ESTRO 2020 Abstract Book

S335 ESTRO 2020

with colleagues. Basic steps are the understanding of: a) How talk works in general b) How talk works in your current interaction with someone c) How you can talk to achieve what you hope to, based on b)

n=123/176 (70%) endocrine therapy. Of the n=134/176 (76%) who received radiotherapy, predominantly a 50Gy/25 or 42.4Gy/16 fraction course, n=88/134 (66%) received tangential RT and n=46/134 (34%) regional nodal irradiation. Mean heart dose (pre-DIBH era) for the n=46 evaluable left-sided RT cases ranged from 0.63-6.8Gy (mean=2.5Gy). Patients undergoing RT had an increased risk of heart failure (p=0.004) and valvular heart disease (p=0.04). No significant relationship was found between chemotherapy, Trastuzumab and/or endocrine therapy exposure and the subsequent risk of CV sequelae. Conclusion A range of cardiovascular conditions were observed after adjuvant therapy for breast cancer. Radiotherapy was associated with an increased risk of cardiovascular sequelae. Cardiovascular health remains an important survivorship issue. PH-0596 Whole breast irradiation in comparison to endocrine therapy in early stage breast cancer J. Haussmann 1 , W. Budach 1 , S. Corradini 2 , B. Tamaskovics 1 , E. Boelke 1 , F. Djiepmo-Njanang 1 , K. Kammers 3 , C. Matuschek 1 1 University Hospital Düsseldorf, Radiation Oncology, Düsseldorf, Germany ; 2 Ludwig-Maximilians-University, Radiation Oncology, Munich, Germany ; 3 The Johns Hopkins University School of Medicine, Division of Biostatistics & Bioinformatics- Department of Oncology, Baltimore, USA Purpose or Objective Multiple randomized trials have established adjuvant endocrine therapy (ET) and whole breast irradiation (WBI) as the standard approach after breast conserving surgery (BCS) in early stage breast cancer. The omission of WBI has likewise been studied in multiple trials and resulted in reduced local control with maintained survival rates and has therefore been adapted as a treatment option in selected patients in several guidelines. Omitting ET instead of WBI might also be a valuable option as both treatments have distinctly different side effect profiles. However the clinical outcomes of BCS+ET vs. BCS+WBI have not been thoroughly analyzed. Material and Methods We performed a systematic literature review searching for randomized trials comparing BCS+ET vs. BCS+WBI in low risk breast cancer patients with publication dates after 2000. We excluded trials using any form of chemotherapy, regional nodal radiation and mastectomy. The meta- analysis was performed using a two step process. First, the published individual patient EBCTCG data (IPD) were used to allow a direct and indirect comparison for overall survival (OS) and breast cancer-specific survival (BCSS). Second, we extracted all available published event rates and the effect-sizes for OS, BCSS, local- (LR) and regional recurrences (RR), recurrence-free interval (RFI), disease- free survival (DFS), distant metastases-free interval (DMFI), contralateral breast cancer (CBC), second cancer other than breast cancer (SCNBC) and mastectomy-free interval (MFI) as investigated endpoints and compared them in a network meta-analysis. Statistical analysis was performed using the Microsoft Excel add-in MetaXL 5.3 utilizing the inverse variance heterogeneity model. Results We identified three studies including a direct a comparison of BCS+ET vs. BCS+WBI (n=1059) and nine studies randomizing overall 5786 patients additionally to BCS only and BCS+WBI+ET resulting in 4 arms. Using IPD OS and BCSS were not significantly different between BCS+ET and

Poster Highlights: Poster highlights 19 CL : Breast

PH-0595 Cardiovascular sequelae after adjuvant therapy in a 10-year cohort of breast cancer patients. Z. LI 1 , A. Satchithanandha 1 , A. Hopkins 1,2 , J. Otton 1,2 , J. Descallar 1,3 , D. Adams 1,4 , S. Tang 1,5 , M. Field 1,6 , V. Batumalai 1,5 , L. Holloway 1,5,6,7,8 , G. Delaney 1,5 , E. Koh 1,5 1 University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia ; 2 Liverpool Hospital, Cardiology, Sydney, Australia ; 3 Ingham Institute of Applied Medical Research, Department of Biostatistics, Sydney, Australia ; 4 Macarthur Cancer Therapy Centre, Department of Medical Oncology, Sydney, Australia ; 5 Liverpool Hospital, Department of Radiation Oncology, Sydney, Australia ; 6 Ingham Institute of Applied Medical Research, Department of Medical Physics, Sydney, Australia ; 7 University of Wollongong, Centre of Medical Radiation Physics, Sydney, Australia ; 8 University of Sydney, Sydney Medical School, Sydney, Australia Purpose or Objective Cardiovascular (CV) sequelae after adjuvant therapy remains an important issue in breast cancer (BC) survivors. This study aimed to determine the impact of adjuvant therapy on CV sequelae in breast cancer patients. Material and Methods Patients diagnosed with Stage I-III breast cancer between 2006-2015 and treated with adjuvant therapy within South Western Sydney were retrospectively identified. Clinico- demographic and adjuvant treatment details including chemotherapy, Trastuzumab, endocrine therapy and radiotherapy were extracted from oncology records and matched with a cardiology database. Patients who developed a new or worsening pre-existing CV condition, coded as per ICD-10 classification, and categorised as at least moderate or severe on relevant investigations, were defined as ‘index’ cases. The time interval between breast cancer and CV condition were classified as ‘acute’ (0-6 months), ‘sub-acute’ (6-24 months) and ‘chronic’ (>24 months) respectively. Overall cohort and index group details were summarised descriptively. Fisher’s exact test was performed to compare and analyse the effect of cancer treatments on index versus non-index cases. Results Of 3608 patients, there were n=1522 Stage I, n=1526 Stage II and n=560 Stage III, aged 22-98 years (mean 59 years). A total of 1555 (43%) received chemotherapy, n=379 (11%) received Trastuzumab, n=2655 (74%) received radiotherapy (RT) and n=2605 (72%) endocrine therapy. There were n=176/3608 (5%) index cases comprising n=272 CV conditions, including n=30 (11%) pre-existing conditions which worsened post BC treatment. CV conditions included valvular heart disease (n=70/272), heart failure (n=62/272), ischaemic heart disease (n=61/272), arrhythmia (n=49/272), cardiomyopathy (n=10/272) and pericardial effusion (n=8/272). Of note, n=103/176 ‘index’ cases experienced multiple CV conditions. Of these, n=25/272 (9%) were classified as acute, n=79/272 (29%) as sub-acute and 148/272 (54%) as chronic. Half of the index cases had ≥2 CV risk factors with n=72/176 (41%) receiving chemotherapy, n=25/176 (14%) Trastuzumab and