Purpose: To assess the levels of D-dimer baseline levels in inoperable metastatic colorectal cancer (mCRC) patients treated with bevacizumab and its relationship with prognosis.
Materials and methods: From June 1, 2011 to December 31, 2013, a total of 121 patients with mCRC received beacizumab combined with chemotherapy and 74 of them were included in the present study. A nonparametric statistical test was performed to analyze the relationship between plasma D-dimer levels and clinical pathological factors. The Cox proportional model was used to analyze the effects of D-dimer on progression-free survival (PFS) time and overall survival (OS).
Results: Of the 74 cases, 40 were men and 34 women (aged 31-74 years), with a median age of 55.5 years. The median of PFS and OS were 6.3 and 17.8 months respectively. High levels of baseline plasma D-dimer were correlated with high scoring of Eastern Cooperative Oncology Group-Performance Status (P = 0.001), IV phase of disease at the first visit (P = 0.001), unremoval primary focal (P = 0.006), the number of metastatic organs ≥ 2 (P = 0.034), abdominal cavity effusion (P = 0.004) and no history of adjuvant chemotherapy (P = 0.003). It was found by single factor analysis that plasma baseline D-dimer levels ≥ 1.9 μg/mL were closely related with a short PFS (hazard ratio [HR] 2.14, 95% confidence interval [CI] 1.04-4.40, P = 0.038) and OS (HR 5.22, 95% CI 2.05-13.28, P = 0.001). After adjustment for other factors, plasma baseline D-dimer levels ≥ 1.9 μg/mL were still closely correlated with a short OS (HR 3.52, 95% CI 1.28-9.67, P = 0.015).
Conclusion: High levels of plasma baseline D-dimer correlated with high tumor load, advanced disease status and poor prognosis of inoperable mCRC patients treated with bevacizumab. However, clinical research on a much larger cohort of patients will be required to verify these findings.