The pretreatment albumin to globulin ratio predicts chemotherapeutic outcomes in patients with unresectable metastatic colorectal cancer

Background: The pretreatment albumin to globulin ratio (AGR) has been reported to correlate with the long-term survival in patients with various cancers. However, there are no reports regarding the correlation between the pretreatment AGR and chemotherapeutic outcomes in patients with unresectable metastatic colorectal cancer. The aim of this study was to evaluate the prognostic significance of the pretreatment AGR in patients with unresectable metastatic colorectal cancer. Methods: A total of 66 patients with unresectable metastatic colorectal cancer who underwent palliative chemotherapy for metastatic tumors were enrolled. The AGR was calculated as follows: Albumin/(Total protein - Albumin). Results: The median pretreatment AGR was 1.254 (range: 0.849-1.840). We set 1.25 as the cut-off value based on the receiver operating characteristic curve. Based on the cut-off value of 1.25, 34 patients were classified into the high-AGR group and 32 patients were classified into the low-AGR group. The high-AGR group had a significantly higher chemotherapeutic disease control rate (p = 0.040) and better progression-free survival (p = 0.0171) and overall survival (p = 0.0360) rates than the low-AGR group. According to a multivariate analysis of survival, the AGR was identified to be an independent prognostic factor for progression-free survival (Hazard Ratio: 2.662, 95% Confidence Interval: 1.085-6.631, p = 0.033) and overall survival (Hazard Ratio: 2.247, 95% Confidence Interval: 1.069-4.722, p = 0.033). Conclusions: The pretreatment AGR is a useful prognostic marker in patients with unresectable metastatic colorectal cancer who receive palliative chemotherapy.