Types Non-small cell cancer contains at least three distinct types—squamous cell, large cell and adenocarcinoma—but the treatment of all three is generally similar. Squamous cell carcinoma is the most common type, but for reasons not understood adenocarcinoma is increasing in frequency.
Squamous cell (epidermoid) carcinoma of the lung is the microscopic type most frequently related to smoking. This type is also more commonly associated with spread of the tumor to distant sites (metastasis), but surgical removal of the tumor along with the nearby lymph nodes more often produces a cure than in other types.
Adenocarcinoma of the lung accounts for 30 percent of all lung cancer cases. It is more common in women and is the most frequent type seen in non-smokers, although it occurs in smokers as well. It is more likely than other types to be in the peripheral portions of the lung (near the edge) and therefore may invade the lining of the chest and produce fluid in the chest cavity more commonly than in other types.
Large cell carcinoma of the lung is more commonly associated with spread of the tumor to the brain.
How It Spreads Non-small cell cancer can spread by the lymphatic system and through the blood. It can also directly invade to involve the center of the chest (mediastinum), the lining of the chest, the ribs or, if it is in the top part of the lung, the nerves and blood vessels leading into the arm. When this kind of cancer enters the bloodstream, it can spread to distant sites such as the liver, bones, brain and other places in the lung.
