In depth analysis on lung cancer

Lung cancer is one of the most common cancer in India (about 6.8% of total Indian population is affected by it). It is the most common cause of cancer related deaths in men and the second most common cause of death in women. Lung cancer alone is responsible for 1.3 million deaths worldwide annually. 

Causes

The main causes of lung cancer include carcinogens (such as those in tobacco smoke), ionising radiation, and viral infections. This exposure causes cumulative changes to the DNA in the tissue lining the bronchi of the lungs (the bronchial epithelium). As more tissues become damaged, eventually a lung cancer develops.

o  Smoking is the single most important cause. Because of increase in smoking habit, the number of lung cancer cases has markedly increased in last 20 years. Smoking, particularly of cigarettes, is by far the main contributor to lung cancer. The length of time a person smokes increases the person's chance of developing lung cancer. If a person stops smoking, this chance steadily decreases.

o  Air pollution: Gases emitted by industries and vehicles are carcinogenic.

o  Radioactivity chemical exposure: Arsenic, nickel, chromium. (People working in these industries should wear industrial masks).

o  Asbestos: Asbestos can cause a variety of lung diseases, including lung cancer. There is a synergistic effect between tobacco smoking and asbestos in the formation of lung cancer. 

Symptoms

o  Smoker's cough that persists or becomes intense. o  Increase in volume of sputum. o  Wheezing.

o  Non-smoker's cough that persists for more than 2 weeks.

o  Change in colour of sputum.

o  Blood in sputum.

Other symptoms that can be related to late-stage lung cancer

o  Fatigue.

o  Loss of appetite.

o  Facial Palsy.

o  Headache, bone pain, aching joints.

o  Bone fractures not related to accidental injury.

o  Neurologic symptoms, such as unsteady gait and/or episodic memory loss.

o  Unexplained weight loss.

Treatment

Treatment for lung cancer depends on the cancer's specific cell type, how far it has spread, and the patient's performance status. Common treatments include surgery, chemotherapy, and radiation therapy.

Surgery

Surgery is the main modality of treatment for early lung cancer. If investigations confirm lung cancer, CT scan and often positron emission tomography (PET) are used to determine whether the disease is localised and amenable to surgery or whether it has spread to the point where it cannot be cured surgically.

Radiotherapy

Radiotherapy is often given together with chemotherapy, and may be used with curative intent in patients with lung cancer who are not eligible for surgery. 

Chemotherapy

Chemotherapy is an important aspect of treatment of lung cancer. Most lung cancer patients require chemotherapy. The latest development is the treatment of lung cancer includes targeted therapies. These targeted therapies hit specific targets which are present on cancer cells. Hence, these therapies are considered superior than conventional chemotherapies. 

—Dr Meenu Walia, Consultant, Medical OncologyDharamshila Hospital and Research Centre (India's First and Only NABH Accredited Cancer Hospital)