subtype can appear in any part of the lung. It can be challenging to treat because it tends to grow and spread quickly. A type of large cell carcinoma, known as large cell neuroendocrine carcinoma, is fast-growing cancer similar to small cell lung cancer, discussed below.
These subtypes start from different lung cell types but are grouped as NSCLC because their treatment and prognoses are often comparable.
Small cell lung cancer
Sometimes called oat cell cancer, only about 10% to 15% of all lung cancers are SCLC. This type tends to grow and spread faster than NSCLC. It tends to respond well to chemotherapy and radiation therapy, but unfortunately, this type of cancer will return at some point for most people.
Risk factors of lung cancer
People who smoke have the most significant risk of lung cancer. However, lung cancer can also occur in people who have never smoked. The risk of lung cancer increases with time, and the number of cigarettes smoked. Even after smoking for many years, quitting smoking can significantly reduce the risk of developing lung cancer.
Other risk factors for lung cancer include:
- Exposure to secondhand smoke – Even for non-smokers, the risk of lung cancer increases if exposed to second-hand smoke.
- Previous radiation therapy – People who have undergone radiation therapy to the chest for another type of cancer may have an increased risk of developing lung cancer.
- Exposure to radon gas – Produced by the natural breakdown of uranium in soil, rock, and water, radon eventually becomes part of the air you breathe. Unsafe levels of radon can accumulate in an enclosed space, such as a home.
- Exposure to asbestos and other carcinogens – Exposure to asbestos and other substances — such as arsenic, chromium, and nickel — can increase lung cancer risk, especially for smokers.
- Family history of lung cancer – People with a parent, sibling, or child with lung cancer have an increased risk of the disease.
If there is any takeaway from these facts, it is, if you smoke, stop. If you don’t smoke, don’t start.
About Yuben Moodley
Yuben Moodley is a dedicated physician, researcher, and Deputy Director of the Institute of Respiratory Health. His research focuses on investigating mechanisms and finding novel cellular therapies for Idiopathic Pulmonary Fibrosis and Chronic Obstructive Pulmonary Disease. He serves on the National Health and Medical Research Council panel, where he got funding for his research.