It is the hysterical growth of abnormal cells in the lungs. Lung cancer develops in the cells lining air passages. These abnormal cells don’t carry out the functions of normal lung cells and do not develop into healthy lung tissue. Instead, they grow and divide rapidly, thus forming tumors and interferes with the functioning of the lung, which provides oxygen to the body via the blood.
Lung cancer is a fatal disease with about 80 percent of its deaths resulting from smoking and also caused by exposure to cast-off smoke. Smoking is the dominant risk factor for it, but there are also other factors involved. Smokers are exposed to other risk factors like asbestos and radon.
Types of lung cancer
Non-Small Cell Lung Cancer (NSCLC)
NSCLC is the most common type of this cancer, making up 80-85 percent of all the cases. Typically, it grows and spreads more gradually than the small cell lung cancer (SCLC). Lastly, the stage of NSCLC depends on the size of the primary tumor and which parts of the body it has spread. Some cancer tumors are primarily from cells of more than one type of NSCLC. (1)
We listed below some of the most common kinds of NSCLC:
Adenocarcinoma: It starts in the cells that form the lining of the lungs and has gland-like properties. Minimally invasive adenocarcinoma (MIA) is a classification to help describe certain, smaller adenocarcinoma lung tumors. Furthermore, Adenocarcinoma makes up to about 30 plus percent of lung cancer diagnoses.
Adenocarcinoma in situ (AIS) (formerly bronchioloalveolar carcinoma or BAC) – it’s a rare subset of adenocarcinoma that begins in the alveoli and can spread without destroying other tissues. It makes up about 3% of lung cancer diagnoses.
Squamous cell carcinoma: It begins in the thin, flat cells that line the passages of the respiratory tract making up just under 30% of lung cancer diagnoses.
Large cell carcinoma: Poorly differentiated – has none of the features that would allow it to be diagnosed as another type of NSCLC. A large cell carcinoma is a faster-growing form of NSCLC that makes up about 9% of lung cancer diagnoses.
Large cell neuroendocrine tumors: Neuroendocrine tumor is a tumor that forms in hormone-releasing cells. It’s the fastest growing type of NSCLC making up about 2% of lung cancer diagnoses.
Small Cell Lung Cancer (SCLC)
Small Cell Lung Cancer (SCLC) makes up 15-20 percent of all lung cancer occurrences. It is a type of neuroendocrine tumor with cells that are smaller in size than most of the other cancer cells. It is also fast-growing cancer that spreads rapidly to other parts of the body. Some lung cancer tumors contain cells that are both SCLC and a form of NSCLC, often large cell.
Mesothelioma: Mesothelioma is a cancer of the lining of organs and not only can originate in the lungs but also the abdomen, heart, and chest.
Carcinoid tumors: Carcinoid tumors are a type of neuroendocrine tumor. There are two types: typical and atypical. They usually start in the neuroendocrine (hormone-producing) cells that line organs such as the small intestine but also the lungs. (1)