Neutrophil-to-Lymphocyte Ratio (NLR) for Preoperative Differentiation between Uterine Leiomyosarcoma (LMS) and Uterine Leiomyoma: A Case-Controlled Study

BACKGROUND: Differentiating uterine LMS from uterine leiomyoma is difficult. Therefore, this study aimed to compare preoperative NLR of uterine leiomyosarcoma (LMS) with leiomyoma and secondary objective aimed to identify the clinical characteristics to distinguish between uterine LMS and uterine leiomyoma including the appropriate NLR cut off value to differentiate LMS from leiomyoma. METHODS: This was a matched case-controlled study with 1:4 ratio. We collected data of patients with uterine LMS and leiomyoma from 2011 to 2020 at King Chulalongkorn Memorial Hospital. Patients with uterine LMS (case group) and leiomyoma (control group) were matched in terms of year of the surgery and size of the uterine mass. Statistical analysis was conducted using SPSS version 22.0 and STATA version 17. Conditional logistic regression analysis with a p-value of <0.05 was used. RESULTS: Twenty-seven patients who were diagnosed with uterine LMS met the inclusion criteria; 13 patients who had incomplete data and one patient who was had concurrent breast cancer were excluded. Thirteen patients were included in the final analysis. From 2,587 patients in control group; 52 patients were matched. The baseline characteristics in both groups were comparable except for menopausal status Women with uterine LMS had a higher NLR than those with leiomyoma (mean, 4.56 ± 2.5 and 2.4 ± 1.15 in the case and control groups, respectively). Conditional logistic regression determined that the NLR cut-off value of 2.8 was a statistically significant factor for determining uterine LMS (OR = 3.24; 95% CI 1.01–10.43). No significant difference was found in the other factors. CONCLUSIONS: Patients who were diagnosed with uterine LMS had a significantly higher NLR than those diagnosed with leiomyoma. The NLR is a simple and effective method for predicting the presence of a uterine LMS in patients who are pre-operatively diagnosed with a uterine mass.