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ESTRO 2020

Session Item

Poster highlights 19 CL : Breast
8270
Poster Highlights
Clinical
10:30 - 10:38
Cardiovascular sequelae after adjuvant therapy in a 10-year cohort of breast cancer patients.
Zihan Li, Australia
PH-0595

Abstract

Cardiovascular sequelae after adjuvant therapy in a 10-year cohort of breast cancer patients.
Authors: Diana Adams.(Macarthur Cancer Therapy Centre, Department of Medical Oncology, Sydney, Australia), Diana Adams.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Vikneswary Batumalai.(Liverpool Hospital, Department of Radiation Oncology, Sydney, Australia), Vikneswary Batumalai.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Geoff Delaney.(Liverpool Hospital, Department of Radiation Oncology, Sydney, Australia), Geoff Delaney.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Joseph Descallar.(Ingham Institute of Applied Medical Research, Department of Biostatistics, Sydney, Australia), Joseph Descallar.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Matthew Field.(Ingham Institute of Applied Medical Research, Department of Medical Physics, Sydney, Australia), Matthew Field.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Lois Holloway.(Ingham Institute of Applied Medical Research, Department of Medical Physics, Sydney, Australia), Lois Holloway.(Liverpool Hospital, Department of Radiation Oncology, Sydney, Australia), Lois Holloway.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Lois Holloway.(University of Sydney, Sydney Medical School, Sydney, Australia), Lois Holloway.(University of Wollongong, Centre of Medical Radiation Physics, Sydney, Australia), Andrew Hopkins.(Liverpool Hospital, Cardiology, Sydney, Australia), Andrew Hopkins.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Eng-Siew Koh.(Liverpool Hospital, Department of Radiation Oncology, Sydney, Australia), Eng-Siew Koh.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Zihan LI.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), James Otton.(Liverpool Hospital, Cardiology, Sydney, Australia), James Otton.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Atiththa Satchithanandha.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia), Simon Tang.(Liverpool Hospital, Department of Radiation Oncology, Sydney, Australia), Simon Tang.(University of New South Wales, South Western Sydney Clinical School, Liverpool, Australia)
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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 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.