What Is Lung Cancer?
Lung cancer is a type of cancer that occurs when malignant (cancerous) cells begin to grow rapidly and uncontrollably in the lung(s). The two main types of lung cancers are small cell and non-small cell lung cancer which are staged differently.
Lung Cancer is among the most common cancers and most common causes of cancer deaths worldwide. In 2018 alone, over 1.5 million deaths occurred due to this cancer.
Lung cancer Overview
Even though the main cause of this cancer is not known, your risks of developing it can be increased by factors such as smoking and exposure to toxic substances like radon and radioactive substances.
Lung cancer can be diagnosed through tests such as imaging tests like x-ray and other more advanced tests like magnetic resonance imaging (MRI), computerised tomography (CT) and positron emission tomography (PET) scans.
The treatment of lung cancer highly depends on its staging which will be the main focus of this article.
As the main cause of lung cancer is not known, it can only be prevented by reducing risk factors such as smoking and exposure to harmful environmental substances which can increase your risk for this cancer.
Lung Cancer Staging
The staging of lung cancer is very important in guiding specialists to determine which treatment is the most appropriate. The TNM system is what is applied in lung cancer staging to determine the following:
- T: the size of the tumour and where it is located in the lung(s),
- N: the node involvement; whether the cancer has spread to the lymph nodes near the lungs,
- M: metastasis; whether the cancer has spread to other parts of the body such as the lung, the liver, brain, kidneys or bones, among other organs.
Staging for the Main Types of Lung Cancer
As stated earlier, the two main types of lung cancers; small cell and non-small cell, are staged differently.
Small Cell Lung Cancer Staging (SCLC)
This is accounts for about 20% of lung cancer cases and is mostly caused by smoking. It begins in the bronchi and spreads quickly to other body parts. In staging SCLC, the TNM system can be used putting it in these two main stages:
- Limited Stage: This indicates that the cancer is in one lung and at times, it has spread to the nearby lymph nodes but not to both lungs or any other parts of the body.
- Extensive Stage: This stage on the other hand, indicates that the cancer has spread to the other lung and other parts of the chest and other body organs.
Non-Small Cell Lung Cancer Staging (NSCLC)
This type of lung cancer is more common than SCLC, accounting for approximately 80% of lung cancer cases. The TNM system is the most common way of staging this cancer and it is used together with the numbers X, O, 1, 2, 3 or 4 after each letter which describe:
- The width of the tumour in centimetres,
- The location of the tumour in the lung,
- Whether there is more than one tumour in the same lung,
- Whether the airways are blocked or clogged such that it can result to pneumonia or collapse of the lung, and
- Whether the cancer has spread to the lymph nodes or other organs in your body.
The stages of non-small cell lung cancer are as follows:
- Occult Stage: This cancer is found in the sputum; however, the tumour cannot be seen on an imaging scan or a biopsy. That is why it is referred to as hidden cancer.
- Stage 0: In this stage, the tumour is still very small, and the cancer cells have not spread to the deeper tissues of the lungs or outside the lungs.
- Stage I or 1: Cancer in the lung tissues but not in the lymph nodes.
- Stage II or 2: The cancer might have spread to the nearby lymph nodes or into the chest wall.
- Stage III or 3: The cancer has spread further into the lymph nodes or the nearby structures and organs like the trachea, oesophagus and heart.
- Stage IV or 4: The lung cancer has metastasized (spread widely) throughout the body and to other body organs like the brain, liver and bones.
After your doctor or specialist has done the lung cancer staging, they can now move on to determining which treatment is best.
Lung cancer staging is a very important process in dealing with this kind of cancer and therefore should be taken seriously and done properly.