Cancer-associated fibroblasts in thyroid cancer stroma correlate with tumour progression and desmoplasia: a histopathological study

AIM AND OBJECTIVES: Tumour stroma is acknowledged as a fundamental constituent of the tumour microenvironment, which drives cancer progression. Cancer-associated fibroblasts are an integral part of the cancer stroma. However, their role in thyroid cancer is not fully elucidated. The aim of this study is to determine the relationship between the expression of stromal cancer-associated fibroblasts' immunohistochemical biomarkers in thyroid cancer and clinicopathological features of the disease. METHODS: Eighty-five formalin-fixed paraffin-embedded tissue sections of different thyroid cancer cases were stained with Masson's trichrome, α-smooth muscle actin (α-SMA) and fibroblast activation protein (FAP) and scored based on the extent of the stained area and staining intensity. Statistical analysis was performed to assess any correlation with clinicopathological features. RESULTS: α-SMA showed a positive correlation with male gender (p = 0.02), tumour size greater than 1 cm (p = 0.0014) and histopathologic features of aggressiveness (p = 0.023). FAP was positively correlated with extent of desmoplasia (p = 0.024). Additionally, stromal desmoplasia was negatively correlated with tumour size greater than 1 cm (p = 0.0082). CONCLUSION: Cancer-associated fibroblasts are associated with increased tumour progression and desmoplasia in thyroid cancer.