Aim: This study aims to evaluate the prognostic and predictive value of plasma plasminogen activator inhibitor-1 (PAI-1) and endoglin in metastatic colorectal cancer (mCRC) patients receiving chemotherapy with bevacizumab.
Materials and methods: Between April 2012 and September 2013, 47 mCRC patients with a mean age of 58.5 ± 9.6 years were included in the study. Male-to-female ratio was 29/18. The baseline and posttreatment plasma PAI-1 and serum endoglin levels after 3 cycles of bevacizumab-containing chemotherapy were evaluated. The percent change between baseline and posttreatment levels after treatment was also recorded.
Results: The median follow-up duration was 26.6 months (range 1.8-70.2 months). The clinical benefit rate was 70% (partial response [32%], stable disease [38%]). Overall survival was 20.8 ± 1.5 months. The patients with progressive disease had statistically significantly higher baseline PAI-1 level (57.9 pg/mL vs. 29.9 pg/mL, P = 0.036). The percent change of the plasma PAI-1 level after the third cycle of treatment was also statistically significantly lower in those with clinical benefit (P = 0.035). However, there was no statistically significant difference in endoglin level and its change after therapy with respect to the response to treatment (P = 0.771 and P = 0.776, respectively). Plasma PAI-1 level had no statistically significant effect on survival (P = 0.709).
Conclusion: Baseline plasma PAI-1 level and its percent change with bevacizumab were shown to have statistically significant predictive value for the response to therapy whereas serum endoglin had no statistically significant predictive value for the response to therapy. However, neither PAI-1 nor endoglin had prognostic significance in mCRC.
Keywords: Bevacizumab; colorectal cancer; endoglin; plasminogen activator inhibitor-1.