Inflammatory biomarkers in metastatic colorectal cancer: prognostic and predictive role beyond the first line setting

Introduction: Inflammatory biomarkers are useful prognostic tools in cancer patients. However, the prognostic and predictive value of inflammatory biomarkers beyond the 1^st-line setting in metastatic colorectal cancer (mCRC) is unclear.

Results: In multivariate analysis 1 standard deviation increase in neutrophil-lymphocyte-ratio (NLR) was associated with an 8.5% absolute lower objective-response-rate (ORR) in 1^st-line (p<0.0001), 3% lower ORR in 2^nd-line (p< 0.0001), and 3% lower ORR in 3^rd-line (p=0.24), respectively. Regarding progression free survival (PFS), an increase in the NLR was significantly associated with rising hazard-ratios (HR) over all treatment lines (HR=1.30, p= 0.021 1^st-line); (HR=1.37, p<0.0001 2^nd-line); (HR=1.44, p=0.042 3^rd-line). The platelet-lymphocyte-ratio (PLR) was associated with 6-month PFS over all three treatment lines. Higher C-reactive-protein (CRP) predicted for worse PFS in the first two chemotherapy lines and in best supportive care (BSC). (HR=1.49 (p<0.0001 1^st-line); HR=1.25 (p=0.007 2^nd-line); HR=1.09 (95%CI 0.81-1.48, p=0.552 3^rd-line and HR=1.43 (p= 0.002 in BSC)).

Methods: Two-hundred-fifty-eight patients with mCRC undergoing palliative chemo(immuno-)therapy were retrospectively included. Primary endpoints were 6-month PFS and ORR during 1st-line, 2nd-line, and 3rd-line treatment, and 6-month overall survival during BSC.

Conclusion: This study shows that inflammatory biomarkers are useful predictors of disease outcome and treatment response over several treatment lines in mCRC patients.