Musashi-1 Expression is a Prognostic Factor in Ovarian Adenocarcinoma and Correlates with ALDH-1 Expression

The presence of cancer stem-like cells (CSCs) has been demonstrated to be associated with tumor metastasis, chemoresistance, and rapid recurrence of various tumors. The impact of CSC-related markers in the metastasis and prognosis of ovarian cancer has not been well established. In this study, the protein expression of musashi-1 and ALDH1 was measured using immunohistochemistry. Results demonstrated that the percentage of positive musashi-1 and ALDH1 expression were significantly higher in ovarian serous adenocarcinomas, mucinous adenocarcinomas and clear cell adenocarcinomas than in cystadenomas and normal tissues. The percentage of positive musashi-1 and ALDH1 expression were significantly lower in patients identified with clinical stage I or II ovarian adenocarcinomas without lymph node metastasis compared to patients with clinical stage III or IV tumors and lymph node metastasis. The expression of musashi-1 and ALDH1 was found to be highly consistent in ovarian adenocarcinomas. Univariate Kaplan-Meier analysis showed a negative correlation between musashi-1 or ALDH1 expression and overall survival. Multivariate Cox regression analysis showed that positive expression of musashi-1 or ALDH1 in ovarian adenocarcinoma was an independent predictor of poor prognosis. Our study suggested that musashi-1 and ALDH1 expression are closely related to metastasis of ovarian adenocarcinoma. The positive expression of musashi-1 and ALDH1 might be a poor-prognostic factor of ovarian adenocarcinoma.