Neutrophil-To-Lymphocyte Ratio is Associated With the Proportion of Poorly Differentiated Components in Papillary Thyroid Carcinoma

Introduction: Diagnosis of poorly differentiated thyroid cancer (PDTC) requires >= 50% of poorly differentiated components (PDC) in Japan. However, the optimal cutoff percentage of PDC for PDTC diagnosis remains controversial. Although high neutrophil-to-lymphocyte ratio (NLR) correlates with the aggressiveness of papillary thyroid cancer (PTC), whether NLR is associated with the proportion of PDC in PTC remains unstudied.Materials and methods: Patients with the pure PTC (n=664), PTC with < 50% PDC (n=19), or PTC with >= 50% PDC (n=26) who underwent surgery were retrospectively analyzed. Twelve-year disease-specific survival and preoperative NLR were compared among these groups. Results: Twenty seven patients died from thyroid cancer. The PTC with >= 50% PDC group (80.7%) showed significantly worse 12-year disease-specific survival than the pure PTC group (97.2%) (P < 0.001); however, the < 50% PDC group (94.7%) did not (P=0.91). The PTC with >= 50% PDC group had a significantly higher NLR than the pure PTC (P < 0.001) and the PTC with < 50% PDC groups (P < 0.001), whereas there was no significant difference in the NLR between the pure PTC and the PTC with < 50% PDC groups (P=0.48).Conclusions: PTC with >= 50% PDC is more aggressive than either pure PTC or PTC with < 50% PDC, and NLR potentially reflects the PDC proportion. These results support the validity of 50% PDC as a cut-off for PDTC diagnosis and indicate the utility of NLR as a biomarker for PDC proportion. (c) 2023 Elsevier Inc. All rights reserved.

Automated summary

Diagnosis of poorly differentiated thyroid cancer (PDTC) in Japan requires >= 50% of poorly differentiated components (PDC), but the optimal cutoff percentage of PDC remains controversial. This study found that PTC with >= 50% PDC is more aggressive than pure PTC or PTC with < 50% PDC, and NLR may reflect the PDC proportion.