Lungs are two spongy organs present in our chest. Function of lungs in our body is:
• To transport the oxygen present in inhaled air to body tissues through blood.
• To transport Carbon dioxide from body tissues to outside.

       Cancer of lungs is most commonly diagnosed cancer in the world. It is second most common cancer in males after prostate cancer and second most common cancer in females after breast cancer.

       Lung cancer occurs most often between 40 to 70 years of age. Peak incidence is observed in the 50s or 60s.



COMMON CAUSES OF LUNG CANCER:-

1. Smoking:-
Most lung cancers are associated with well-known carcinogen-cigarette smoke. Increased risk becomes 60 times greater among habitual heavy smokers compared with non smokers.

Even non smokers can develop lung cancer. Passive smoking (proximity to cigarette smokers) increases the risk of lung cancer development to approximately twice that of non smokers. About 80% of lung cancers occur in active smokers or those who have stopped recently. Each year about 3000 non smoking adults die of lung cancer as a result of breathing second hand smoke.



2. Industrial hazards:-
High dose ionizing radiations are carcinogenic.
Industrial exposure to chemicals like asbestos, arsenic, chromium, uranium and mustard gas also increases the risk of lung cancer.

Increased risk of lung cancer is observed among survivors of Hiroshima and Nagasaki atomic bomb blasts as well as Chernobyl disaster.

Asbestos workers who do not smoke have 5 fold high chance of developing lung cancer and those who smoke have 55 fold greater chance !

3. Air pollution:-
Continuous exposure to air particulates in smog may cause irritation of lungs, this increases the risk of lung cancer. The chances are much higher in smokers.

A specific form of air pollution that contributes to increased risk of lung cancer is Radon gas.

Radon is naturally occuring radioactive gas which may be found in indoor enviroments such as homes, schools and workplaces. Radon is the most important cause of lung cancer after smoking.

SYMPTOMS OF LUNG CANCER:-

There are no signs and symptoms in earliest stage. They usually appear in advanced stage of disease such as:
• Cough.
• Chest pain.
• Dyspnea (difficulty in breathing).
• Weight loss.
• Blood in sputum.
• Hoarseness.

Lung Cancers are broadly classified into two types :
• Small cell type.
• Non small cell type.
Non small cell type is further of two types:
1. Squamous cell carcinoma.
2. Adenocarcinoma.

▪ Squamous cell carcinoma:-
It is more common in males than in females.
Very strongly associated with smoking. In this type there is abnormal rise in blood Calcium levels.

▪ Adenocarcinoma:-
It is more common in females than in males.
It is not associated with smoking.

▪ Small cell carcinoma:-
This type of lung cancer is more common in males with strong relationship to cigarette smoking. They are most aggresive type of lung tumors. Other symptoms observed in this type of tumor are low blood calcium level, low sodium ion level, Cushing syndrome due to high level of a hormone in body called ACTH.



PREVENTION:-

1. Avoid smoking.
2. Avoid passive smoking.
3. Start exercising.
4. Take proper precautions when in highly polluted areas or if you work at a place where you are exposed to radiations or other harmful chemicals.
5. Get your home checked for Radon gas.