Abstract

Tumor-Stroma Ratio (TSR) is a histopathological parameter reflecting the proportion between tumor cells and stromal components within the tumor microenvironment. In recent years, TSR has gained increasing attention as a novel prognostic factor in various malignancies. This review aims to summarize current evidence regarding the definition, biological basis, clinical significance, and assessment methods of TSR in pathology practice. Relevant literature was searched in PubMed, Scopus, and Google Scholar using keywords related to TSR and cancer, with priority given to cohort studies, review articles, and meta-analyses published up to March 2026. The findings indicate that a high TSR (stroma-rich tumors) is closely associated with poor prognosis, including increased risks of metastasis, vascular invasion, perineural invasion, and reduced overall survival. TSR can be evaluated on routine Hematoxylin-Eosin stained slides without requiring additional techniques, making it highly applicable in routine pathology practice. Emerging digital pathology and artificial intelligence-based approaches may further improve the accuracy and reproducibility of TSR assessment. TSR has the potential to become an important parameter for risk stratification and personalized treatment decision-making in the future.