There are two main sub-classifications of primary lung cancer:

1. Non-small cell lung cancer (NSCLC) – this is the most common form of lung cancer, making up approximately 85% of all lung cancer cases. NSCLC can be classified into a number of types, including:
• Adenocarcinoma – typically found on the outer area of the lungs, in cells that produce mucus
• Squamous cell carcinoma – typically found in the airways of the lungs
• Large cell undifferentiated carcinoma – this type of cancer cannot be classified as either adenocarcinoma or squamous cell carcinoma.
2. Small cell lung cancer (SCLC) – this type of lung cancer tends to spread faster than NSCLC. However it is less common than NSCLC, accounting for approximately 15% of all lung cancers. Lung cancer is one of the most common cancer in Indian males but most patients present in advanced stages because the index of suspicion is low.

1. Smoking - Cigarette smoking carries a significantly higher risk of developing lung cancer when compared with non-smokers.

It is estimated that lung cancer cases as a result of cigarette smoking contribute to 90% of all cases in men and 65% in women

2. Exposure to asbestos and toxins -Contact with asbestos, coal gas and radiation exposure (radon gas) increases risk of lung cancer.
3. Age - The risk of developing lung cancer increases as people age. Most lung cancers are diagnosed in people over the age of 60

The symptoms of lung cancer are vague and hence patients do not seek medical attention in early stages. In few cases, the symptoms are diagnosed during routine health check-ups (X-ray Screening picks up a lung lesion).

The most common symptoms are:

• A cough that won’t go away or a change in a chronic cough
• Shortness of breath or Wheezing (due to a blockage in the windpipe)
• Blood stained sputum
• Chest pain
• Unexplained weight loss
• Hoarseness of voice or Difficulty in swallowing

A patient with suspected lung tumour might be evaluated with any of the following tests, as needed:

• Chest X-ray
• Computerized Tomography Scan (CT Scan)
• Positron Emission Tomography (PET Scan)
• Sputum Cytology
• Bronchoscopy
• Fine-Needle Aspiration/ Biopsy
• Magnetic Resonance Imaging (MRI) of the brain
• Endo Bronchial Ultrasound (EBUS)
• Ventilation/Perfusion Lung Scans
• Blood Tests
• Pulmonary Function Test (PFT)

The main treatments for lung cancer are surgery, radiotherapy, chemotherapy and targeted/ immunotherapy. The choice of treatment will depend on the type of lung cancer, stage of the disease, functioning of lungs and patient`s general health

1. Surgery:

If cancer has not spread beyond the affected lung and same side of mediastinum, if general health is reasonably good, and if breathing capacity is sufficient, the treatment that gives the best chance of cure is Surgery.

Surgical options for lung cancer are

• Lobectomy
• Pneumonectomy
• Segmentectomy
• Sleeve Resection of tumour
• Non-anatomical/Wedge Resection
• Chest wall resection/ Chest wall tumour resection
• Diagnostic Thoracoscopy
• Mediastinoscopy
• Thoracoscopic / minimally invasive lobectomy/ pneumonectomy
2. Chemotherapy:
• Chemotherapy is the treatment of choice for patients with small cell carcinoma.
• In non-small cell carcinoma, patient may need chemotherapy after surgery to remove cancer, to increase the chances of cure. This is called ‘adjuvant’ chemotherapy.
3. Radiation Therapy:
• High-energy beams are used to kill cancer cells and shrink tumours.
• Newer techniques of Intensity Modulated Radiotherapy (IMRT) and Image-Guided Radiotherapy (IGRT) ensure maximum dose to the tumour safeguarding the normal uninvolved part of lung/ heart from adverse effects.
• There is also Gated Radiation Therapy, where the lung tumour is targeted in a particular phase of the breathing cycle.
4. Targeted Therapy / Immunotherapy:
• Some people, usually non-smokers are suitable for a newer class of drugs that are designed to act against specific genes/ mutations in lung cancer cells.
• Targeted therapy / immunotherapy is used in advanced lung cancer patients and improves survival.
• These drugs can also be taken by pill or by IV.