The Relationship of Fibroblast Activation Protein (FAP) Expression to Clinicopathologic Factors of Papillary Thyroid Carcinoma

Abstract

Background
Papillary thyroid carcinoma is the most common subtype among thyroid cancers. The interaction between cancer cells and tumor
microenvironment plays roles in cancer proliferation and invasiveness. One of important components of tumor microenvironment
that could stimulate tumor proliferation and invasiveness is activated fibroblast, known as carcinoma associated fibroblasts (CAFs).
The aim of this research is to analysed FAP expression is associated with clinicopathologic characteristics.
Methods
This retrospective descriptive observational study with serial cases design was conducted in 40 samples of the paraffin blocks of
tissues registered in Department of Anantomical Pathology Faculty of Medicine University of Sriwijaya/Dr. Moh. Hoesin Palembang
Hospital from January 1st, 2017 to October 31st, 2019. All samples were immunostained with FAP antibody. The expressions of FAP
were evaluated in accordance with the results of the previous study. Statistical test was performed by using Chi-square and
Spearman-rho statistical test. Statistical analysis was performed by using SPSS version 23.0.
Results
Our data indicated that patients who were ≥45 years old (21 cases; 52.5%), women (31 cases; 77.5%) suffered from this cancer the
most. The stromal type found in ten classic, follicular, solid and columnar variance were pauci (25 cases; 62.6%), desmoplastic (8
cases;20%), sclerosis (5 cases; 12.5%) and inflammatory (2 cases; 5%). The expression of FAP in tumor stroma has a significant
correlation with histopathology subtypes (p=0.028) and stromal type (p=0.000).
Conclusion
FAP was expressed in tumor epithelial cells and fibroblast stromal tumour of papillary thyroid carcinoma. FAP expression in stromal
tumor between histopathologic subtype and stromal type showed significant correlation