not provide as much protection against cancer are said to be genetically susceptible to the disease. There are scientists working to understand the genetics involved in lung cancer. Researchers have shown that some cancers involve genes that are passed down from parents to their children, but the link to heredity has not been absolutely confirmed in lung cancer. Lung cancer is one of the most common cancers in the United States. It represents about 15% of all cancer cases as of 1997. Lung cancer accounts for over one-fourth of cancer deaths in the United States It is the number one killer by cancer, it in fact kills more people than colon, prostate and breast cancer combined. At this time, over half of the lung cancer cases in the United States are in men, but the number of women diagnosed each year is increasing and will soon equal that in men. Today more women die of lung cancer than of any other cancer, and lung cancer also kills more men than any other cancer.There are two major types of lung cancer. One is non-small-cell, which is about 80% of all the cases, and small-cell, which is about 20% of all the cases. The names refer to the kinds of cell that make up the tumor rather than the size of the tumor. Non-small-cell lung cancer is classified into three subtypes: adenocarcinomas, which are found in the mucus glands, squamous or epidermoid carcinoma which is located in the bronchial tubes, and large-cell carcinoma is found near the surface. Most of the cases of lung cancer begin in one lung. If left untreated it can spread to lymph nodes or other tissues in the chest, including the other lung. Lung cancer can spread throughout the body, to the bones, brain, liver, or other organsThe signs or symptoms of lung cancer could take years to appear and are at times confused for a less serious illness. Some symptoms or signs may not appear until in and advance stage of the disease. Some symptoms include; changes in a "smokers cough", chan...
