Lung Cancer - Causes, Symptoms, Diagnosis, Prevention & Treatment

Lung Cancer

Dr.K V V N  RAJU profile Authored by Dr.K V V N RAJU on 10 Oct 2014 - 10:11.

Lung cancer is a major problem in both developed and developing countries in the world. It is the leading type of cancer (more than a million new cases; 12.8% of all cancers) and the leading cause of cancer mortality (921,000 deaths ; 17.8% of all cancer deaths) worldwide.

Cancer begins in cells, the building blocks that make up all tissues and organs of the body, including the lungs. Normal cells in the lungs and other parts of the body grow and divide to form new cells as they are needed. When normal cells grow old or get damaged, they die, and new cells take their place. Sometimes, this process goes wrong. New cells form when the body doesn’t need them, and old or damaged cells don’t die as they should. The build-up of extra cells often forms a mass of tissue called a growth or tumor.

Tumors in the lung can be benign (not cancer) or malignant (cancer):

Benign tumors:

  • Are rarely a threat to life
  • Don’t invade the tissues around them
  • Don’t spread to other parts of the body

Malignant tumors (lung cancer):

  • May be a threat to life
  • Can invade nearby organs and tissues
  • Can spread to other parts of the body
  • Often can be removed but may grow back

Types of lung cancer

There are two major types of lung cancer: non-small cell (NSCLC) and small cell (SCLC). They are named for how the lung cancer cells look under a microscope.

It is important for doctors to distinguish NSCLC from small cell lung cancer because the two types of cancer are usually treated in different ways. The type of lung cancer, such as NSCLC or small cell, and stage of the disease determine what type of treatment is needed.


What are the causes/ risk factors of lung cancer?

Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer.

Smoking cigarettes, beedis, is the most common cause of lung cancer. Almost 90 percent of lung cancers result from tobacco use. The earlier in life a person starts smoking, the more often a person smokes, and the more years a person smokes, the greater the risk of lung cancer. If a person has stopped smoking, the risk becomes lower as the years pass.

Risk factors for lung cancer include the following:

  • Smoking cigarettes, beedis, now or in the past.
  • Being exposed to secondhand smoke(passive smoking).
  • Having a family history of lung cancer.
  • Being exposed to asbestos, chromium, nickel, arsenic, soot, tar, radon gas in the workplace or radiation for treatment
  • Living where there is air pollution.

When smoking is combined with other risk factors, the risk of lung cancer is increased.

What are the symptoms of lung cancer?

Sometimes lung cancer does not cause any signs or symptoms. It may be found during a chest x-ray done for another condition. Signs and symptoms may be caused by lung cancer or by other conditions. Check with your doctor if you have any of the following:

  • Chest discomfort or pain.
  • A cough that doesn’t go away or gets worse over time.
  • Shortness of breath, wheezing or hoarseness
  • Blood in sputum (mucus coughed up from the lungs).
  • Recurring infections, such as bronchitis and Pneumonia
  • Loss of appetite/ weight loss for no known reason.

How to diagnose and confirm lung cancer?

Tests that examine the lungs are used to detect, diagnose, and stage lung cancer, to assess the functional status are often done at the same time

  • History and Physical examination
  • Laboratory tests
  • Chest x-ray
  • CT scan (CAT scan)
  • Sputum cytology
  • Fine-needle aspiration (FNA) biopsy of the lung
  • Histopathology and molecular testing 
  • Bronchoscopy
  • Thoracoscopy
  • Thoracentesis
  • Pulmonary function tests (PFT’s)

Staging workup

After lung cancer has been diagnosed, tests are done to find out if cancer cells have spread within the lungs or to other parts of the body which is called as staging. Staging influences the choice of treatment and prognosis.

  • MRI (magnetic resonance imaging) of brain
  • CT scan (CAT scan) of brain, abdomen
  • PET scan (positron emission tomography scan)
  • Radionuclide bone scan
  • Endoscopic ultrasound (EUS)
  • Mediastinoscopy
  • Anterior mediastinotomy
  • Lymph node biopsy
  • Bone marrow aspiration and biopsy

Reducing Your Risk

You can take action to reduce your risk of developing lung cancer. Making the healthy changes below does not mean you will not get lung cancer, but it may lower your chances.

  • eliminate tobacco use
  • use protective equipment when exposed to dangerous substances and pollutants
  • avoid secondhand smoke
  • have diet low in fat and high in fibre with plenty of fruits, vegetables and whole grains
  • indulge in exercise and physical activity         

Take time to discuss your own risks with your health care provider who can best advise you on the screening exams and risk-reduction strategies that are right for you.

What treatments are available?

The goal of cancer treatment is the elimination of the cancer. It involves a combination of treatments involving multi-disciplinary approach.

There are four types of cancer treatments:

  • Surgery
  • Chemotherapy
  • Radiation therapy
  • Targeted therapy

The intent of treatment, whether curative or palliativeand the choice of treatment dependson, among other things, whether or not the disease has spread beyond the lungs and how well the lungs function. Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are treated differently. NSCLC’s are treated with a combination of the above modalities and SCLC’s are treated with chemotherapy and radiotherapy.


Four types of surgery are used to treat lung cancer:

  • Wedge resection: Surgery to remove a tumor and some of the normal tissue around it. When a slightly larger amount of tissue is taken, it is called a segmental resection
  • Lobectomy. A lobe of the lung is removed
  • Pneumonectomy: Surgery to remove one whole lung.
  • Sleeve resection: Surgery to remove part of the bronchus.

Surgical management of lung cancer requires scientific pre-optimization involving quitting of smoking, improvement of general strength, cardiopulmonary reserve with respiratory spirometric exercises, brisk walking, and building up of nutritional status.

Lung surgeries are major procedures involving exhaustive preoperative, postoperative monitoring,intensive care and may have associated complications.

There are two major surgical approaches to treat lung cancer.

  • Thoracotomyis a surgery for the treatment and diagnosis of lung cancer that requires a large incision between the ribs and chest, as well as spreading of the ribs to allow optimal access to the lungs.This procedure would be described as the more traditional open surgery, serving as the only surgical option to treat lung cancer until more advanced techniques were popularized in the 1990s.
  • Minimallyinvasive surgery in contrastis accomplished with advanced instruments that are inserted through one or more small incisions and maneuvered to the problem site. In general, minimally invasive lung surgery is performed through a procedure called Video Assisted Thoracic Surgery (VATS). It has the advantages of decreased postoperative pain and hospital stay.

After surgery

Most patients can breathe normally after their surgery, but you can have a physiotherapist help you practice breathing and coughing.Most patients experience pain after the operation and receive medicine to alleviate their discomfort. Most patients are hospitalized for a week after surgery.

Most people need one or two months of convalescence following lung surgery. Quitting smoking is strongly advocated.


Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated. There are number of regimes available with different drugs and administration schedules depending on the patient’s general condition, type and the stage of cancer.

Radiation therapy

Radiation therapy is a treatment using high-energy rays or particles to destroy cancer cells. This treatment may be used to kill any cancer cells that remain in the lung area after surgery or chemotherapy. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapyuses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.The way the radiation therapy is given depends on the type and stage of the cancer being treated. It also depends on where the cancer is found.

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to attack specific cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do. Monoclonal antibodies and small-molecule tyrosine kinase inhibitors are the two main types of targeted therapy being used in the treatment of non-small cell lung cancer.


After your treatments are complete, you will be followed by your doctor at the hospital for a number of years, will be evaluated and investigated accordingly.  You can talk with your doctor if you have symptoms such as coughing, shortness of breath, pains, difficulty in swallowing or significant weight loss. In most instances you will be able to receive medication to treat the problem.

If you need advice regarding diet and lifestyle and assistive devices your doctor can inform you as to where you may get help.

Tips for Quitting Cigarettes

Smoking is probably one of the hardest addictions to overcome. For many people, it may take six to eight attempts before succeed­ing. Usually, people who stop smoking for at least three months are able to remain smoke-free for the rest of their lives. Helpful tips for quitting include:

Get ready. Select a quit day and make it special. Reduce usage before your quit day or switch to a brand you find distasteful and low in tar and nicotine.

Get support. Ask family and friends to help you quit by encouraging your efforts and by not smoking around you. Ask your doctor or employer for help in finding a smoking cessa­tion program.

Learn new skills and behaviours. Change daily routines to break away from tobacco triggers so that you’re not tempted. Avoid drinking alcohol, coffee and other beverages you as­sociate with smoking. Keep busy and active.

Consider nicotine replacement therapy. Try the nicotine patch or gum available at many drug stores. Studies have shown that using nicotine replacement with antidepressant medications may double your chances of quitting successfully and may help prevent or delay weight gain. Many of these medications require a physician prescription. Speak with your doctor about what aids are right for you.

       • Be prepared for relapse or difficult situations.

Comprehensive care

Lungcancer treatment is given by an expert multidisciplinary team which includesSurgical oncologists, Medical oncologists, Radiation oncologist, Pulmonologists, Pathologists, Intensivists, Physiotherapists, Dieticians, palliative care specialists.

*Disclaimer This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.