Multi-drug resistance (MDR1 C3435T (rs1045642)) Gene Polymorphism and Its Association with Breast Cancer Risk and Chemotherapy Resistance in Sudanese Patients

Background: The global incidence of breast cancer has increased, and multidrug resistance (MDR1) has increased patient and healthcare burdens. This study investigated the relationship between MDR1 polymorphisms (C3435T) and chemotherapy resistance in Sudanese patients with breast cancer. Materials and Methods: In this case-control study, 70 patients with clinically diagnosed breast cancer were enrolled, along with 70 age-matched controls. Demographic and medical data were gathered, and MDR1 genotyping was conducted using the polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) technique. Results: Demographic data indicated that breast cancer was most prevalent among individuals aged 51–60 years, accounting for 52.3% of the cases, with an average age of 51.9 ± 11.5. Afro-Asiatic speakers comprised 52.7% of the population, and 56.2% were from Northern Sudan. A family history of the disease was reported in 32.9% of the cases, and 77.1% were diagnosed with invasive ductal carcinoma (IDC), with late-stage and high-grade tumors constituting 70% and 90% of the cases, respectively. Chi-square analysis demonstrated a significant association between the MDR1 gene mutation and an increased risk of breast cancer (OR = 5.46, P-value = 0.000), as well as a response to chemotherapy. Conclusion: The data suggest that the MDR1 C3435T polymorphism increases breast cancer risk in Sudanese women and is associated with chemotherapy resistance