Elevated FPR confers to radiochemoresistance and predicts clinical efficacy and outcome of metastatic colorectal cancer patients.

Association of chronic inflammation, primary tumor sidedness, adjuvant therapy and survival of metastatic colorectal cancer (mCRC) remains unclear. Circulating inflammatory cell, fibrinogen (Fib), albumin (Alb), pre-albumin (pAlb), Alb/Fib (AFR) and Fib/pAlb (FPR) were detected, and clinical outcome was obtained to determine the predictive, prognostic and monitoring roles of them in discovery and validation cohort. We found that elevated FPR, low AFR and poor survival was observed in right-sided mCRC comparing to the left-sided disease, elevated FPR harbored the highest areas under curve to independently predict poor progression-free survival and overall survival in overall and left-sided mCRC case in two cohorts. No survival difference was examined between the two-sided patients in subgroups stratified by FPR. Radiochemoresistance was observed in high FPR case. However, the patient could benefit from bevacizumab plus radiochemotherapy. Low FPR patient showed the best survival with treatment of palliative resection plus radiochemotherapy. Moreover, circulating FPR was significantly increased ahead imaging confirmed progression and it reached up to the highest value within three months before death. Additionally, c-indexes of the prognostic nomograms including FPR were significantly higher than those without it. These findings indicated that FPR was an effective and independent factor to predict progression, prognosis and to precisely identify the patient to receive optimal therapeutic regimen.