Breast cancer

In the framework of this workpackage, the following clinical trials are either ongoing or planned.

The DBCG RT Skagen trial 1 - NCT02384733

RCT offered to BC pts treated with loco-regional RT, and was a randomisation 50 Gy/25 vs 40 Gy/15 fr (boost is simultaneous). Primary endpoint is arm lymph edema. Patients from 7 countries including from all Danish depts. participate. Accrual ended July 2021 with 2963 pts, and based on the initial results, 40Gy/15fr became the new DBCG standard for locoregional RT of BC. Pts are in follow up for 10 years.

The DBCG RT Senomac trial 

RCT offered to cN0 BC pts, where SN reveals 1-2 macromets. Randomisation was ALND vs no ALND. Pts not having ALND receive level 1 RT. Primary endpoint is distant failure. Pts can be included in Skagen Trial also. Accrual ended Jan 2022 with 2766 pts, including 1000 pts from DK.

The DBCG RT Recon trial 

RCT offered to BC pts who are candidates for mastectomy and loco-regional RT. Randomisation is immediate vs delayed-immediate reconstruction in relation to timing of RT. Primary endpoint is any complication after reconstruction where a surgical intervention is needed. RT planning is based on the ESTRO consensus for target volume definition following implant-based reconstruction. The trial started Jan 2020, and per June 2023 it turned into a single-arm prospective cohort study due to poor accrual. The study ends accrual per Jan 2025. A phd study from Rigshospitalet is planned to report results from the trial.

The DBCG RT Natural trial - NCT03646955

RCT offered to highly selected BC pts (>=60 yr, pT1, pN0, non-lobular, grade 1-2, ER>10%, HER2-, margin >=2mm). Randomisation is PBI vs no PBI. Primary endpoint is 5 yr local recurrence.  All enrolled pts will be offered yearly screen mammography independent of randomisation arm. Based on results from a planned interim analysis, the study was put on hold per Nov 17, 2023. The decision to either re-open or close the trial is pending.

The DBCG RT DCIS study 

The gain and risk from RT of DCIS has never been reported in Danish pts. Thus, the recurrence pattern in DCIS pts treated with RT 2008-2017 is currently being investigated as part of a phd study to further optimise RT of DCIS.

The DBCG RT Proton trial - NCT04291378

A RCT testing proton versus photon RT in selected BC pts. Inclusion criteria are a mean heart dose of 4Gy and/or a V17 lung minimum 37% evaluated on a standard RT planning using tangential fields. If these criteria are fulfilled, the pts is invited for randomisation. The primary endpoint is 10-yr heart disease, and the most important secondary endpoint is distant failure. Target for accrual is 1502 pts.    

The DBCG RT Shared Decision study 

A generic tool for shared decision making (SDM) offered to BC pts who were candidates for adjuvant RT was developed, tested and validated in a prospective study. The aim was to introduce SDM to pts being offered RT through an evidence generating nationwide study. The trial changed the DBCG standard to recommend SDM to all pts treated with whole breast RT.

DBCG Hypo trial - NCT00909818

DBCG PBI trial - NCT00892814

Expected results

Based on these DBCG studies, the DBCG RT Committee wants to further develop and explore BC RT. The results will document morbidities and recurrences in modern treated BC pts receiving multimodal therapy. Most of the pts are expected to have no recurrence and few late side effects, but it will be possible to identify pts who suffer from moderate/severe late effects and hopefully offer them relevant therapies (or design future studies to explore treatment of the late effects). The results are expected to validate new target volume definitions, where smaller volumes are irradiated without increasing risks of recurrence. It may be possible to identify pts at high risk of late morbidity based on data from the RT plan, and potentially initiate preventive strategies.

Impact/Relevance/Ethics

The studies will be practice changing, and the results are expected to document that DBCG RT is "cutting edge". The projects have high clinical relevance and will apply with all ethical standards.