The neutrophil to lymphocyte ratio can discriminate anaplastic thyroid cancer against poorly or well differentiated cancer

PURPOSE: We evaluated the capability of the neutrophil to lymphocyte ratio (NLR) as a diagnostic tool to discriminate between poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) from well differentiated thyroid cancer (WDTC). METHODS: The NLR of 3,870 patients with benign and malignant thyroid tumors were analyzed. There were 436 benign, 3,364 papillary, 15 medullary, 34 follicular or hurthle type, 14 PDTC, and 7 ATC type neoplasms. Patients were divided into two groups: a high NLR group and a low NLR group. RESULTS: The NLR of all 3,870 patients was a normal distribution, and the median value was 1.57. Advanced stage cancer, such as T3 or T4 was high (30.4% vs. 26.5%, P = 0.027), and cancer-specific deaths were also high (1.2% vs. 0.4%, P = 0.018) in the high NLR group. The proportion of PDTC (0.6% vs. 0.1%) and ATC (0.3% vs. 0.1%) was higher in the high NLR group. The NLR can discriminate between PTC, PDTC, and ATC (P = 0.035, P = 0.002, and P = 0.025, respectively), and the cutoff value was 3.8 between PDTC versus ATC. None of the NLR of PDTC exceeded the cutoff value of 3.8. CONCLUSION: NLR can play a relevant role as a discriminating tool and may be considered as a new diagnostic criterion in discriminating as well as in selecting therapeutic approaches to these aggressive forms of thyroid cancer.