Everything you should know about lung cancer

Lung cancer is one of the most common types of cancer, with 45,000 people in the UK diagnosed every year.

lung cancer
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Lung cancer is the third most common form of cancer in the UK, which is why it is important to know the signs and symptoms of lung cancer. More than 45,000 new cases are diagnosed every year, making it the most common cause of cancer death in the UK. While the rates are thought to be falling slowly, they remain high.

Lung cancer often starts out with symptoms that mimic less serious conditions. They can include persistent cough, breathlessness, and unexplained fatigue. That's part of the reason why lung cancer is so deadly.

People who smoke are at greatest risk of lung cancer; risk increases the longer you've smoked.

Lung cancer symptoms

  • A persistent cough, or a change in a cough that has been present for a long time
  • Coughing up phlegm (sputum) with blood in it (haemoptysis). This can sometimes occur as an early warning sign of a cancer that may still be curable. Any person who coughs up blood should see their GP for advice urgently as lung cancer must be considered, particularly if the person is a smoker over the age of 40.
  • Breathlessness
  • Weight loss
  • Fatigue
  • Loss of appetite
  • Pain in the chest or shoulder

    Other less common symptoms include a hoarse voice, difficulty swallowing, swelling of the face caused by a blockage of a main blood vessel (superior vena cava obstruction), and swelling of lymph glands (nodes).



    Lung cancer causes

    Smoking

    Smoking is the biggest risk factor for lung cancer. Tobacco smoke is thought to be responsible for more than 85 per cent of lung cancer cases. Cigarette smoke is full of harmful, cancer-causing substances called carcinogens. Smoking damages tissues in the lungs, and breathing in smoke causes changes in the lung tissue.

    The risk of lung cancer increases with the number of cigarettes smoked each day. If you are a heavy smoker consuming more than 20 cigarettes a day, the risk of developing lung cancer rises to about 30 to 40 times higher than if you don't smoke.

    Tobacco smoke is thought to be responsible for more than 85% of lung cancer cases.

    The risk of lung cancer in an ex-smoker falls as the years pass after quitting but a large study in 2018 (part of the Framingham Heart Study) still found that 40 per cent of lung cancer occurred in people who had quit smoking more than 15 years before. The risk does however drop greatly every five years that passes and it is never too late to stop and make a huge difference to your potential future health.



    Exposure to secondhand smoke

    Even if you don't smoke yourself, you may breathe in carcinogens that damage your lungs if you spend time with people who are smoking.

    Exposure to radon gas

    Radon is an odorless, tasteless radioactive gas that is released when uranium, thorium, and radium decay in rocks and soil. Unsafe radon levels can accumulate in a building and are of different levels in different areas. It is something you can reduce within the home if affected and advice is on the ukradon.org site. The risks from radon exposure are greater in smokers or former smokers.

    Exposure to asbestos

    Asbestos used to be a common material used in building insulation. Exposure to asbestos can increase your risk of lung cancer (and other cancers).



    Lung cancer prevention

    It is thought that 79 per cent of lung cancer cases in the UK are preventable, and 72 per cent of UK cases are caused by smoking.

    Lung cancer can't be prevented, but you can minimise your risk with these steps:

    • Don't smoke. Quit smoking if you've already started.
    • Follow a healthy diet.
    • Exercise most days of the week.

      Lung cancer diagnosis

      If you're experiencing lung cancer symptoms, your doctor will examine you carefully, may first order a blood test to rule out other possible causes of those symptoms, such as an infection.

      If you don't have an infection, you may undergo one or a combination of these tests:

      Chest X-ray or CT scan

      Usually, the first investigation is a chest X-ray. If a lung tumour is present, it needs to be at least a centimetre in diameter to be detectable by an ordinary X-ray. CT scans reveal more information about a tumour and whether it has spread.



      PET-CT scan

      Your doctor may order a positron emission tomography (PET) scan if your first imaging tests indicate you have lung cancer. The PET scan shows where there are active cancer cells in your lungs.

      Biopsy

      Depending on the site of the cancer, a biopsy will be obtained either by bronchoscopy, EBUS or by a percutaneous (through the skin) needle biopsy.

      Bronchoscopy is direct inspection of the inside of the breathing tubes with a thin fibre-optic instrument using local anaesthetic and is the best test for tumours in the main bronchi (air passages) in the centre of the chest. Endobronchial ultrasound (EBUS) is like having a bronchoscopy, but with an ultrasound as well.

      Needle biopsy is better for cancers near the periphery of the lungs (i.e closer to the ribs than the centre of the chest), beyond the reach of the bronchoscope. Occasionally if it is difficult to get enough tissue this way the doctor may need to an open lung biopsy under general anaesthetic, in a similar way to mediastinoscopy. Or patients may need to have keyhole surgery (thoracoscopy) to get a biopsy sample.

      Usually, a sample of sputum – the material coughed up from the respiratory tract – will also be examined for cancer cells and this can avoid the need for biopsy.

      If patients have enlarged lymph nodes because of the cancer, sometimes doctors need to take a biopsy from the lymph nodes to help with diagnosis and staging information.



      Types of lung cancer

      There are three main types of lung cancer, based on their appearance when examined under the microscope by a pathologist:

      • Small cell carcinoma (About 12 per cent of lung cancers)
      • Squamous cell carcinoma (the most common type of lung cancer)
      • Adenocarcinoma.

        Mesothelioma is a rare type of cancer that affects the covering of the lung (pleura) and is often caused by exposure to asbestos.

        It's important to know which type of cancer a patient has because small cell cancers respond best to chemotherapy (anti-cancer medicines), whereas the other types (often referred to collectively as non-small cell cancer) are better treated with surgery or radiotherapy (X-ray treatment).

        It's important to know which type of cancer a patient has because small cell cancers respond best to chemotherapy.

        The pathologist therefore needs a small tissue sample (biopsy) to examine. This will confirm that the diagnosis of suspected cancer is definitely correct and show which type of cell is involved.

        Lung cancer treatment

        Once a diagnosis has been made, treatment is carefully planned by a multidisciplinary team consisting of various health professionals and specialists. They will discuss your case together in confidence to decide on the best plan of action, combining all of their expertise. Your course of treatment will depend on the type and stage of your cancer, your overall health, and your personal preferences.

        Surgery

        Surgery is often recommended when lung cancer is confined to the lungs. Your doctor may recommend that you undergo chemotherapy or radiation first to shrink the tumours.

        There are three types of lung cancer surgery:

        • Wedge resection or segmental resection: The portion of the lung that contains a tumor is removed, along with some healthy tissue. This treatment is suitable for only a small number of lung cancer patients for whom cancer is limited to one area of the lung.
        • Lobectomy: Large parts of the lung, called lobes, are removed.
        • Pneumonectomy: An entire lung is removed.

          Radiotherapy

          Radiotherapy uses high-powered beams to destroy cancer cells.

          Radiotherapy is either radical or palliative. Radical radiotherapy is used in selected patients with localised tumours which are inoperable, and involves using high doses of radiation to try to destroy the tumour.

          Chemotherapy

          Chemotherapy uses either intravenous or oral drugs to kill cancer cells. It is usually administered over several weeks, with breaks to allow for recovery time.

          Biological therapies

          In recent years several biological therapies have been introduced for some lung cancers. These are a type of drug treatment which work by blocking some of the chemical messages that control growth of the cancer cells, or by helping the immune system to target the cancer.

          Lung cancer outlook

          The outlook in lung cancer varies greatly, depending on the stage of the disease at diagnosis and the patient's general health, as well as the type of lung cancer. Those affected should talk to their medical team about how the statistics apply in their case.

          Overall, about 1 in 3 of those diagnosed with lung cancer in the UK will live for at least a year after diagnosis. Around 10 per cent of patients can expect to be cured – that is they will be alive five years after diagnosis with no evidence of the cancer having returned.

          Around 10% of lung cancer patients can expect to be cured.

          However, even when cure isn't possible all patients can benefit from palliative treatment which can improve the quality of the time they have left.

          The main improvement in the management of lung cancer in recent years relates to the palliative care services with an increased emphasis on symptom control and support to the family.

          Your GP practice and the hospital specialist team will work together to tailor your treatment specifically to your type of cancer and your individual needs.


          Last medically reviewed: 28-07-2020

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