About lung cancer

About lung cancer

About lung cancer

The most common type of lung cancer is adenocarcinoma, which is a subset of NSCLC. SCLCs comprise about 15 per cent of lung cancer and are the most aggressive type.

NSCLC accounts for about 85 per cent of all lung cancer. Just over half of all NSCLC is adenocarcinoma and about 30 percent is squamous cell carcinoma. Each type of lung cancer has its own unique genomic profile and we are just starting to learn how to choose better treatments based on the concept of personalised medicine.

  • Risks
  • Symptoms
  • Diagnosis & Treatment

While cigarette smoking or passive exposure to tobacco smoke are the principal risk factors for developing lung cancer, there is also a worrying increase of cases in people who have never smoked, especially women.

Additional factors that are associated with an increased risk of developing lung cancer include:

  • Exposure to second-hand smoke
  • Exposure to asbestos
  • Family history
  • Personal history
  • Older age
  • Radiotherapy treatment to the chest
  • Exposure to air pollution
  • Exposure to radon
  • Exposure to other workplace substances, including radioactive ores (e.g. uranium), chromium compounds, nickel, arsenic, soot, tar or diesel fumes
  • Infection with HIV, the virus that causes AIDS.

There are few warning signs of lung cancer and by the time symptoms occur it is often too late to remove the tumour surgically. As the cancer invades the lung and surrounding tissues it may interfere with breathing and cause:

  • Pain
  • Swallowing difficulties
  • Vocal cord paralysis
  • Infection
  • Unexplained weight loss; or
  • Fatigue.

With advanced cancer that has spread (metastasised to the bones or brain) there may be severe pain, blurred vision or seizures.

There is no widely accepted screening test for lung cancer. In up to 25% of cases, lung cancer is first discovered on a routine chest X-ray or CT scan as a small solitary mass.

Significant improvements in surgery and staging techniques over the last 15 years offer the possibility of curative surgery for those with early stage NSCLC. Some patients will also be treated with chemotherapy or radiotherapy after surgery.

If the cancer is advanced but still hasn’t spread, patients who are fit enough receive intense chemotherapy and radiotherapy, however, fewer than 15% will be alive at five years.

With advanced NSCLC, if the tumour contains a mutation in the EGFR gene, patients can be given a ‘targeted therapy’ which blocks this mutant gene’s activity. However, the tumours almost always develop drug resistance and eventually patients will need chemotherapy. For advanced NSCLC patients without the EGFR mutation, there is only chemotherapy and/or radiotherapy. Overall survival for either group is still less than 5% at five years.

When SCLC is localised to the chest, patients who are considered fit enough receive aggressive chemotherapy and radiotherapy. Once SCLC has spread beyond the chest, there is only chemotherapy to try to make the patient more comfortable, and less than 1% will be alive at five years.

Despite advances with targeted therapies in the last decade, the prognosis for lung cancer remains very poor and there isn’t a lot of hope for patients or their families. As the treatments are often toxic and have severe side effects, patients need to give up work and will often need a lot of supportive care, a major impact on families and an enormous cost to society.

This content is provided for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. If you have any concerns or questions about your health, please consult a suitably qualified healthcare professional.