Platelet-to-Lymphocyte Ratio and Neutrophil-to-Lymphocyte Ratio Are Not Prognostic Biomarkers in Rectal Cancer Patients with Curative Resection.

BACKGROUND: Actual predictors of survival and recurrence for rectal cancer patients undergoing curative resection mostly come from pathological data of surgical specimen. Recently, novel blood biomarkers have been proposed as useful tools in cancer patient management, but few and conflicting data have been reported in rectal cancer. We evaluated the prognostic relevance of preoperative platelet-to-lymphocyte (P/L) ratio and neutrophil-to-lymphocyte (N/L) ratio on survival and recurrence in patients undergoing laparoscopic curative resection for rectal cancer.

METHODS: All consecutive patients who referred for primary rectal disease to the Department of General Surgery in Cittadella (Italy) from June 2005 to September 2015 were retrospectively evaluated. Patients with metastatic disease at surgery were excluded. P/L and N/L ratios were calculated. For patients undergoing neoadjuvant chemo-radiotherapy, pre-treatment data were considered. Follow-up data were updated at December 2016.

RESULTS: One hundred fifty-two patients were included in the study, 49 (32%) received neoadjuvant chemo-radiotherapy. Both P/L and N/L ratios showed poor discriminative performance on 5-year OS and DFS. Time-dependent ROC curves showed no improvements in discriminative performance of P/L and N/L ratios when considering different time endpoints. Multivariable analysis identified CEA-rather than P/L or N/L ratios-as independent predictor of OS and DFS, adjusting for age, tumor stage, and postoperative morbidity.

CONCLUSION: Neither P/L nor N/L ratios were associated with survival after rectal cancer surgery. Further studies on large series might provide insights on the role of these inexpensive blood biomarkers in rectal cancer.