Mammography most clearly reduces breast cancer mortality between ages 40 and 74; the Dutch national screening programme automatically invites women. The FIT colorectal cancer test for people aged 55 to 75 reduces colorectal cancer mortality with a well-considered balance between benefits and harms. Both screenings also have drawbacks such as false positives and overdiagnosis, and the effect on overall life expectancy is more modest than expected.
Two screenings that genuinely and demonstrably save lives are mammography (breast cancer) and the bowel cancer test. For breast cancer, a large 2024 analysis shows that regular mammography reduces the risk of dying from breast cancer, with the clearest benefit between roughly 40 and 74 years of age, once every one to two years. In the Netherlands you automatically receive an invitation through the national breast cancer screening programme once you fall within the target age group; outside that programme you can arrange it through your GP.
For bowel cancer the evidence is at least as strong. The Dutch national bowel cancer screening programme sends people aged 55 to 75 a stool test (FIT) at home, which is completely risk-free. An abnormal result is followed up with a colonoscopy. That colonoscopy carries small but real risks such as bleeding or perforation, so it is not a test you simply request outside a programme, but within the screening programme the balance has been carefully considered.
What both screenings have in common is that they clearly reduce the chance of dying from that specific cancer, but the effect on your overall life expectancy is more modest than the big picture might suggest. That does not diminish their value -- it puts it in perspective. And for both there are also downsides: false alarms and sometimes treatment of something that would never have caused symptoms. The starting age and the interval are therefore certainly worth discussing with your GP if you have specific risk factors, such as a family history.
If you are 45 or older and have not yet been invited for the bowel cancer screening, your GP is the right person to ask whether you already qualify.
Overview covering multiple factors (2 research records, 4 sources). The strength of evidence differs per component -- read the answer for the nuance.