Is nuclear expression of Y box-binding protein-1 a new prognostic factor in ovarian serous adenocarcinoma?

BACKGROUND. Nuclear expression of Y box-binding protein (YB-I), a member of the DNA binding protein family, has been reported to be much more highly c oncentrated in cisplatin-resistant cell lines than in their parental counte rparts, suggesting an ability to limit cisplatin sensitivity. Moreover, YB- 1 plays a key role in P-glycoprotein expression. Because ovarian carcinoma traditionally has been treated with cisplatin-based chemotherapy, the sensi tivity of the tumors to chemotherapy could reflect a particular prognosis i n patients with ovarian carcinoma. The aim of the current study was to dete rmine whether YB-I expression correlated with prognosis in ovarian serous a denocarcinoma patients. METHODS, The expression of YB-1 in the nucleus was examined immunohistochem ically in 42 paraffin embedded primary Stage III (International Federation of Gynecology and Obstetrics) serous ovarian carcinoma tumors extirpated by primary surgery at Kyushu University Hospital between 1985-1995. RESULTS. Of the 40 primary ovarian tumors examined, 12 (30%) were positive for YB-1 expression in the nucleus. There was no significant difference in intraperitoneal stage, histologic grade, or residual tumor size after prima ry surgery between patients with tumors with positive and those with negati ve nuclear expression of YB-1 protein. The disease free survival curve for patients whose tumors were positive for nuclear expression of YB-1 protein was significantly worse than that for patients whose tumors were negative ( P = 0.0025). P-glycoprotein was overexpressed in 4 of 12 tumors with nuclea r YB-1 expression (33%) but there was no statistical significance between t he expression of nuclear YB-1 and P-glycoprotein. CONCLUSIONS. The expression of YB-1 protein in the nucleus may be considere d a useful prognostic marker and also may reflect the sensitivity of ovaria n serous adenocarcinoma to chemotherapy. Cancer 1999;85:2450-4. (C) 1999 Am erican Cancer Society.