Tumor Forkhead Box Q1 Is Elevated, Correlates with Increased Tumor Size, International Federation of Gynecology and Obstetrics Stage but Worse Overall Survival in Epithelial Ovarian Cancer Patients

Background: Forkhead box Q1 (FOXQ1) regulates epithelial ovarian cancer (EOC) cell proliferation, migration, and invasion; however, its prognostic effect in EOC patients is unclear. This study assessed FOXQ1 expression in EOC patients by immunohistochemical (IHC) staining and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and to analyze its correlation with EOC patients' clinical features and prognosis. Materials and Methods: FOXQ1 protein level in tumor and adjacent tissues from 173 EOC patients who underwent resection was detected by IHC staining and further scored by a semiquantitative scoring method; meanwhile, FOXQ1 mRNA level in tumor and adjacent tissues from 105 out of 173 EOC patients (whose fresh-frozen tissues were available) was detected by RT-qPCR. Besides, EOC patients' clinical features and survival data were collected. Results: Both FOXQ1 protein (n = 173) and mRNA (n = 105) levels were increased in tumor tissues compared with adjacent tissues (both p < 0.001) in EOC patients. Meanwhile, tumor FOXQ1 protein level was positively correlated with tumor size (p = 0.005) and International Federation of Gynecology and Obstetrics (FIGO) stage (p = 0.037), while FOXQ1 tumor mRNA level was only positively correlated with tumor size (p = 0.015) in EOC patients; however, they were not correlated with other clinical features such as histological subtypes, tumor differentiation, peritoneal cytology, and so on (all p > 0.05). Moreover, FOXQ1 protein (p = 0.030) and mRNA (p = 0.011) levels in tumors were both correlated with worse overall survival (OS) in EOC patients. Conclusion: FOXQ1 is elevated in tumor tissues, and its high tumor expression correlates with increased tumor size, elevated FIGO stage, and worse OS in EOC patients.