All UK patients who participated in the TARGIT-A Trial were initially treated for early breast cancer between 2000-2012. A total of 3451 patients from 33 hospitals in 11 countries participated in the trial and a comparison was made between traditional radiotherapy given over several weeks (external beam radiotherapy, EBRT) with TARGeted Intraoperative radioTherapy (TARGIT-IORT) as a single dose given during the operation to remove the breast cancer. The trial was funded by the Health Technology Assessment (HTA) programme of the Department of Health, UK and sponsored by University College London. The results from this trial have been published in major medical journals and have already started changing the way breast cancer in treated around the world; please see www.targit.org.uk for more details. We would like to continue to collect data about the health status of all patients to enable us to learn about longer term differences in the effects of these treatments on health. An analysis of this information could improve treatment for patients with breast cancer. For this, HTA have granted us further funding.

Inclusion Criteria:

• All patients who participated in the TARGIT-A trial (NCT00983684).

Exclusion Criteria:

• Any patient who has withdrawn consent for further follow-up, or died.

All patients who participated in the TARGIT-A trial (see NCT00983684).