A study of tumour infiltrating lymphocytes and neutrophil to lymphocyte ratio in papillary carcinoma thyroid

Abstract

Background: Papillary thyroid carcinoma accounts for 70-80% of all diagnosed thyroid carcinomas. Immune response including systemic inflammation is thought to be essential for suppression of carcinogenesis. This study aims to correlate the tumour infiltrating lymphocytes (TIL) and neutrophil to lymphocyte ratio (NLR) in various demographic data and histomorphological features of papillary carcinoma thyroid. Methods: A total of 60 cases of papillary carcinoma were taken from a period between January 2018 and July 2021. TIL was analyzed as diffuse or focal at the area of highest concentration and was graded subjectively as: absent (no lymphocytes), mild (1-10%), moderate (>10-50%) and dense (>50%). NLR was calculated as the neutrophil count divided by the lymphocyte count, based on the preoperative complete blood cell counts. Results: The cases belonged to age group varying from 20 to 75 years with female preponderance (88.3%). In this study, there was significant correlation between TIL and tumour stage with a p value of 0.001. Lower the tumour stage, higher was the concentration of TIL. A cut of value of 2.17 was taken for NLR. Cases with diffuse, moderate to dense peritumoural lymphocytes had lower NLR and were statistically significant. High NLR was also seen in higher TNM stage. On the other hand, there were no association with gender, age, tumour size, histological subtype and focality with NLR. Conclusions: As an index of inflammation, tumour infiltrating lymphocytes and NLR can be considered. We found increased TIL in lower tumour stage and increased NLR values in higher tumour stages.