CD133 protein expression in primary liver cancer; associated demographic and histopathological characteristics in Uganda

Abstract

Primary liver cancer is a leading cause of cancer morbidity and mortality. Globally, it is the 6th most common cancer and the 3rd most common cause of cancer deaths. In Uganda, liver cancer is the 7th most common cancer and 4th most common cause of cancer deaths. Despite recent advances in its treatment, resistance to chemotherapy and radiotherapy, relapse, and metastasis remain a challenge. Recent evidence has linked cancer stem cells (CSCs) with tumorigenicity, treatment resistance, relapse, and metastasis of several cancers including liver cancer. CSCs have been identified by several markers, CD133 protein being one of the most studied. There is no information characterizing CD133 protein expression in liver cancer in Uganda. Characterizing it will provide baseline information that will be used to stratify primary liver cancer patients based on its expression, and potentially improve prognostication and enable CD133 targeted therapy. Objective: This study sought to determine the prevalence of CD133 protein expression in primary liver cancer (PLC) and establish its association with age, sex, histological types, and grades in Uganda. Methods: A cross sectional laboratory-based study on archived formalin fixed paraffin embedded (FFPE) liver tissue blocks from patients histologically diagnosed with PLC at the departments of pathology of Makerere University Kampala (MUK), Mulago National Referral Hospital (MNRH), and Uganda Cancer Institute (UCI) from 2017 to 2022 were used, the sample size was 86, a semiquantitative technique to score CD133 protein expression was used, and data was analysed using STATA version 16. Results: The mean age of patients from which specimens were collected was 44years with standard deviation of 16years. Most of the patients were males, 55(64.0%). The majority, 42(48.8%) of the patient specimens were poorly differentiated. Most, 77(89.5%) had hepatocellular carcinoma. Of all the 86 cases, 76(88.4%) were positive for CD133 protein expression while 10(11.6%) were negative, 23(26.7%) had a high expression while 53(61.6%) had a low expression. Conclusion: The prevalence of CD133 protein expression in PLC in Uganda was 88.4%. CD133 protein expression reduced as histological grade increased. Sex, age, and histological type did not affect CD133 protein expression in PLC in Uganda.