Cancer stem cells with positive CD44 marker in advanced malignant epithelial ovarian tumors, and their relation with chemotherapeutic sensitivity Hassan Mansour Hegab a , Mahmoud S. Malis a , Bassma Mohamed El-Saaba b , Ahmed Samy El-Agwany a and Alaa Elzarka a Departments of a Obstetrics and Gynecology and b Pathology, El-Shatby Maternity University Hospital, Faculty of Medicine, Alexandria University, Alexandria, Egypt Correspondence to Ahmed Samy El-Agwany, PhD, Department of Obstetrics and Gynaecology, El-Shatby Maternity University Hospital beside Bibliotheca Alexandrina, El-Shatby, 21526 Alexandria, Egypt Tel: +20 122 825 4247; e-mail: ahmedsamyagwany@gmail.com Received 2 July 2015 Accepted 21 August 2015 Evidence Based Women’s Health Journal 2015, 5:175–179 Introduction Ovarian cancer is a highly lethal disease among all gynecologic malignancies and is the fifth leading cause of cancer-related deaths in women. Although the standard procedure is the combination of surgery and chemotherapy in patients with ovarian cancer, disease relapse commonly occurred due to the generation of chemoresistance. It has been reported that cancer stem cells are involved in drug resistance and cancer recurrence. Objective The aim of this study was to investigate the correlation between cancer stem cells with positive CD44 and response to conventional chemotherapy. Patients and methods The studied cases were 30 in number and all had been surgically debulked and received conventional chemotherapy for six cycles. They were divided as follows: the resistant group including 11 cases; the partially sensitive group including five cases; and the sensitive group including 14 cases. Results The rate of expression of CD44 antigen was significantly greater in the drug-resistant group (91%) than in the partially sensitive or the sensitive group (60 and 42.9%, respectively). Surgical staging, residual tumor size, tumor grade, and CA125 level were independent factors in chemotherapeutic resistance. Conclusion Overexpression of CD44 in epithelial ovarian cancer is a strong risk factor for resistance to conventional chemotherapy. Keywords: advanced malignant epithelial ovarian tumors, cancer stem cells, CD44 marker, chemotherapeutic sensitivity Evid Based Women Health J 5:175–179 & 2015 Evidence Based Women’s Health Journal 2090-7265 Introduction Ovarian cancer is considered the fifth leading cause of cancer-related deaths in women; the majority of cases are diagnosed in advanced stage [1]. Epithelial ovarian cancer is the most common histopathological type. It is more common in individuals in their 50s, those who are nulliparous obese, those of White race, and those with positive family history [2]. Advanced ovarian cancer cases are treated with initial surgical debulking for as much tumor tissues as possi- ble [3]. Postoperative chemotherapy is required for all cases [4]; platinum drug (cisplatin or carboplatin) plus paclitaxel for six cycles is considered conventional chemotherapy [4]. Evaluation of chemotherapy response was carried out by means of frequent follow-up of patients clinically, CA125 level and imaging study [5]. The most common challenge after chemotherapy is drug resistance or poor response [6]. The National Comprehensive Cancer Network (NCCN) has classified response to chemotherapy on the basis of chronological appearance of evidence of resistance: drug resistance, recurrence occurs before 6 months after comple- tion of chemotherapy; partial sensitivity, recurrence occurs after 6 months but before 12 months of chemotherapy; and drug sensitivity, no recurrence occurs at the end of 12 months [7,8]. Cancer stem cells (CSCs) are a subset of tumor cells that have the ability of self-renewal and proliferation forming the main bulk of tumor [9]. CSCs of ovarian cancer have surface markers called CD44, CD133, and CD24 [10]. Expression of CD44 surface marker is linked to cell migration and adhesion that may explain the aggressive nature of the tumor or resistance to chemotherapy [11]. CSCs also play role in tumor metastasis and tumor recurrence due to its antiapoptotic activity [12]. Devel- opment of resistance to chemotherapy in epithelial ovarian cancers involves multiple mechanisms. In recent Original article 175 2090-7265 & 2015 Evidence Based Women’s Health Journal DOI: 10.1097/01.EBX.0000471707.00703.95 Copyright r 2015 Evidence Based Women’s Health Journal. Unauthorized reproduction of this article is prohibited.