Types - Small Cell
The vast majority of incidences in lung cancer arise from what are known as carcinomas. These are, in general terms, those malignancies which arise in the epithelial cells. Among these there are generally two types of lung carcinomas that are classified with regards to the size of the malignant cells. They are either small-cell lung carcinomas or non-small cell lung carcinomas, among which the latter is decidedly more prevalent. This classification is often made upon discovery of the cancer by studying the nature of the cells under a microscope by an experienced histopathologist.
Small cell lung carcinomas are much less common than the non-small cell varieties. This type tends to originate in larger breathing tubes and grow incredibly rapidly. An origin, known as an "oat cell," contains dense neurosecretory granules, which cause the tumor's rapid growth. These origin cells prove to be extremely efficient at reproduction, causing the initial tumor to be quite large even when first detected.
One of the unfortunate tendencies of small cell lung carcinomas is their tendency to metastasize quite quickly, often before cancer is even detected. By metastasizing, the cancer will spread to other parts of the body. Metastasis can take place both ways. A tumor developed in the lung may cause a tumor growth in another part of the body, such as the pancreas or kidney. In addition, a relatively tame cancer can develop in breast and metastasize in the lung, becoming a much more serious condition. Often, discovery of a small cell carcinoma will accompany the discovery of other tumors, a sign that the cancer has already reached its metastatic stage.
Small cell lung carcinomas occur are refereed in stages with regards to the level of hazard the body is in. Small cell lung cancer is described as being in "limited stage" if it is restricted to one half the chest, which accounts for the scope within a single radiotherapy field. Otherwise, it is regarded as in "extensive stage," in which case it has likely already metastasized. These stages typically carry much of the weight with regards to how treatable the specific patient's case may be.
Prognosis of lung cancers is by rule, quite poor. In the case of small cell lung carcinomas, this is especially true. While initially sensitive to radiation therapy the disease typically regenerates quickly enough to compensate for any dying cells and continues to spread and metastasize in other areas of the body. 5 years survival rates of those diagnosed with small cell lung cancer are about 5%, while those numbers dip to 1% for those with extensive stage carcinomas.