Open surgery induces a dramatic decrease in circulating intact IGFBP-3 in patients with colorectal cancer not seen with laparoscopic surgery.

Abstract

BACKGROUND: As shown earlier by the authors via Western blot analysis, open (OS) but not laparoscopic surgery (LS) induces a qualitative decrease in plasma insulin-like growth factor-binding protein 3 (IGFBP-3) levels on postoperative day 1 (POD 1). Intact IGFBP-3 has tumor suppressive effects, but its degradation products do not. Enzyme linked immunoassay (ELISA) inevitably measures both. In this study, using a novel combined Western blot and ELISA analysis method, precise plasma levels of intact IGFBP-3 on POD2 after open and closed colorectal cancer resection (stage I-III) were determined. METHODS: This study included 15 OS patients with a mean incision length of 26.7 +/- 15.5 cm and 16 LS patients with a mean incision length of 5.3 +/- 3.1 cm. Intact IGFBP-3 levels were determined via ELISA and Western blot analysis in plasma collected preoperatively and postoperatively. RESULTS: In the OS patients, the mean preoperative concentration of intact 43-45 kDa IGFBP-3 protein was 1920 +/- 1430 ng/ml. It decreased dramatically on POD2 to 355 +/- 545 ng/ml (p < 0.005). In the LS group, no significant difference was noted between the preoperative level (1305 +/- 807 ng/ml) and the POD2 level (922 + 714 ng/ml). CONCLUSIONS: Open cancer resection, unlike its minimally invasive alternative, induces a dramatic decrease in concentration of intact IGFBP-3, which may have important implications with regard to colon cancer recurrence.