Clinicopathological significance of cancer-associated fibroblasts in papillary thyroid carcinoma: a predictive marker of cervical lymph node metastasis

Purpose Most tumors have obvious biologically active fibroblasts known variously as myofibroblasts or cancer-associated fibroblasts (CAFs) in the stroma. CAFs have been known as an important factor of cancer invasion and metastasis. This study aimed to investigate the presence of CAFs in patients with papillary thyroid carcinoma (PTC) and evaluate the correlation between CAFs and cervical lymph node (LN) metastasis in PTC through immunohistochemistry. Methods The medical records of 128 patients who were diagnosed with PTC from January 1, 2010 to December 31, 2010 were reviewed, and 78 patients who underwent total thyroidectomy with or without neck dissection, were included in this study. A retrospective pathological evaluation was performed to verify the presence of CAFs. CD34 and a-smooth muscle actin (SMA) were used as markers of CAFs. Results Among 78 patients with PTC, 65 had desmoplastic stromal reaction around the PTC. Through immunohistochemical study of anti-CD34 and alpha-SMA antibodies, CAFs were found in 42 (64.6%) cases with desmoplastic stroma around the PTC. Univariate analysis showed that tumor size and CAFs were the risk factors of LN metastasis in patients with PTC, while multivariate analysis revealed that CAFs were the only independent risk factor of LN metastasis in patients with PTC. Conclusion This study revealed the presence of CAFs in PTC. Furthermore, CAFs were found to be a risk factor of LN metastasis in PTC. Therefore, CAFs may be used as a predictive marker for LN metastasis in patients with PTC.