Stage of a cancer is the assessment of the severity of the cancer. It is the measurement of the extent to which the body is affected by the cancer. It evaluates the cancer size and how much it penetrates into its surrounding tissue. This helps to determine the way of the treatment for particular stage and to estimate any patient’s prognosis. Lung cancer therapies also geared towards specific lung cancer stages.
Various tests are used by the doctors in order to identify the lung cancer stages. This includes blood chemistry test in laboratory, X-rays and several scans like CT scan, bone scan, MRI and PET scan. The presence of metastases in bone or lever can be signalled by the abnormal blood chemistry. The size of the cancer and its severity can be filed by the radiological procedures like CT scan helps finding the cancer that has spread towards the liver, brain or other parts and is done by injecting a contrast material in the mouth, bone scan is for identifying cancer in the bone by the injection of a radioactive substance, MRI shows the picture of brain, bone and other limbs by using a powerful magnet and PET scan where a small amount of radioactive sugar is injected. In all cases the injected material is linked to a computer that helps in picturing the affected tissue activities.
Lung cancer stages are assigned into four stages depending on their severity. Stage 1 is tiny and limited. Here the cancer is restricted to the lung only. In stage 2 and 3 the cancer spreads in the surrounding area with bigger and more insidious tumour. The cancer becomes more severe and spreads to the other body parts in stage 4. The cancer is called secondary or metastatic cancer when it spreads to the remote parts of the body. But if the cancer returns to its position after preliminary treatment, it is then called recurrent cancer.
The staging can be varied according to two types of lung cancer that is small cell lung cancer and non small cell lung cancer. Small cell lung cancer stages are of two types: Limited disease where the cancer cells are visible in only one lung. It can also be seen in the lymph node or in pleural effusion which is fluid of around the lung. Another one is extensive disease where the cancer cells spread outside the lung whether may be in chest or other body parts.
Non- small cell lung cancer stages are of four types: stage 1, where the cancer cell are confined in a location and is not spread to anywhere else. This stage can be divided in another two parts: stage 1A, where the cancer size is maximum 3cm and stage 1B, where the cancer is more than 3 cm. Here the cancer grows in the major airways of lung (bronchus). It can also spread to the membrane that covers the lung (pleura).
Stage 2 lung cancer can also be divided into two types: stage 2A, where the cancer is less than 3 cm and the lymph nodes nearby can be affected. In stage 2B, the cancer may be in the lymph nodes or the tumour can collapse lung. Again it can also be in the chest wall, in the membrane that covers the lung name pleura, in the muscle layer under the lugs (diaphragm) or in the pericardium that covers the heart.
Stage 3 includes three stages. In stage 3A, the cancer can be of any size which can spread into the lymph nodes or in the chest middle which is called mediastinum rather than other side. The cancer can also be spread around the tissue that was attacked first, in the chest wall, lung cover or pleura or in other lymph nodes that near to the affected one. Stage 3B can be spread towards lymph nodes on collar bone, chest sides, gullet, heart, windpipe or trachea or towards the major blood vessel. In this case, two or more tumours can be there in the same lung. Again, there can be cancer cells round the lung that contain a set of fluid which is known as pleural effusion.
Stage 4 lung cancer spread to more extent and more distant body parts. This extent can be to the liver, bones or brain.
There are different lung cancer stages systems. As staging helps to identify the potency of the cancer so it is vital for the treatment of the cancer that is performed based on its severity. Patients should go for regular check up to their health care providers in order to be informed about their lung cancer treatment so that necessary steps can be taken accordingly as in preliminary stage most of the times it is possible to be fully cured.