Evaluation of the significance of tumor stromal patterns and peri-tumoral inflammation in head and neck squamous cell carcinoma with special reference to the Yamamoto-Kohama classification.

Abstract

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide with 878,348 new cases. Cancer-associated fibroblasts (CAFs) are the predominant cell type in tumor stroma and are important promoters of tumor progression. The aim of the study was to evaluate the pattern of desmoplastic stromal reaction and peri-tumoral inflammatory infiltrate with the histological grade and clinical data. A total of 60 cases of HNSCC were included in the study. The hematoxylin and eosin (H and E)-stained sections from all cases were examined by two experienced pathologists for the grade, nature of stomal reaction (SR), peri-tumoral inflammatory infiltration, Yamamoto-Kohama classification grade, worst pattern of invasion (WPOI), depth of invasion (DOI), and other histopathological parameters. Correlation analysis was conducted using the Chi-square test. P-value less than 0.05 was considered statistically significant. Immature SR was not observed in any of the well-differentiated squamous cell carcinoma (SCC) cases. However, one (3.7%) case of moderately differentiated SCC and two (28.6%) cases of poorly differentiated SCC showed signs of immature SR. In the case of the higher grades of the YK classification, specifically grades 4C and 4D, a more profound depth of tumor cell invasion, equal to or exceeding 10 mm, was evident in six (66.67%) and two (28.57%) cases, respectively. Additionally, among the seven (11.7%) cases classified as poorly differentiated carcinoma, three (42.85%) displayed a WPOI score of 5. SR and the tumor invasive pattern in HNSCC are related to prognosis and may indicate tumor aggressiveness.