The difference between complementary and alternative therapies (CAMs)

There is an important difference between a complementary therapy and an alternative therapy.

The phrases complementary therapy and alternative therapy are often used as if they mean the same thing. They may also be combined into one phrase – complementary and alternative therapies (CAMs).

A complementary therapy means you can use it alongside your conventional medical treatment. It may help you to feel better and cope better with your cancer and treatment.

An alternative therapy is generally used instead of conventional medical treatment.

All conventional cancer treatments, such as chemotherapy and radiotherapy, have to go through rigorous testing by law. This is to prove that they work. Most alternative therapies have not been through such testing. And there is no scientific evidence that they work. Some types of alternative therapy may not be completely safe. And could cause harmful side effects.

Talk to your cancer doctor, GP, or specialist nurse if you're considering using any complementary or alternative therapies. Some treatments may interact. Also let your complementary or alternative therapist know about your conventional cancer treatment.

What are complementary therapies?

Complementary therapies are used alongside conventional medical treatments prescribed by your doctor. They can help people with cancer to feel better and may improve your quality of life. They may also help you to cope better with symptoms. Symptoms may be caused by the cancer or side effects caused by cancer treatment.

A good complementary therapist won't claim that the therapy will cure your cancer. They will always encourage you to discuss any therapies with your cancer doctor or GP.

There are many different types of complementary therapy, including:

  • aromatherapy
  • acupuncture
  • herbal medicine
  • massage therapy
  • visualisation
  • yoga

Many health professionals are supportive of people with cancer using complementary therapies. There are some health professionals that have been reluctant for their patients to use them. This is usually because many therapies have not been scientifically tested in the same way as conventional treatments.

Research is looking into how well complementary therapies work for people with cancer. And there is some still in progress. But we need more to find out how best to use complementary therapies.

What are alternative therapies?

Alternative therapies are used instead of conventional medical treatment. People with cancer have various reasons for wanting to try alternative therapies.

There is no scientific or medical evidence to show that alternative therapies can cure cancer. Some alternative therapies are unsafe and can cause harmful side effects. Or they may interact with your conventional medical treatment. This could increase the risk of harmful side effects. Or may stop the conventional treatment working so well. Giving up your conventional cancer treatment could reduce your chance of curing or controlling your cancer.

Some alternative therapies sound promising but the claims are not supported by scientific evidence. And can give some people false hope.

Examples of alternative cancer therapies include:

  • laetrile
  • shark cartilage
  • Gerson therapy

Other terms used to describe CAM therapies

There are several different terms commonly used to describe complementary or alternative therapies. If you're not familiar with them, it can be confusing. You may see therapies described as:

Unconventional therapies
This generally means treatments that aren’t normally used by doctors to treat cancer. In other words, any treatment that is not thought of as part of conventional medicine.

CAM (Complementary and Alternative Medicine) 
CAM is a term which covers both complementary and alternative medical therapies.

Integrated healthcare or integrated medicine
These terms are generally used to describe the use of conventional medicine and complementary therapies together. The terms are commonly used in the USA but are becoming more widely used in the UK.

In cancer care, integrated medicine usually includes making sure that you have access to all the following:

  • conventional medical treatments
  • different types of complementary therapies such as massage, reflexology, relaxation, herbal medicine and acupuncture
  • counselling services and support groups
  • up to date information about your cancer and its treatment

Traditional medicine
Health professionals usually use the term traditional medicine to mean a therapy. Or a health practice that has developed over centuries within a particular culture. It's usually formed around a particular belief system.

This term can be confusing. Because in the western part of the world, conventional medicine could be considered a traditional medicine. But this term is not usually used in this way. It generally refers to therapies or treatments that developed in the eastern part of the world. Such as:  

  • Ayurvedic medicine
  • traditional Chinese Medicine
Last reviewed: 
04 Apr 2022
Next review due: 
04 Apr 2025
  • Oxford Textbook of Palliative Medicine (3rd edition)
    D Doyle, G Hanks, N Cherny and K Calman
    Oxford University Press, 2005

  • The use of complementary therapy by men with prostate cancer in the UK
    S Wilkinson and others
    European Journal of Cancer Care, 2008. Volume 17, Issue 5

  • Use of complementary and alternative medicine in cancer patients: a European survey
    A Molassiotis and others
    Annals of Oncology, 2005. Volume 16, Issue 4

  • Potential health risks of complementary alternative medicines in cancer patients
    U Werneke and others
    British Journal of Cancer, 2004. Volume 90, Issue 2

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