Role of matrix metalloproteinases and their inhibitors in the development of cervical metastases in papillary thyroid cancer

Objective To investigate the role of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the development of cervical metastases in papillary thyroid cancer. Our hypothesis is that level of expression of MMPs and TIMPs is associated with the development of cervical metastases and the pattern of metastatic process in papillary thyroid cancer. Design This research retrospectively investigates the expression of MMP-1, -2 and -9 as well as TIMP-1 and -2 in papillary thyroid carcinoma tissue. Tissue specimens were immunohistochemically treated with primary monoclonal antibodies against MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2. Setting Single-centre study. Participants In total, samples of 159 patients were analysed. In all patients, total thyroidectomy was performed, whereas 102 patients underwent selective neck dissection of either central (level VI) or lateral neck (level II-V). Subjects were divided into four groups. Main outcome measures Matrix metalloproteinases and TIMPs expression values were analysed in each group, and groups were compared to each other. Results Total number of patients was 159, of which 125 were women and 34 men. Comparing expression levels of MMPs and TIMPs in metastatic (study groups) and non-metastatic (control group), papillary thyroid carcinomas yielded significant differences in MMP-1 and TIMP-1 expression levels, where the highest expression values were found in the group with metastasis in lateral neck. Expression levels of MMP-2, MMP-9 and TIMP-2 did not differ statistically significant among the groups. Conclusion Elevated expression of MMP-1 and TIMP-1 in tumour tissue can be considered a predictive factor for the development of metastases.