What is Lung Cancer?

Lung cancer originates from cells of the lung. However, this is different from cancers that begin in other parts of the body and have spread to the lung. For example, colon cancer that may have spread to the lungs is still colon cancer. 

There are two main types of lung cancers; these are your small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). The latter, non-small cell lung cancer (NSCLC) is much more common than its counterpart. Treatment of small cell and non-small cell lung cancer are different. 

On top of there being two main types of lung cancer, there are also different subtypes of NSCLC. The most common ones are adenocarcinomas and squamous cell carcinomas. The subtype of NSCLC may affect the type of treatment recommended.  

How Does Lung Cancer Develop? 

Lung cancer is caused by the genetic mutation to cells, causing them to grow abnormally. These abnormal cancer cells may invade normal parts of the body and spread to other parts of the body through the blood or lymphatic vessels. This is called metastasis. 

What the Risk Factors for Lung Cancer 

Several risk factors can lead to lung cancer. Tobacco smoking is the most common risk factor for developing lung cancer. This is the case for both SCLC and NSCLC. Your risk increases over the period you smoke and the amount that you smoke.

Exposure to secondhand smoke is also a risk factor for lung cancer. This is when you do not smoke yourself but breathe in tobacco smoke from your surroundings. 

If you would like to stop smoking and would like some help, kindly speak to your doctor about our Smoking Cessation clinic. 

Additionally, exposure to certain chemicals such as asbestos also increases the risk of lung cancer. Asbestos is a natural mineral and carcinogen. It was used in shipbuilding and the construction industry in the 1960s but has since been banned.  

Symptoms of Lung Cancer 

Chronic cough and breathlessness are the most common symptoms of lung cancer. Coughing up blood, fatigue, pain, loss of appetite and loss of weight are also frequently encountered.  

However, in the early stages, some patients may be asymptomatic and not exhibit any of these symptoms. 

Types of Lung Cancer

As mentioned, there are two main types of lung cancer. They are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). NSCLC is more common than SCLC and accounts for roughly 80% of lung cancers. The remaining 20% are SCLC. The type of cancer affects the treatment plan that will be recommended by your doctor.

There are also subtypes of both NSCLC, as well as other types of lung cancer that are much rarer. They are typically differentiated by the type of cells in the lung from which the cancer develops.

  • NSCLC Subtypes
    • Adenocarcinoma
    • Squamous Cell Carcinoma
    • Large Cell Carcinoma
    • Adenosquamous Carcinoma
    • Sarcomatoid Carcinoma

Another primary difference between NSCLC and SCLC is the rate at which the cancer develops. NSCLC usually develops slower than SCLC. This is one of the reasons why the recommended treatment plans also vary between the two subtypes.