Why isn’t screening recommended for some cancers?

Different types of cancers develop in unique ways.

There are more than 200 different types of cancer that can develop throughout the body, each with unique ways of behaving and growing. In Australia, regular screening is recommended for the early detection of many common types of cancer. Bowel cancer screening, breast cancer screening, and skin cancer screening are all commonly performed.

Although screening for these cancers has proven to be very effective, screening is not as successful for all cancer types.

With 1 in 2 Australians diagnosed with cancer before the age of 85, it’s never been more important to understand the types of cancer screening recommended in Australia and the benefits and risks.

Why is cancer screening performed?

Cancer screening tests are used to find cancers at an early stage before they have grown, spread or caused symptoms. Detecting cancers at this very early stage means that treatment is more likely to be effective.

Cancer screening tests may also have other benefits, such as reducing your anxiety about cancer and potentially detecting other health problems.

These programs are population-based cancer screening programs. This type of screening program is only recommended when there is good evidence that the screening test is likely to find cancer early before symptoms develop and when there is effective treatment for early stage cancer.

The tests offered through these programs are carefully chosen as there must be a positive benefit to risk ratio established before a population-based screening program can be implemented.

Depending on your personal situation and health needs, your doctor may recommend other types of cancer screening tests alongside a physical examination such as:

• PSA tests for prostate cancer

• Skin cancer checks

• Bowel screening tests, such as colonoscopy

• Blood tests

What is overscreening of cancer?

Overscreening refers to screening for cancer too regularly, screening in people who are not at increased risk of cancer or screening where there is no proven health benefit. Overscreening can potentially lead to overdiagnosis and overtreatment of early stage cancers. For example, cancer screening tests may sometimes find cancer that would never have caused problems if left undetected. In turn, this can cause unnecessary anxiety and invasive follow up tests that come with their own set of risks.

Why isn't screening recommended for some cancers?

Cancer screening is not recommended for all types of cancer. This is because:

• The cancer may grow so slowly that it would never cause problems or affect a person’s life expectancy

• The cancer may be so rare that the chance of it being found by screening is very low

• The cancer screening test may cause more harm than good

• There is no cancer screening test available

• Cancer screening is only recommended if the cancer:

• Is relatively common and treatment can improve the chance of successful treatment

• Grows relatively quickly and is likely to cause symptoms

• Can be found at an early stage

• Is likely to be successfully treated if diagnosed at an early stage

Screening after cancer treatment

Once cancer treatment has ended, your doctor may recommend a range of follow up tests including cancer “screening” (often referred to as surveillance or follow up) to check if your cancer has returned (or recurred).

Although the likelihood of some types of cancer recurring is becoming lower, there is a chance that cancer can come back months or years after treatment has finished.

Screening based on your risk of cancer

Typically, the cancer screening you receive will depend on your individual circumstances and cancer risk factors. If you have a known cancer risk factor, such as a family history of cancer, your doctor may recommend that you start cancer screening tests at a younger age or have more regular cancer screening tests. General risk factors for cancer include:

• Older age

• Lifestyle factors, such as being overweight or alcohol use

• A past history or family history of cancer

• Exposure to certain chemicals and carcinogens (such as tobacco or asbestos)

• Certain viruses, bacteria and parasites

• Exposure to radiation, including from the sun

Cancer screening is an important tool that helps many Australians receive an early diagnosis of cancer, improving their chance of successful treatment.

To ensure any cancer is detected as early as possible, we encourage you to talk to your doctor about which screening tests are right for you. Contact the experts at Icon for more information on early cancer diagnosis and treatment.

The content on the Icon Cancer Centre website is for informational purposes only and should not be considered medical advice. It is not a substitute for consultation with a qualified medical practitioner. For personalised medical guidance, please consult with your GP or another qualified healthcare provider.