Clinical Response and Safety of Letrozole-based Therapy in Postmenopausal Sudanese Women with Estrogen Receptor-positive/HER2-Negative Breast Cancer: A Retrospective Cohort Study
Lina Hassan Elobied
Department of Pharmacology, Faculty of Pharmacy, Omdurman Islamic University, Khartoum, Sudan.
Abdulbagi Elbadri Ali
Department of Pharmacology, Faculty of Pharmacy, Omdurman Islamic University, Khartoum, Sudan.
Mohamed Thabit Ahmed
Department of Pharmacology, Faculty of Pharmacy, Omdurman Islamic University, Khartoum, Sudan and Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
Kannan O. Ahmed
Department of Pharmacy Practice, College of Pharmacy, National University of Science and Technology, Muscat, Oman and Department of Clinical Pharmacy and Pharmacy Practice, Faculty of Pharmacy, University of Gezira, Wad Medani, Sudan.
Yasir S. Kheir
Department of Pathology and Microbiology, Ibn Sina National College for Medical Studies, Jeddah, Saudi Arabia.
Elmoiz Babekir
Department of Medicine and Adult Critical Care Medicine, Ibn Sina College for Medical Studies, Jeddah, Saudi Arabia and Department of Emergency Medicine, Faculty of Medicine, Mashreq University, Khartoum, Sudan.
Bashir A. Yousef
*
Department of Clinical Pharmacy and Pharmacology, Ibn Sina National College for Medical Studies, Jeddah, Saudi Arabia and Department of Pharmacology, Faculty of Pharmacy, University of Khartoum, Khartoum, Sudan.
*Author to whom correspondence should be addressed.
Abstract
Introduction: Estrogen receptor-positive/HER2-negative breast cancer is the most common molecular subtype of breast cancer. Aromatase inhibitors such as letrozole are part of the standard endocrine treatment regimen for postmenopausal patients; however, real-world evidence on patient outcomes from resource-limited African countries remains sparse. This study assessed the efficacy and safety of letrozole-based treatment regimens in postmenopausal Sudanese patients with ER-positive/HER2-negative breast cancer.
Methods: A retrospective cohort study was conducted among postmenopausal women at Khartoum Oncology Teaching Hospital, Sudan, between March 2018 and March 2020. Eligible participants were postmenopausal women with ER-positive/HER2-negative breast cancer who had received letrozole-based treatment regimens. Four groups were defined: docetaxel + letrozole, docetaxel + letrozole + radiotherapy, letrozole + radiotherapy, and mastectomy + letrozole. Data were collected from medical records, and the outcomes assessed included changes in tumour size, metastasis status, relapse, radiographic findings, and adverse effects. Descriptive and inferential non-parametric statistical analyses were performed using SPSS. Statistical significance was set at p < 0.05.
Results: Forty-six participants with a median age of 58.5 years (45–73) were included. Localised disease was present in 73.9% of participants, and T3 tumours accounted for 71.7%. Docetaxel + letrozole achieved complete tumour clearance in all 11 patients and produced a statistically significant reduction in tumour size (p = 0.001). Letrozole + radiotherapy reduced tumour size by 97.1% (p < 0.001), while mastectomy + letrozole resulted in complete absence of detectable tumour after surgery (p = 0.031). The metastatic multimodal group did not demonstrate statistically significant tumour control (p = 0.063). Overall, 37.0% of participants experienced relapse, predominantly among those with metastatic or T4 disease. Arthralgia was the most common adverse effect (26.1%), followed by hot flushes (23.9%).
Conclusion: Letrozole-based therapy showed favourable tumour responses in postmenopausal Sudanese women with localised hormone receptor-positive/HER2-negative breast cancer, particularly when combined with docetaxel, radiotherapy, or surgery. In contrast, metastatic disease was associated with a poor response and relapse despite combination therapy. Further studies are required to confirm these findings and evaluate survival outcomes.
Keywords: Breast cancer, letrozole, postmenopausal women, estrogen receptor-positive, relapse