Delta Neutrophil Index and Neutrophil Lymphocyte Ratio in Differentiation of Thyroid Malignancy and Nodular Goiter

Material-Methods Patients over the age of 18 who underwent thyroid surgery and who were operated on non-malignant benign causes (inguinal hernia) under selective conditions without any thyroid disease between November 2014 and November 2019 in Kahramanmaraş Sütçü İmam University Department of General Surgery were evaluated in this retrospective case-control cohort study. Patients in the thyroid pathology group (Group T) were divided into two subgroups according to their pathologic results: malignant (Group M) and benign thyroid disorders (Group B). Patients operated for inguinal hernia, were selected as control group (Group C).

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Preoperative biopsy results of patients undergoing FNAB in the preoperative period were investigated according to the Bethesda Classification System [11]. Neutrophil - lymphocyte count in the routine complete blood count (CBC) values, which were measured in the preoperative period and the postoperative sixth-month follow-ups, were recorded retrospectively and calculated manually. DNI (IG percentage) and IG counts were recorded from the values measured automatically in the CBC performed in the preoperative period and the postoperative sixth-month. Patient data were obtained from patient epicrisis forms and preoperative laboratory and postoperative pathology results recorded in the computer system.

Statistical Analysis The power analysis of the study was conducted with G-Power 3.0.10 programming system. Estimated power analysis and the sample size with an 0.8 power and effect size 0.1 according to three groups evaluation for 2 repeated measures in need of total 246 samples.

Statistical analysis was performed using IBM Social Package for the Social Sciences (SPSS) version 20 software. In the evaluation of independent groups, Kolmogorov-Smirnov and Shapiro-Wilk tests were used to determine if the distrubiton of variables were normal or not. Student t-test or Mann-Whitney U test was used to evaluate the numerical data between Group C and Group T. ANOVA or Kruskal Wallis test was used to evaluate numerical data for subgroup relations with Group C. Chi-square test or Fischer's exact test was used to evaluate categorical data. The repeated-measures ANOVA was used to evaluate the differences between the preoperative and postoperative periods. The data were evaluated using Posthoc Tukey's B test following the variance analysis. Sensitivity and specificity values and cut-off values were obtained via the receiver operating characteristic (ROC) analysis to evaluate the effectiveness of NLR, IG count, and DNI.