Abstract 227P
Background
Trastuzumab increases survival in HER2 positive breast cancer patients. Cardiotoxicity is one of the main concerns, because its appearance causes delays or treatment suspension. The aim of this study was to identify the risk factors associated to the development of cardiotoxicity secondary to trastuzumab, and its clinical relevance in a cohort of HER2 positive breast cancer patients.
Methods
Retrospective study of HER-2 positive breast cancer patients treated in our center between 1995 and 2018. Cardiotoxicity was defined as a decline of more than 10% of the baseline left ventricular ejection fraction (LVEF) assessed by multigated acquisition scan (MUGA).
Results
239 patients were included in the analysis (mean age 57 ± 12 years). During a mean follow up of 71 months, 21 of them (8.8%) developed a decrease in the LVEF considered cardiotoxicity from which 3 (14.2%) suffered clinical heart failure. Baseline characteristics are summarized in table. Trastuzumab was discontinued in all patients of this group. LVEF recovered completely in 19 (90.5%) in a mean time of 8 months but trastuzumab was only reinitiated in 12 (60%) of them which completed the treatment. After multivariate analysis the body mass index (BMI) was the only cardiovascular risk factor associated to the development of cardiotoxicity (HR 1.17 CI95% 1.06-1.3; p=0.001). Cardiotoxicity was not associated with a lower survival during the follow up (log-rank=0.13). However, completion of trastuzumab was associated to a better outcome (log-rank =0.03, HR 0.37 CI95% 0.15-0.94, p=0.039). Table: 227P
Baseline characteristics
| Cardiotoxicity (n=21) | Without Cardiotoxicity (n=252) | p-value | |
| Age | 60.1 ± 11.1 | 57.0 ± 12.7 | 0.2857 |
| Hypertension (%) | 38.1 | 33.3 | 0.660 |
| Diabetes (%) | 4.8 | 7.5 | 1 |
| Dyslipemia (%) | 14.3 | 32.3 | 0.08 |
| BMI | 29.0 ± 4.9 | 25.7 ± 4.2 | 0.0007 |
| TNM I (%) | 28.6 | 30.1 | 0.864 |
| TNM II (%) | 42.9 | 34.3 | 0.864 |
| TNM III (%) | 28.6 | 34.7 | 0.864 |
Conclusions
In this cohort, BMI was related to the development of cardiotoxicity secondary to trastuzumab. The decrease in LVEF was not associated with worst prognosis and it was reversible in most of the patients. Due to the benefit of trastuzumab a more permissive treatment should be considered despite of the decline in LVEF.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.