PREOPERATIVE NEUTROPHIL-TO-LYMPHOCYTE RATIO AND AGGRESSIVE HISTOPATHOLOGIC FEATURES IN DIFFERENTIATED THYROID CANCER

Abstract

Background: Differentiated thyroid cancer (DTC) represents the majority of thyroid malignancies and generally has a favorable prognosis; however, a subgroup of patients develops aggressive pathological characteristics associated with increased recurrence risk and poorer clinical outcomes. Accurate identification of high-risk patients before surgery remains an important challenge in thyroid cancer management. The neutrophil-to-lymphocyte ratio (NLR), calculated from routine complete blood count parameters, has emerged as a potential indicator of systemic inflammation and tumor behavior. Previous studies have suggested that increased inflammatory responses may be associated with larger tumor size, metastatic potential, and unfavorable pathological features in thyroid cancer (Liu et al., 2016; Templeton et al., 2014).

Study type: Retrospective cohort study

Objective: This study aimed to evaluate the association between preoperative neutrophil-to-lymphocyte ratio and aggressive histopathological characteristics of differentiated thyroid cancer, including tumor size, capsular invasion, and lymph node involvement. Methods: A retrospective cohort study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan. Medical records of patients diagnosed with differentiated thyroid cancer who underwent thyroid surgery were reviewed. Preoperative complete blood count results were used to calculate NLR by dividing absolute neutrophil count by absolute lymphocyte count. Histopathological findings were collected from postoperative pathology reports. The relationship between NLR levels and aggressive tumor characteristics was analyzed using appropriate statistical methods. Results: Patients with higher preoperative NLR demonstrated a greater frequency of aggressive pathological features compared with patients with lower NLR values. Increased NLR was associated with larger tumor size, higher rates of capsular invasion, and increased lymph node involvement. These findings suggest that systemic inflammatory imbalance may reflect more aggressive tumor characteristics in differentiated thyroid cancer.

Conclusion: Preoperative neutrophil-to-lymphocyte ratio may represent a simple, cost-effective, and easily available biomarker for identifying patients with potentially aggressive differentiated thyroid cancer. Although NLR cannot replace established pathological and imaging-based assessment methods, it may provide additional information during preoperative risk evaluation, particularly in resource-limited healthcare settings. Further multicenter studies are required to establish standardized cutoff values and confirm its clinical utility.