Breast cancer accounts for 30% of female cancers [1]. It is the most common cause of cancer-related death in females worldwide [2]. About 15% to 20% of breast cancers are human epidermal growth factor receptor 2(HER2) positive [2]. HER2 positive breast cancer confers an aggressive clinical phenotype including accelerated cell growth, high risk of systemic metastasis and recurrence [3].To improve treatment outcome of this aggressive breast cancer, patients are treated with doxorubicin-based chemotherapy followed by adjuvant trastuzumab which is monoclonal antibody directed against HER2 receptors [4]. Clinical trials showed that administration of trastuzumab sequential with doxorubicin was associated with high levels of cardiotoxicity as it interferes with homeostatic mechanisms and pathways of cell survival and repair, which exacerbates the damage induced by prior doxorubicin therapy [5]. Doxorubicin, as a member of anthracyclines, causes type 1 cardiotoxicity which is non-revesible, dose dependent and represented by structural cardiomyocyte alterations and cell death due to production of reactive oxygen species (ROS) which interacts with the myocardium and leads to imbalance between antioxidant mechanisms and pro-inflammatory substances [5, 6]. While doxorubicin increases the production of reactive oxygen and nitrogen species (ROS/RNS), blocking HER-2 signalling decreases activation of survival pathways and worsens oxidative and nitrative stress. This is the probable explanation for the additive cardiotoxic effect [7]. Trastuzumab causes type 2 cardiotoxicity as it inhibits signal transduction, neoangiogenesis and repair of DNA damage. Its cardiotoxicity is often reversible and doesn’t depend on the dose [5].

Many clinical variables predispose patients to this unfavorable adverse effect. Besides old age, history of cardiac dysfunction, diabetes and hypertension, racial and ethnic differences are known to affect incidence of cardiotoxicity in those patients [8, 9].

In oncological clinical practice, transthoracic echocardiography (ECHO) is the most often used diagnostic method for assessing cardiotoxicity as it is used for periodic evaluation of cardiac function and detects any changes in left ventricular ejection fraction (LVEF) [6].For early prediction of cardiotoxicity, serum levels of high sensitivity cardiac troponin I (hs-cTnI), Myeloperoxidase (MPO) and Interleukin-6 (IL-6) can be assessed [10,11,12].Multiple strategies are used to prevent chemotherapy-induced cardiotoxicity as reduction of the dose of chemotherapy or the use of cardioprotective drugs [6].Statins, including rosuvastatin, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, are widely used cholesterol lowering drugs. Rosuvastatin is believed to have antioxidant and anti-inflammatory effects that may help to prevent DNA damage and provide cardioprotective effect [13].

In this study, we investigate the possible protective effect of rosuvastatin in chemotherapy-induced cardiotoxicity in HER2 positive breast cancer patients.

Patients and methods

Our study was a prospective, randomized, controlled, parallel study conducted on 50 HER2 positive breast cancer patients that received doxorubicin followed by trastuzumab adjuvant therapy. The study was approved by The Research Ethics Committee of Tanta University and was carried out in compliance with the Declaration of Helsinki.All patients gave their written informed consents before participation. The study was retrospectively registered in Clinical Trials.gov and its ClinicalTrials.gov ID is NCT05338723. We used the CONSORT reporting guidelines [14].

Inclusion criteria

Female patients aged between 25 and 75 years old who were newly diagnosed with HER2 positive breast cancer and scheduled to receive doxorubicin followed by trastuzumab adjuvant therapy, with Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2, preserved left ventricular (LV) systolic function in which the left ventricular ejection fraction (LVEF) ≥ 50%,normal hematological, renal function and Alanine amino transferase (ALT) ≤ 3 times upper limit of normal (ULN) were included in the study.

Exclusion criteria

Pregnant or lactating females, those with ECOG performance status > 2, impaired LV systolic function in which LVEF < 50%, documented coronary artery disease, significant valvular heart disease, history of cardiomyopathy or congestive heart failure (CHF), ALT > 3 times ULN, Patients already taking statins or any other lipid lowering drug or with a known hypersensitivity to any of the used drugs were excluded from the study.

Patients’ selection and study design

All HER 2 positive breast cancer patients attending Clinical Oncology Department, Tanta University Hospital between October 2020 and October 2022 were tested for eligibility for our study, the total number was 60 patients, 7 patients were excluded (5 of them didn’t meet inclusion criteria and 2 patients refused participation), and 53 patients were recruited in the study, randomly divided into two groups based on days of admission: group 1 (control group) 26 patients didn’t receive rosuvastatin and group 2 (treatment group) 27 patients received 20 mg of oral rosuvastatin 24 h before the first cycle of chemotherapy and once daily for the rest of the follow-up period (6 months).

All patients received the same chemotherapy regimen: Doxorubicin 60 mg/m2 IV day 1 + Cyclophosphamide 600 mg/m2 IV day 1 cycled every 21 days for 4 cycles, followed by: Paclitaxel 80 mg/m2 by 1 h IV weekly for 12 weeks with Trastuzumab 4 mg/kg IV with first dose of paclitaxel followed by: Trastuzumab 2 mg/kg IV weekly.

One patient was missed from follow-up in group 1 and two patients were missed in group 2, the analyzed number was 25patients in each group (Fig. 1). All the patients were subjected to complete history taking, clinical examination, weight and height measurement, body surface area (BSA) calculation. The chemotherapy dose was calculated according to patients’BSA. For all patients, ECHO was done to detect changes in LVEF, and blood samples were collected to evaluate serum levels of High sensitivity cardiac troponin I (hs-cTnI), Myeloperoxidase (MPO) and Interleukin-6 (IL-6). Serum level of Alanine aminotransferase (ALT) was also assessed for patients in both groups to detect any significant side effects of rosuvastatin on patients’liver function.

Fig. 1

Consort flow diagram of the study

Echocardiography

Transthoracic echocardiography (Echo) was done for all patients 24 h before the initiation of drug therapy, after 3 months and after 6 months. Cardiotoxicity was defined as symptomatic heart failure or a decrease of left ventricular ejection fraction by ≥ 10% compared to the baseline value or to < 50% [6, 15].

Sample collection

For every patient, 5 ml of blood were drawn at plain tubes at the baseline (24 h before initiation of drug therapy), after 3 months and after 6 months. To extract serum, blood samples were allowed to clot, and then centrifuged. Each serum sample was divided to four portions to assess serum levels of hs-cTnI, MPO, IL-6 and ALT.

Laboratory methods

Enzyme‑linked immunosorbent assay (ELISA) was used for measurement of serum levels of hs-cTnI, MPO, IL-6 using the technique of double-antibody sandwich ELISA and was conducted according to the manufacturer’s instructions (Shanghai SunRed Biological Technology Co., Ltd, China). Spectrophotometric detection was used to detect the serum concentrations of ALT procedures were done according to the manufacturer’s instructions (Agappe Diagnostics Ltd., Ernakulam, Kerala, India).

Assessment of participants’adherence and side effects

Patients were regularly followed up through weekly calls and face-to-face meetings on three-weekly intervals at scheduled visits to evaluate their compliance with medication and to detect any reported side effects. The patients' adherence was assessed through counting the returned tablets and the rate of medication refills. Non-adherent patients were excluded from the study.

Primary and secondary outcomes of the study

The primary outcomes were the change in LVEF after 3 months and 6 months of treatment compared to baseline and the detection of incidence of cardiotoxicity in both groups. The secondary outcome was the change in serum levels of hs-cTnI, MPO, IL-6 after 3 months and 6 months of treatment compared to baseline.

Sample size calculation

G * Power 3.1 program was used to calculate the required sample size. Based on a previous study [16], the estimated sample size of 21 patients in each group would achieve a statistical power of 90% to detect the effect on the decline in LVEF (α error = 0.05, β error = 0.1). Assuming that the attrition rate is 15%, the sample size was 25 patients in each group.

Statistical analysis

Statistical analysis was done using Statistical Package for Social Sciences (IBM SPSS Statistics version 26). The Shapiro–Wilk test was used to examine the normality of the data, since showed the data are normal. Numerical variables expressed by mean and standard deviation. Repeated measure ANOVA test was used to compare durations for each group individually. Independent t-test was used to compare between the two studied groups through each duration. Chi square test was used for categorical variables. Correlation analysis was used to show the relation between LVEF & (hs-TnI, IL-6 and MPO) and hs-TnI & (IL-6 and MPO). P value < 0.05(*) was considered significant difference & P value < 0.001(**) was considered highly significant difference.