Fasting serum glucose and lymph node metastasis in non-diabetic PTC patients: a 10-Year multicenter retrospective study

Background: Mostly current studies are limited to the impact of lymph node metastasis(LNM) on the prognosis of papillary thyroid cancer(PTC) or the impact of glucose metabolism on the occurrence of PTC, but no one has paid attention to the connection between fasting serum glucose(FSG) and LNM. The purpose of our study was to explore the relationship between FSG and LNM in non-diabetic PTC patients. Methods: In this study, we performed a multicenter, retrospective study on 6034 non-diabetic patients with PTC. The associations of FSG with three types of LNM including central lymph node metastasis (CLNM), lateral cervical lymph node metastasis (LLNM) and both were estimated. Results: Compared with PTC patients without LNM, those with LNM had higher FSG. We also found that FSG was associated with tumor extension, maximum tumor diameter and TSH. In order to further explore the association between FSG and different types of LNM, we analyzed three groups of data separately. Our study reveals that by comparing FSG between patients without LNM and patients with three LNM types, it was statistically different in the PTC patients with CLNM and the PTC patients with CLNM combined with LLNM. Conclusion: Our study provides evidence for the association of FSG and LNM in non-diabetic PTC patients, with a gradual increase in FSG over the course of the PTC from no lymph node metastasis to CLNM combined with LLNM. Meanwhile, higher FSG is a risk factor for CLNM and CLNM combined with LLNM. In the future, FSG might be used as an indicator for lymph node dissection in PTC patients. However, larger relative studies are needed.