Platelet to lymphocyte ratio as a novel prognostic tool for gallbladder carcinoma

To preliminarily investigate the prognostic significance of the platelet to lymphocyte ratio (PLR) in patients with gallbladder carcinoma (GBC).

Clinical data of 316 surgical GBC patients were analyzed retrospectively, and preoperative serum platelet and lymphocyte counts were used to calculate the PLR. The optimal cut-off value of the PLR for detecting death was determined by the receiver operating characteristic (ROC) curve. The primary outcome was overall survival, which was estimated by the Kaplan-Meier method. The log-rank test was used to compare the differences in survival. Then, we conducted multivariate Cox analysis to assess the independent effect of the PLR on the survival of GBC patients.

For the PLR, the area under the ROC curve was 0.620 (95%CI: 0.542-0.698, P = 0.040) in detecting death. The cut-off value for the PLR was determined to be 117.7, with 73.6% sensitivity and 53.2% specificity. The PLR was found to be significantly positively correlated with CA125 serum level, tumor-node-metastasis (TNM) stage, and tumor differentiation. Univariate analysis identified carcinoembryonic antigen (CEA), CA125 and CA199 levels, PLR, TNM stage, and the degree of differentiation as significant prognostic factors for GBC when they were expressed as binary data. Multivariate analysis showed that CA125 > 35 U/mL, CA199 > 39 U/mL, PLR ≥ 117.7, and TNM stage IV were independently associated with poor survival in GBC. When expressed as a continuous variable, the PLR was still an independent predictor for survival, with a hazard ratio of 1.018 (95%CI: 1.001-1.037 per 10-unit increase, P = 0.043).

The PLR could be used as a simple, inexpensive, and valuable tool for predicting the prognosis of GBC patients.