Lung Cancer Types

Lung cancer divides into two major types’ non-small cell and small cell lung cancer. This dividing is very important to get the prognosis of lung cancer.

Non-small cell lung cancer (NSCLC)

From all lung cancer cases about 75% of them are non-small lung cancer. There are three subtypes of non-small cell lung cancer adenocarcinoma, squamous cell carcinoma, and large cell lung cancer.

Adenocarcinoma is the most common of non-small cell lung cancer and counting 40% of all. Adenocarcinoma was previously known as the most common type of lung cancer in women and non-smokers, however, the incidence of adenocarcinoma has increased in the last two decades and it is now the most common histological subtype in both males and females. The reason for the increasing incidence of adenocarcinoma is not well understood, but may be related to changing patterns of smoking. Adenocarcinomas tend to be peripherally located, smaller and vary histological from well-differentiated tumours to solid masses with occasional mucin-producing glands and cells.

A subtype of adenocarcinoma, the bronchioloalveolar carcinoma, is more common in female never-smokers, and may have different responses to treatment. Bronchioloalveolar carcinoma is a very rare type of lung cancer.

Accounting for 25% of lung cancers, squamous cell lung carcinoma usually starts near a central bronchus. A hollow cavity and associated necrosis are commonly found at the center of the tumor. Well-differentiated squamous cell lung cancers often grow more slowly than other cancer types.

Small cell lung cancer (SCLC)

Small cell lung cancer is a less common lung cancer type, from all lung cancer cases about 25% of them are small cell lung cancer. Small cell lung cancer (SCLC) is characterized by small cells that multiply quickly and form large tumors that travel throughout the body. Almost all cases of SCLC are due to smoking.

When a tumor is found to contain a mixture of both small cell carcinoma and non-small cell carcinoma, it is classified as a variant of small cell carcinoma and called a combined small cell carcinoma. Combined small cell carcinoma is the only currently recognized variant of small cell carcinoma.

In infants and children, the most common primary lung cancers are pleuropulmonary blastoma and carcinoid tumor.

Main article: Lung Cancer