Prognostic significance of neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios in solid tumors

Objective: The elevation of Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) has been associated with poor prognosis in patients with solid tumors in many adult studies. NLR and PLR have been demonstrated as auxiliary prognostic factors in cancer patients. These tests are advantageous due to their low cost and ease of calculation. However, there are limited studies showing the prognostic importance of NLR and PLR in childhood cancers in pediatric patients. With this study, we aimed to determine the relationship between high NLR and PLR levels obtained from complete blood count at diagnosis and the prognosis of the disease, risk group, presence of metastasis, and stage in pediatric solid tumors. Materials and Methods: Our study is a retrospective cohort study. The patients included in the study were newly diagnosed with solid tumors at the Pediatric Oncology Clinic of Manisa Celal Bayar University Hospital between January 2014 and November 2023. The study included 35 patients who met the inclusion criteria. The cases consisted of patients diagnosed and followed up by the Pediatric Oncology Department. The gender, age, diagnosis, and tumor stage of the cases were recorded by reviewing patient files and the hospital's HBYS system. Laboratory parameters at the time of diagnosis, including leukocyte, neutrophil, lymphocyte, and platelet levels, as well as imaging results and pathology reports, were also recorded. Patients with elevated NLR and PLR levels were categorized based on their tumor stage, the presence of metastasis, and prognosis. Results: According to demographic and clinical characteristics, there was no statistically significant difference in gender, risk group, stage, presence of metastasis at diagnosis, chemotherapy response, relapse, presence of metastasis, survival, or type of resection between patients with NLR levels below 2.5 and those above 2.5 (p>0.05). However, there was a statistically significant difference regarding diagnosis and tumor size (p<0.05). Among patients with a tumor size ≥10 cm, 62.5% (n=5) had NLR >2.5, whereas only 18.5% (n=5) of those with a tumor size <10 cm had NLR >2.5. The proportion of patients with NLR >2.5 was significantly higher in those with a tumor size ≥10 cm compared to those with a tumor size <10 cm (p=0.027). Similarly, no statistically significant difference was observed in gender, risk group, stage, presence of metastasis at diagnosis, chemotherapy response, relapse, presence of metastasis, survival, diagnosis, type of resection, or tumor size between patients with PLR levels below 92 and those above 92 (p>0.05). Conclusion: NLR and PLR are cost-effective and widely accessible biomarkers, and they can be used as prognostic factors in determining treatment strategies for childhood cancers. In our study, NLR was found to be statistically significant concerning tumor size. However, there are insufficient studies investigating the prognostic role of NLR and PLR levels in childhood cancers. Further research involving larger pediatric populations is needed. Future studies should be conducted prospectively and multicenter. Conducting studies with 'cancer type specific' analyses may yield more valuable results as prognostic factors. Keywords: Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, Solid Tumors