Non-small cell lung cancer is the most common type of lung cancer. It usually grows and spreads more slowly than small cell lung cancer. Lung cancer starts when cells of the lung become abnormal and start to produce out of control. As more cancer cells develop, they can form into a tumor and spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer? .
Types of non-small cell lung
cancer
There
are 2 main types of lung cancer:
- About 80% to 85% of lung cancers are non-small
cell lung cancer (NSCLC)
- About 10% to 15% are small cell lung cancer (SCLC)
These types of
lung cancer are treated very differently. This
information covers only non-small cell lung cance.
There are subtypes of NSCLC, which start from different types of lung cells. But they are grouped together as NSCLC because the come up to treatment and prognosis (outlook) are often similar.
Adenocarcinoma: About 40% of lung cancers are
adenocarcinomas. These cancers start in premature versions of the cells that
would normally secrete substances such as mucus.
This
type of lung cancer occurs mainly in current or former tobacco users, but it is
also the most common type of lung cancer seen in non-smokers. It is more
experienced by women too than in men, and it is more likely to occur in younger
people than other types of lung cancer.
Squamous cell (epidermoid)
carcinoma: About
25% to 30% of all lung cancers are squamous cell carcinomas. These cancers
start in early versions of squamous cells, which are flat cells that line the
inside of the airways in the lungs. They are often linked to a history of
smoking and tend to be found in the central part of the lungs, near a main
airway (bronchus).
Large cell (undifferentiated)
carcinoma: This
type accounts for about 10% to 15% of lung cancers. It can appear in any part
of the lung. It tends to grow and spread quickly, which can make it harder to
treat. A subtype of large cell carcinoma, known as large
cell neuroendocrine carcinoma, is a fast-growing cancer that is very
similar to small cell lung cancer.
Other types of lung tumors
Along
with the 2 main types of lung cancer, other tumors can occur in the lungs.
Lung carcinoid tumors: Carcinoid tumors of the lung account for
fewer than 5% of lung tumors. Most of these grow slowly. For more information
about these tumors, see Lung Carcinoid Tumor.
Other lung tumors: Other types of lung cancer such as adenoid
cystic carcinomas, lymphomas, and sarcomas, as well as benign lung tumors such
as hamartomas are rare. These are treated differently from the more common lung
cancers and are not discussed here.
Cancers that spread to the
lungs: Cancers
that start in other organs (such as the breast, pancreas, kidney,
or skin)
can sometimes spread (metastasize) to the lungs, but these are not lung
cancers. For example, cancer that starts in the breast and spreads to the lungs
is still breast cancer, not lung cancer. Treatment for metastatic cancer to the
lungs is based on where it started (the primary cancer site).
