Background:

Breast cancer is the most frequently diagnosed malignancy among women worldwide and a major cause of morbidity and mortality. Anthracycline-based chemotherapy, particularly doxorubicin, remains a cornerstone of treatment; however, its clinical utility is limited by dose-dependent cardiotoxicity that can lead to irreversible cardiac dysfunction and heart failure. The search for effective cardioprotective interventions is therefore a key priority in cardio-oncology.

Aim:

This study aims to compare the efficacy of sodium-glucose cotransporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors in preventing doxorubicin-induced cardiotoxicity in Egyptian women with breast cancer.

Methods:

A prospective, randomized, controlled clinical trial will be conducted at Oncology Hospital of Tanta University. Eligible adult female patients with histologically confirmed breast cancer scheduled to receive anthracycline-containing chemotherapy will be randomized into three groups: (1) control (standard care), (2) SGLT2 inhibitor group (dapagliflozin 10-25 mg daily), and (3) DPP-4 inhibitor group (sitagliptin 50-100 mg daily). Treatment will start five days before the first chemotherapy cycle and continue for six months, with follow-up for an additional six months. Cardiac function will be assessed by echocardiography (LVEF and GLS) and biomarkers (Cardiac Troponin T, and NT-proBNP). The primary endpoint is the incidence of cardiotoxicity defined by a ≥10% decline in LVEF to <50% or a >15% relative decline in GLS accompanied by biomarker elevation.

Expected Outcomes:

It is anticipated that both SGLT2 and DPP-4 inhibitors will reduce the incidence and severity of doxorubicin-induced cardiotoxicity, with SGLT2 inhibitors expected to demonstrate superior cardioprotective efficacy. Findings from this study may support the integration of cardioprotective antidiabetic agents into oncology care pathways to improve the cardiac outcomes and overall survival of breast cancer patients.

Inclusion Criteria:

1. Female, ≥18 years, Egyptian nationality.
2. Breast cancer (any stage) with planned anthracycline containing chemotherapy (intended cumulative DOX ≥240 mg/m² or epirubicin ≥360 mg/m² equivalents).
3. Baseline echo suitable for LVEF ≥53%.
4. Able to consent and comply with follow up.

Exclusion Criteria:

• • Type 1 and type 2 diabetes; history of diabetic ketoacidosis; pregnancy/lactation.

  • Symptomatic HF, cardiomyopathy, significant valvular disease, prior anthracycline exposure.
  • Baseline hypotension (SBP <95 mmHg), recurrent UTIs/mycotic infections, active foot ulcer/critical limb ischemia.
  • Inflammatory diseases, liver and kidney diseases.
  • Autoimmune diseases.
  • Other type of malignancies or metastatic diseases.
  • Patients who exposed to surgery less than one month.
  • Concomitant dexrazoxane planned upfront (allowed only for rescue; documented).
  • Known hypersensitivity to study drugs.