Uncontrolled cell division is the cause of lung cancer. As part of your normal functioning, cells multiply and create more copies. Sometimes, however, these cells get mutations that make them continue to multiply themselves even though they should not. Uncontrolled cell divisions can create tumors of damaged tissue. These masses will eventually stop your organs working.
Cancers of the lungs (usually in the small air sacs or airways, or the bronchi or the bronchioles), are called lung cancer. The cancers that begin in another place and spread to the lungs will usually be named after where they started (your health care provider might refer to it as metastatic lung cancer).
The small cell lung cancer grows faster and is more 肺癌第三期 difficult to treat. The cancer is often diagnosed as a small tumor in the lung that has already spread into other areas of your body. Small cell carcinoma, also known as oat-cell carcinoma and combined small cells carcinoma are two types of SCLC.
There are other types of cancer that can develop in or near your lungs. These include lymphomas, sarcomas and pleural msothelioma. They are usually treated differently, and are not referred to by the term lung cancer.
The stage of cancer is determined by the size and depth of the tumor. It can also be classified according to whether the cancer has spread into lymph nodes, or any other organs. Every type of cancer is treated differently.
There are several possible combinations for each stage in terms of the size and extent. Stage III can have a smaller primary tumor than Stage II, but due to other factors, it is at an advanced stage. You may also hear the stages described as extensive or limited. The area is treated by a single field of radiation.
Cancer that begins in the lung and spreads beyond its original location to another lung or other organs is called metastatic lung cancer. Metastatic lung carcinoma is more difficult to treat than cancers that have not spread beyond their original site. The symptoms of lung cancer are similar to those associated with other less severe illnesses. Some people do not show symptoms until advanced stages of the disease, while others may have them in its early stages. Some people may experience only one or two of the symptoms.
It is possible that a persistent cough or recurrent pneumonia after treatment could be a warning sign for lung cancer. However, it may also indicate underlying conditions. Most common lung cancer symptoms include persistent coughing, chest pains, hoarseness, or weight loss. Some of these symptoms may occur early in the cancer’s progression (stages I or II), but they are often not apparent until later. If you are at a higher risk, it is important to have a lung cancer screening.
Cells that continue to divide even when they should not cause lung cancer. Cell division is normal, but all cells contain a switch to stop them from multiplying (senescence), or to cause them die (apoptosis), when needed. This switch activates when cells have been divided excessively or undergo too many mutations.