The purpose of this report is to use available data to estimate the overall risk and prevalence of distant metastatic disease in breast cancer patients. Metastases at diagnosis or subsequently are considered. Based on this, recommendations are made to improve the collection of progression and recurrence data for breast and other cancers.

The information presented is a description of the data extracted and collated from the NCRI databases to broadly describe metastatic breast cancer (MBC) pattern from 1994 to 2018 in Ireland, with particular reference to the years 2005-2018.

Findings are presented for:

• Metastatic site distribution
• The cumulative risk of developing distant metastases after diagnosis
• Overall risk of distant metastasis, at diagnosis or subsequently
• The cumulative risk of breast cancer deaths

The National Cancer Registry is funded by the Department of Health, and analyses for this report have been co-funded by the Irish Cancer Society.