Why isn't screening available for all cancers?Why isn't screening available for all cancers?
Screening programmes can only be set up for a particular cancer type if it will save lives from the disease without too much risk. The UK has 3 national screening programmes - bowel, breast and cervical, which have been shown to save lives.
A screening programme needs to have a good enough test for it to work. This test must:
- reliably detect any cancers or abnormal changes that could lead to cancer
- not cause too many false alarms
- be acceptable, so that people will actually take the test
- not be dangerous to health
- be cost-effective.
If a test doesn’t do these things, it’s unlikely to work well for screening the whole population.
If a cancer is rare, screening everyone wouldn’t work, and it would be harder for the benefits to outweigh the harms across everyone taking part. If good tests are available for rarer cancers, doctors will often offer them to people who are at highest risk of the disease.
If there isn’t a good enough test, or screening would do more harm overall to people taking part, then it isn’t introduced.
At the moment, there isn’t enough evidence to say that screening for any type of cancer other than breast, bowel, and cervical cancer would be a good idea.
But researchers are always looking for new tests and new ways to spot cancers early, and there are some types of cancer where research into screening is growing, for example, lung and ovarian cancers.
The PSA test for prostate cancer
There is no screening programme for prostate cancer because we don’t have a reliable enough test to use, and the test available at the moment has significant risks.
A test called the prostate specific antigen (PSA) test has been looked at to see if it could be used to screen for prostate cancer. But this test is not reliable enough to use for screening.
Overall, the evidence shows that screening for prostate cancer doesn’t reduce the number of men dying from the disease, but does increase the risk of harms such as overdiagnosis, where slow-growing tumours that wouldn’t cause a man any harm are picked up. It can also miss prostate cancers which did need to be found and treated.
If you’re over 50 you can ask your doctor about the prostate specific antigen (PSA) blood test. Having this test carries risk so if you ask for this test, your doctor will discuss it with you.
Research into screening for lung cancer
At the moment there is no national screening programme for lung cancer in the UK. But the NHS is offering Lung Health Checks in some areas of England
Find out more about NHS Lung Health Checks
There have been some trials looking at using CT scans to screen for lung cancer in people with a history of smoking. There is evidence that this type of screening could save lives from lung cancer. But it also looks like it will lead to some unnecessary tests, diagnoses and treatment, so the balance of benefit to harm isn’t fully clear yet.
A big European trial on lung screening was published at the beginning of 2020. We now need to understand more about how the results on the benefits and harms would translate to the UK population, so we can work out what a national lung screening programme might look like. We hope that the results of the trial will be reviewed by a government group quickly and thoroughly.
Read more about research into lung cancer screening
Research into screening for ovarian cancer
At the moment, there is no screening programme for ovarian cancer in the UK.
The trials to date haven’t been able to show that it would save lives from the disease. A UK trial is following women up for longer to be sure the results continue to hold true.
