A randomised phase III trial of adjuvant radiation therapy versus observation following breast conserving surgery and endocrine therapy in patients with molecularly characterised luminal A early breast cancer (BCT 2102: TUGETHER).

THIS DATASET IS NOT YET AVAILABLE FOR SHARING. Dataset of 31 participants, male or female >= 18 years with HER2 positive unresectable loco-regional or metastatic breast cancer. PD-L1 and TILs status recorded at pre-registration. Participants receive tucatinib 300mg Day 1-21 of each 21 day cycle + Pembrolizumab 200mg Day 1 of each 21 day cycle + Trastuzumab 6mg/kg Day 1 of each 21 day cycle. Treatment continues until disease progression or unacceptable toxicity. Participants who stop treatment for reasons other than progressive disease/new anti-cancer therapy will have clinical follow up visits every 6 weeks for 24 weeks, then every 9 weeks. Participants who stop treatment due to progressive disease due to progressive disease /new anti-cancer therapy will have Survival Follow Up every 4 months. The primary endpoint is objective response rate per RECIST 1.1 in the PD-L1 positive cohort, as devined by the 22C3 pharmDx PD-L1 assay of immune cell positivity of >= 10. Cancer Australia demographic data has been collected including: Year of birth, Postcode of home of address, Indigenous status, CALD status (Country of Birth, Main language other than English used as the principle means of communication).