Is the combination of neutrophil to lymphocyte and platelet to lymphocyte ratios a useful predictor of treatment response and prognosis in patients with non-small cell lung cancer?

Abstract

We read with interest the recent article entitled ‘Are neutrophil/lymphocyte and platelet/lymphocyte rates in patients with non small cell lung cancer associated with treatment response and prognosis?’ by Unal et al. (2013). In their study, the authors aimed to research effects of the pretreatment neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) on survival and chemoradiotherapy response in non-small-cell lung cancer patients (NSCLC). At the end of the study, they concluded that pretreatment NLR and PLR assessment may secure valuable prognostic results in patients with NSCLC. We would like to thank the authors for their contribution. PLR has been recently proposed to be a predictor of thrombotic and inflammatory conditions, principally in patients with many kind of malignancies (Smith et al., 2008; Wang et al., 2013). NLR is an inexpensive and easily available laboratory marker which is used to estimate systemic inflammatory status. To date, it has been shown that thyroid functional abnormalities, diabetes mellitus, essential hypertension, renal failure, metabolic syndrome, valvular heart diseases, many inflammatory diseases may potentially affect the NLR (Stotz et al., 2013; Zheng et al., 2013; Tanoglu et al., 2014, Tanoglu and Karagoz 2014). Thus, it would have been better if Unal et al. (2013) had mentioned these NLR-affecting factors while evaluating the pretreatment neutrophil to lymphocyte ratio on survival and chemoradiotherapy response in patients with non-small-cell lung cancer. Moreover, any kind of medication may easily change NLR and/or PLR, so it would have been more useful if the NSCLC patients were described in a detailed manner regarding antidiabetic drug, antihypertensive drug, antibiotic, steroid use and/or other medications. Besides, it would also have been more useful if the authors indicated the elapsed time between obtaining the blood samples and measuring NLR and PLR, since any time delay prior to analysis may affect these two parameters (Tanoglu et al., 2014, Tanoglu and Karagoz, 2014). We believe that the paper of Unal et al. (2013) will lead to further studies concerning effects of the pretreatment NLR and PLR on survival and chemoradiotherapy response in non-small-cell lung cancer patients. However, it should be clearly kept in mind that NLR or PLR itself alone without other variables may not provide accurate and