Josef Hammer1, Hans Geinitz1, Carsten Nieder2, Christine Track3, Howard D Thames4, Dietmar H Seewald1, Andreas L Petzer5, Ruth Helfgott6, Kurt J Spiegl1, Dietmar Heck7, Elisabeth Bräutigam1. 1. Department of Radiation Oncology, Ordensklinikum Linz Barmherzige Schwestern, Linz, Austria. 2. Department of Oncology and Palliative Medicine, Nordland Hospital, Bodø, Norway; UiT - The Arctic University of Norway, Tromsø, Norway. Electronic address: cnied@hotmail.com. 3. Comprehensive Breast Health Center, Ordensklinikum Linz Barmherzige Schwestern, Linz, Austria. 4. Department of Biostatistics, University of Texas M.D. Anderson Cancer Center, Houston, TX. 5. Department of Internal Medicine - Hematology and Oncology, Ordensklinikum Linz Barmherzige Schwestern, Linz, Austria. 6. Comprehensive Breast Health Center, Ordensklinikum Linz Barmherzige Schwestern, Linz, Austria; Department of Surgery, Ordensklinikum Linz Barmherzige Schwestern, Linz, Austria. 7. Department of Surgery, Ordensklinikum Linz Barmherzige Schwestern, Linz, Austria.
Abstract
BACKGROUND: The purpose of this study was to analyze risk factors for ipsilateral in-breast relapse and inferior disease-free survival (DFS) after standard adjuvant whole-breast radiotherapy (± boost and systemic treatment) as part of a multimodal breast-conserving approach. PATIENTS AND METHODS: Decision trees were built through recursive partitioning analysis (RPA). The median follow-up for all 2161 patients was 114 months (9.5 years). RESULTS: Local relapse in the treated breast was uncommon (actuarial rates after 5 and 10 years were 2.7% and 5.8%, respectively). In RPA, the first split was related to age (52 years), with younger patients having a significantly higher risk of local relapse. The younger patients were stratified further by lymph node ratio (LNR). In patients older than 52 years, lack of endocrine treatment was associated with significantly higher risk. DFS was 80.7% at 10 years. The first split was caused by LNR, and the group with unfavorable LNR (> 0.20) could not be stratified further. Ten-year DFS in this group was as low as 50.6%. Patients with favorable LNR (0-0.20) could be stratified by additional risk factors, in particular primary tumor size. CONCLUSION: RPA is a suitable method to assign patients with early stage breast cancer to different risk groups, both regarding local relapse and DFS. Although age was a major risk factor for local relapse after breast-conserving management, LNR was associated with both endpoints. The systemic treatment approaches used in this study failed to provide satisfactory DFS in patients with LNR > 0.20 and 2 other subgroups.
BACKGROUND: The purpose of this study was to analyze risk factors for ipsilateral in-breast relapse and inferior disease-free survival (DFS) after standard adjuvant whole-breast radiotherapy (± boost and systemic treatment) as part of a multimodal breast-conserving approach. PATIENTS AND METHODS: Decision trees were built through recursive partitioning analysis (RPA). The median follow-up for all 2161 patients was 114 months (9.5 years). RESULTS: Local relapse in the treated breast was uncommon (actuarial rates after 5 and 10 years were 2.7% and 5.8%, respectively). In RPA, the first split was related to age (52 years), with younger patients having a significantly higher risk of local relapse. The younger patients were stratified further by lymph node ratio (LNR). In patients older than 52 years, lack of endocrine treatment was associated with significantly higher risk. DFS was 80.7% at 10 years. The first split was caused by LNR, and the group with unfavorable LNR (> 0.20) could not be stratified further. Ten-year DFS in this group was as low as 50.6%. Patients with favorable LNR (0-0.20) could be stratified by additional risk factors, in particular primary tumor size. CONCLUSION: RPA is a suitable method to assign patients with early stage breast cancer to different risk groups, both regarding local relapse and DFS. Although age was a major risk factor for local relapse after breast-conserving management, LNR was associated with both endpoints. The systemic treatment approaches used in this study failed to provide satisfactory DFS in patients with LNR > 0.20 and 2 other subgroups.
Authors: Paula Dhiman; Jie Ma; Constanza L Andaur Navarro; Benjamin Speich; Garrett Bullock; Johanna A A Damen; Lotty Hooft; Shona Kirtley; Richard D Riley; Ben Van Calster; Karel G M Moons; Gary S Collins Journal: BMC Med Res Methodol Date: 2022-04-08 Impact factor: 4.615