Lung cancer is a common type of cancer and a leading cause of cancer deaths. It can be in primary or secondary stages. When this cancer originates in the lung, it is called "primary lung cancer", but if it originates elsewhere in the body and spreads to the lungs, it is called “secondary lung cancer”. It is important to differentiate between the two from treatment perspective.
Primary lung cancer can be divided into two main types based on the appearance of cancer cell under a microscope: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Non-small cell lung cancers are more common than SCLC. The NSCLC form about 80% of lung cancers, while small cell lung cancer accounts for the remaining 20%.
Symptoms of lung cancer can be variable and in early stages, signs and symptoms may not be evident. Hence many lung cancers are diagnosed in later stages. According to studies, about 25% of people with lung cancer may not show any symptoms, and the cancer may be discovered accidentally on a routine chest X-ray or CT scan. Some symptoms which may occur in a person with lung cancer include:
Lung cancers in most cases grow rapidly and can spread to the bones, brain or other parts of the body.
Risk factors: Factors which increase a person’s risk of developing lung cancer include:
Treatment of lung cancer is influenced by many factors such as:
As no single treatment works for all patients, treatment is usually a combination of therapies and palliative care. Treatment options for lung cancer include:
Treatment for lung cancer is not very effective. Prognosis for lung cancer is poor as compared to most other cancers. Even with treatment only about 5-10% of patients with SCLC are able to live five years after diagnosis. Similarly in NSCLC, response to treatment is not good except in smallest of cancers that can be surgically removed.