Is combination of neutrophil to lymphocyte ratio and platelet lymphocyte ratio a useful predictor of postoperative survival in patients with esophageal squamous cell carcinoma?

Dear editor

We read with interest the recent article entitled “Combination of neutrophil to lymphocyte ratio and platelet lymphocyte ratio is a useful predictor of postoperative survival in patients with esophageal squamous cell carcinoma” by Feng et al.1 In their study, authors aimed to investigate the usefulness of a novel inflammation-based prognostic system, using the combination of neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR), for predicting survival in patients with esophageal squamous cell carcinoma (ESCC). Finally, they concluded that combination of NLR and PLR is a useful predictor of postoperative survival in patients with ESCC and combination of these parameters is superior to NLR or PLR as a predictive factor in patients with ESCC. We would like to thank the authors for their contribution.

PLR has been recently suggested to be a marker of thrombotic and inflammatory condition, mainly in patients with malignancies.2,3 NLR is a readily available and inexpensive laboratory marker which is used to assess systemic inflammation. In literature, it was shown that diabetes mellitus, thyroid functional abnormalities, essential hypertension, valvular heart diseases, acute coronary syndromes, renal and/or hepatic failure, metabolic syndrome, and many inflammatory diseases may potentially affect the NLR.4–7 Thus, it would be more relevant if Feng et al had mentioned these NLR-affecting factors while evaluating the predictive role of NLR in postoperative survival of patients with ESCC. Besides, medication may alter NLR and/or PLR, so it would have been useful if the patients were described in greater detail in terms of antibiotic, anti-diabetic, anti-hypertensive drug use and/or other medications. In addition, it would also have been better if the authors indicated the elapsed time between taking the blood samples and measuring NLR and PLR, since waiting period prior to analysis may affect these parameters.

We believe that the findings of Feng et al1 will lead to further studies concerning the predictive role of NLR and PLR for postoperative survival of patients with ESCC. But, it should be clearly kept in mind that NLR or PLR itself alone without other variables may not secure true information about postoperative survival of patients with ESCC. Finally we concluded that these parameters should be evaluated with other variables as mentioned above.