Neutrophil to lymphocyte ratio may be predict of mortality in all conditions.

Sir,

We read with great interest the article ‘A derived neutrophil to lymphocyte (N/L) ratio predicts clinical outcome in stage II and III colon cancer patients' by Absenger . They aimed to investigate the effect of the preoperative N/L ratio on time to recurrence and overall survival in patients with stage II and III colon cancer. They concluded that the N/L ratio is an independent prognostic marker in our study cohort including patients with stage II and III colon cancer. The ready availability of this parameter at no additional cost may encourage its wider use in clinical practice in the future. Thank to the authors for their contribution.

White blood cell (WBC) count is one of the useful inflammatory biomarkers in clinical practice. Although WBC is in normal range, subtypes of WBC like N/L ratio may predict cardiovascular mortality. N/L ratio is a readily measurable laboratory marker used to evaluate systemic inflammation (Balta ). Because hypertension, diabetes mellitus, metabolic syndrome (Balta ), left ventricular dysfunction, acute coronary syndromes, valvular heart disease, abnormal thyroid function tests, renal or hepatic dysfunction, known malignancy (Stotz ; Szkandera ), local or systemic infection, previous history of infection (<3 months), inflammatory diseases, and any medication that related to inflammatory condition of patients, the measurement of N/L ratio can be potentially affected in all of above conditions. For these reasons, it would be better, if the authors had mentioned these factors.

In conclusion, we strongly believe that these findings will elucidate further studies about N/L ratio as a surrogate marker of predicting mortality in colon cancer patients. Not only N/L ratio but also mean platelet volume, red cell distribution width (Demirkol ), platelet distribution width, CRP, uric acid (Cakar ) and gamma-glutamyl transferase (Cakar ) are easy markers to evaluate the prognosis of colon cancer patients (Demirkol ). However, one should keep in mind that N/L ratio itself alone without other inflammatory markers may not give exact information to clinicians about the prognosis of colon cancer patients. So, from that point of view we think that it should be evaluated accompanied with other serum inflammatory markers (Balta ).