You can get breast cancer at any time, including between your screening tests. We call cancers that are found in between screening tests, 'interval cancers'.
Interval cancer is not common
Interval cancers happen in every screening programme. They are unavoidable. But interval cancers are not common.
Interval cancers occur in around 2 in every 1,000 women screened. This is a low rate that compares well internationally.


Types of interval cancers
There are 3 types of interval cancer in breast screening.
- Newly detectable cancers that have developed since your last screening appointment.
- Cancers that were visible at the last screen but not recalled for further tests. This usually happens because the signs of cancer were very subtle and thought to be normal.
- Cancers that were visible at the last screen but not recalled for further tests. This usually happens because the signs were missed. This is rare.
Review your screening history after interval cancer diagnosis
Anyone diagnosed with breast cancer can request a review of their screening history.
We are updating our review process at the moment and will update this page with details when this process has been finalised.
Read an expert panel review of our interval cancer review process.
If you have any queries about interval cancers or the review process, you can contact your screening unit or you can contact:
- Freephone 1800 83 21 88 - Monday to Friday, 9am to 5pm
- info@breastcheck.ie