Neutrophil-to-Lymphocyte Ratio in Prognosis of Gastric Cancer.

Dear Editor:

We have read with great interest the article 'Clinical Significance of Preoperative Inflammatory Parameters in Gastric Cancer Patients' by Lee et al.1 This study assessed the potential relationship between the severity of inflammation and prognosis in cancer patients. They showed that preoperative elevated neutrophil-to-lymphocyte (N/L) ratio could predict the advanced stage of gastric cancer (GC).

Routine peripheral blood counts may be useful in prognosis of many malignancy such as GC. A complete blood count is a routine examination method that gives us information about the patient's formed blood contents; the red and white cells, the platelets, the count and dimensions of subgroups of cells, and parameters like the red cell distibution width, platelet cell distibution width and mean platelet volume.2 White blood cell (WBC) count is one of the helpful 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.3 Because hypertension, diabetes mellitus, metabolic syndrome,4 left ventricular dysfunction, acute coronary syndromes, valvular heart disease, abnormal thyroid function tests, renal or hepatic dysfunction, known malignancy,5 previous history of local or systemic infection, 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, the N/L ratio levels may be affected by many conditions. N/L ratio itself alone without other overt inflammatory markers may not accurately provide information about the prognosis of the patient.6 So, the N/L ratio should be evaluated together with other inflammatory markers like mean platelet volume7 and red cell distribution width.8 We believe that these findings will guide further studies about mean platelet volume as a surrogate marker of early diagnosis in patients with GC.