Reply: Comment on ‘A derived neutrophil to lymphocyte ratio predicts clinical outcome in stage II and III colon cancer patients'

We would like to thank Balta et al (2013) for their valuable comments and suggestions on our study ‘A derived neutrophil to lymphocyte ratio predicts clinical outcome in stage II and III colon cancer patients'. The results of our study show that the derived neutrophil to lymphocyte ratio (dNLR; absolute count of neutrophils divided by the absolute white cell count minus the absolute count of neutrophils) and the neutrophil to lymphocyte ratio (NLR) are independent prognostic markers for time to recurrence and overall survival in patients with stage II and III colon cancer (Absenger et al, 2013). In contrast to many other previously proposed biomarkers, the dNLR and NLR are relatively cheap and easily determinable laboratory parameters, which would allow a widespread clinical use.

Recent data indicate that inflammation plays a critical role in the pathogenesis and progression of cancer. Systemic inflammatory response to tumours causes changes in the haematological components. The dNLR and NLR have recently been shown to negatively influence the clinical outcome in various cancer entities, including kidney cancer, soft-tissue sarcoma, pancreatic cancer and colon cancer (Procter et al, 2012; Absenger et al, 2013; Stotz et al, 2013; Szkandera et al, 2013; Pichler et al, 2013a). In most studies including our study, however, major potential confounding factors, such as local or systemic infection, ischaemia, acute coronary syndrome, metabolic syndrome, diabetes mellitus and renal or hepatic dysfunction, that might affect the neutrophil and lymphocyte counts have not been taken into account (Tamhane et al, 2008; Azab et al, 2012; Buyukkaya et al, 2012; Biyik et al, 2013; Gary et al, 2013). As the preoperative white blood cell count was obtained within 3 days before surgery in our study, at least local or systemic infections or inflammatory diseases could be relatively reliable excluded. However, we absolutely agree with Balta et al (2013) that a combination of multiple serum inflammatory biomarkers such as dNLR, NLR, CRP, fibrinogen, platelet to lymphocyte ratio and all possible confounding factors should be included in further studies, preferentially in prospective trials (Shiu et al, 2008; Demirkol et al, 2013; Son et al, 2013; Pichler et al, 2013b).

The authors declare no conflict of interest.