Abstract

Examination of tumor biological factors for prognostic and predictive indicators is not part of routine testing in ovarian cancer. As in other tumors, the detection of hematogenous tumor spread could help to estimate the risk of metastatic disease. We examined the expression of p53, KI67, topoisomerase IIα (Top IIa), epidermal growth factor receptor (EGFR), human epithelial growth factor receptor 2 (HER2) and nm23 in tumor tissues from 90 patients with ovarian cancer. All underwent bone marrow (BM) aspiration and screening for disseminated tumor cells in the bone marrow (DTC-BM) at primary diagnosis. BM aspiration, cytospin preparation, and immunocytochemical staining with the anticytokeratin antibody (A45-B/B3) were done following a standardized protocol. The expression of p53, KI67, Top IIa, EGFR, HER2, and nm23 was evaluated by immunohistochemistry on paraffin-embedded tissue samples and classified by percentage of stained cells or immunoreactive score (IRS). The prognostic impact of the individual factors together with standard histologic parameters was calculated by univariate and multivariate analyses. Expression rates for HER2 (2+/3+: 34.5%), KI67 (median 30%), p53 (median IRS 5), and Top IIa (median IRS 4) were relatively high, whereas nm23 (median IRS 2) and EGFR (IRS 0: 61%) showed weak staining. In 21/90 patients (23.3%), DTC-BM (≥1/2 × 10⁶ cells) could be detected. The presence of DTC-BM was inversely related to nodal status (P= .015) but not to the other factors examined. Tumor stage (P= .02), lymph node involvement (P= .003), grade (P= .046), postoperative tumor residue (P <.001), peritoneal seeding (P= .02), and KI67 (P= .046) significantly correlated with overall survival (OS) after a median observation time of 28 months (2–105). The finding of ascites was borderline significant (P= .050). The presence of DTC-BM (P= .04) and KI67 positivity (P= .02) predicted reduced distant disease-free survival. By multivariate analysis, postoperative tumor residue remained an independent factor for OS (P= .02, relative risk = 4.6). As a primarily locoregional disease, tumor stage and postoperative tumor residue are the main determinants of prognosis in patients with ovarian cancer. However, even in advanced stages, examination of tumor biological factors could help to stratify subgroups of patients and establish targeted therapies.