Clinical trials are a research study that tests new and better ways of improving health in people. They are the final stage of a long and careful process that often starts many years earlier in the laboratory and are the link between scientific discoveries made in the laboratory and making new treatments available to people with cancer.

Clinical trials may be carried out to:

  • find out whether new and promising approaches to prevention, diagnosis and treatment are possible, safe and effective.  
  • look at ways of improving a person’s quality of life.

Types of trials

There are three different types of trials – treatment trials, prevention trials and screening trials.

Treatment trials

  • Test new treatments.  
  • The most common kind of trial.  
  • Treatments tested include:  
    • Drugs (such as chemotherapy), hormones and new drug combinations.  
    • Radiation therapy  
    • Surgical methods  
    • Supportive treatments (treatment against the effects of the cancer, not against the cancer itself)
  • Palliative care  
  • Ways to combine treatments  
  • New treatments like gene therapy, vaccines and antibodies  
  • Counselling and psychological support
  • Alternative therapies.

Prevention trials

  • Test new approaches – such as medicines, vitamins, minerals or other supplements, lifestyle changes (diet, physical activities) – that may lower the risk of getting cancer.  
  • Look for the best way to prevent cancer in people who have never had it, or to prevent second new cancers in people cured of their first cancer.

Screening trials

  • Test the best way to find cancer, especially in its earliest stages - examples include Pap smears, mammograms, x-rays and blood tests.

Why clinical trials are important

  • Clinical trials are the best way to improve the treatment and care of people who have cancer.  
  • Clinical trials give us essential information about the effects of different treatments – information that doctors and patients cannot find in any other way.  
  • They are how we discover if new treatments are more effective or have fewer side effects.  
  • The results of clinical trials today will improve treatment for people who develop cancer in the future. A new treatment can only become standard treatment if it is proven to be safe and effective in clinical trials.  
  • Many of the most effective treatments used today are the result of clinical trials done in the past 30 years.  
  • Clinical trials identify risks and side effects, which must be weighed up against the possible benefits of the new treatment.

Why do people enter trials?

  • In the hope that new treatments will be found that benefit people affected by cancer.  
  • To possibly get a new treatment that is not available outside the trial.

Reproduced with the kind permission of Cancer Council New South Wales.