The different types of lung cancer
Generally speaking, there are two broad types of lung cancer -
non-small cell lung carcinoma and small cell lung carcinoma. Lung cancer
is a malignancy that forms in the lung tissues; the cells that line the
air passages are the most common location for this type of cancer.
Small cell lung carcinoma (abbreviated SCLC) is often treated with a
combination of radiation and chemotherapy. Non-small cell lung carcinoma (NSCLC)
is treated with surgery, in many cases. The distinction between these two
types of lung cancer is important because the treatment adopted depends on
the cancer type.
Lung cancer is usually caused by tobacco use. This is the single most
common cause of lung cancer. Non-smokers account for only about 10% of
those affected by the disease. Here, the causes appear to be inhalation of
second-hand smoke as well as exposure to polluted air, radon gas or
asbestos. Genetic factors also play a role.
Of the two types of lung cancer, non-small cell lung carcinoma is more
common. It accounts for around 80% of all cases of lung cancer. Small cell
lung cancer makes up about 17% of lung cancer cases.
The term carcinoma refers to malignant growths that originate in a group
of cells called the epithelial cells in the lung.
Contrary to popular belief, lung cancer does not strike all of a sudden.
It usually develops over several years. In its early stages, it does not
give rise to any noticeable symptoms and is therefore often not detected
until it has turned much more aggressive. Lung cancer that has gone beyond
the early stages can be observed in a CT scan or a chest x-ray.
Confirmation of the presence of lung cancer is done with a biopsy.
The two types of lung cancer differ in the appearance as well as size of
the malignant cells that are present. These differences can be observed
under a microscope by trained professionals.
Non-small cell lung carcinomas are classified into three main types of
lung cancer - large cell lung carcinoma, squamous cell lung carcinoma and
Large cell lung carcinoma accounts for about 10% of cancers. It is
dangerous because it spreads to other parts of the body quite early. It
usually develops near the surface of the lung and grows very fast.
In contrast, squamous cell lung carcinoma mostly develops in the vicinity
of a central bronchus. This is a relatively slower growing type of lung
cancer and accounts for about 31% of lung cancers.
Adenocarcinoma is usually the result of smoking and accounts for about 30%
of lung cancers. It is also one of the most common types of lung cancer in
people who have never smoked. It starts in the peripheral tissues of the
Small cell lung carcinoma is commonly found in habitual smokers. It is
also called oat cell carcinoma. It is one of the types of lung cancer that
grows rapidly. In the initial stages of treatment, small cell lung cancer
responds well to chemotherapy. However, the outlook for patients with this
type of cancer is worse mainly because it usually spreads to other parts
of the body before being detected.
Doctors are careful to differentiate among the various types of lung
cancer because each type responds differently to specific treatment
options. A patient's treatment regimen is determined taking the cancer
type into account.