Platelet to lymphocyte ratio as a prognostic factor in patients with advanced colorectal cancer undergoing palliative treatment

Background: Our study aims to investigate the level of platelet to lymphocyte ratio (PLR) and determine its prognostic value in patients with advanced colorectal cancer undergoing palliative treatment. Methods: One hundred and fifty-two patients with advanced colorectal cancer confirmed in our hospital from January 2013 to January 2018 were selected as study participants. The boundary-value of PLR was determined by receiver operating characteristics (ROC) curves. Furthermore, the relationship between PLR and clinical characteristics of patients with advanced colorectal cancer was analyzed. Next, the prognostic factors affecting the survival time were analyzed by Kaplan-Meier single factor survival analysis and Cox multivariate regression model. Results: According to the ROC curve, the optimal critical value of PLR was 207.29. Patients were divided into high PLR (n=73) and low PLR (n=79) groups. The median survival time was 68.0 (24.5, 296.5) days for the high PLR group, and 124 (34, 438) days for the low PLR group and differences between the groups were statistically significant (P<0.05). Both groups had similar demographic features, namely gender, age, Eastern Cooperative Oncology Group (ECOG) score, and several metastasis sites (P>0.05). Albumin and hemoglobin levels were found to be negatively correlated to PLR (P<0.05). Cox multivariate regression model results showed that PLR, albumin, and ECOG score were independent prognostic factors (P<0.05). Conclusions: This study demonstrated that PLR is an independent prognostic factor of survival time, with good predictive value, in patients with advanced colorectal cancer undergoing palliative treatment. High PLR was significantly correlated to reduced survival rates, while low PLR was associated with better longterm survival rates.