Lung cancer is the uncontrolled growth of lung cells. Lung cancer can spread to adjacent tissue or beyond the lungs. There are two types of lung cancers small cell lung carcinoma and non-small cell lung carcinoma. This differentiation is important for treatment.
The treatment differs depending on this distinction. The non-small cell lung carcinoma is the most common type of lung cancer. Lung cancers generally spread to brain, adrenal glands, liver, bones, opposite lung, kidney and pericardium.
Lung cancer is mainly caused due to carcinogens like tobacco smoke, viral infections and ionizing radiations. It causes changes in the nuclear material of the cells lining the bronchi.
The lung cancer in non-smokers is due to asbestos, presence of high levels of arsenic in drinking water, radon gas, radiation therapy to the lungs, second hand smoke, air pollutants and genetic factors. There are some chemicals identified as cancer causing chemicals like uranium, vinyl chloride, nickel chromates, mustard gas, coal products, gasoline, diesel exhaust, chloromethyl ethers and beryllium. Exposure to these chemicals can cause lung cancer.
Smoking, exposure to radon gas, being women, exposure to asbestos or other carcinogens, alcohol abuse and family history of lung cancer are the risk factors for lung cancer.
Breathlessness, coughing and blood in cough are the main symptoms of lung cancer.
Wheezing, chronic cough, change in coughing pattern, hoarseness of voice, difficulty in swallowing, facial swelling, facial paralysis, eyelid drooping, bone pain, bone tenderness, clubbing of fingernails, chest pain, loss of appetite, fatigue and weight loss are some other symptoms of lung cancer.
If the cancer is in the airways then it obstructs the airflow and cause breathing difficulties. There may be fluid accumulation behind the blockage that may cause pneumonia. In some patients there are no symptoms and the cancers are found during routine chest radiographs.
Lung cancer is diagnosed based on medical history, physical examination, sputum cytology test, chest radiograph and bronchoscopy. CT scan (Computerized Tomography) and positron emission tomography are used to find out the extent of spread for the purpose of selection of treatment. The diagnosis is confirmed by biopsy of the lung. Blood tests and spirometry are done to find out patient’s fitness if surgery is required.
Chemotherapy, radiation therapy, surgery and targeted drug therapy are the treatment options for lung cancer. Treatment depends on stage of cancer, type of cancer, overall health of the patient and personal preferences. Lung carcinomas of small cell type are treated by radiation and chemotherapy whereas lung carcinomas of non small cell type are treated by surgery.
The prognosis depends on the type of cancer, extent of spread (stage), age of the patient, overall health of the patient and patient’s response to the treatment. Earlier the diagnoses of cancer better the survival rate.
Quitting tobacco smoking, avoiding passive smoke, avoiding industrial and domestic carcinogens and eating lots of fruits and vegetables can prevent lung cancer.
