Elevated serum insulin-like growth factor binding protein-2 as a prognostic marker in patients with ovarian cancer

The purpose of this research was to examine the diagnostic and prognostic significance of elevated serum insulin-like growth factor binding protein (IGFBP)-2 levels in women with ovarian cancer from diagnosis through treatment to relapse or remission.

Serum collected pre- and postoperatively in women newly diagnosed with ovarian cancer, during adjuvant chemotherapy cycles, at 6 months follow-up and at relapse was analyzed for IGFBP-2. Control serum was from women undergoing pelvic or abdominal surgery for benign ovarian disease or nonovarian pathology.

IGFBP-2 at diagnosis was significantly elevated (P < 0.0001) in women with ovarian cancer (887 +/- 62 ng/ml) compared with benign controls (337 +/- 25 ng/ml), and women undergoing nonovarian surgery (439 +/- 49 ng/ml) and correlated positively with tumor stage and cellular differentiation but not with CA125. Unexpectedly, IGFBP-2 levels increased additionally 1-week postoperatively in ovarian cancer patients (1581 +/- 90 ng/ml; P = 0.0027) as well as controls (977 +/- 95 ng/ml; P < 0.0001) and was higher in women who had suboptimal debulking compared with optimal debulking of their tumor. IGFBP-2 levels returned to normal in women without evidence of progressive disease, but remained significantly elevated in women who later relapsed. Patients with IGFBP-2 levels in the highest tertile at diagnosis had a significantly shorter progression-free interval and overall survival.

In ovarian cancer IGFBP-2 is elevated at diagnosis, and corresponds to stage and histology with patients in the highest tertile of IGFBP-2 more likely to relapse and have a poorer outlook. Identification of these patients at diagnosis may allow more individualized, aggressive adjuvant treatment and follow-up, and IGFBP-2 may therefore be an important additional prognostic marker in this disease.