Preoperative Serum Lipids as Novel Predictors of Survival in 3575 Papillary Thyroid Cancer Patients.

Purpose: The objective of this study is to investigate the association between preoperative serum lipids levels and papillary thyroid cancer (PTC) patients' outcomes.

Methods: A retrospective cohort study including 3575 PTC patients from year 2012-2016 with follow-ups in our institute were enrolled. Preoperative serum lipids were divided into categorical variables by Receiver-operating curves. Univariable and multivariable cox regression models were developed and independent risk factors were used to construct a nomogram to predict disease-free survival (DFS) rate.

Results: Among the 3575 patients, the mean follow-up time was 56.7 months. Comparing with the patients with high level of triglycerides (TAG≥0.605 mmol/L) and high-density lipoprotein (HDL≥0.935 mmol/L), those with low level of TAG (hazard ratio [HR] 2.28 [95% CI, 1.35-3.83]) and HDL (HR 1.64, [1.02-2.62]) had a significantly higher risk of recurrence in PTCs. The 5-year DFS rate of patients with low level of TAG was 94.4%, which was much lower than that in the high level group (97.2%, P＜0.001). While TC (P = 0.13), LDL (P = 0.07) and VLDL (P = 0.15) were not statistically correlated with PTCs' recurrence. The nomogram model showed clinical predictive value with the c-index of 0.80 (95% CI 0.73-0.87) and 0.82 (95% CI 0.73-0.90) for 3- and 4-year DFS in the training cohorts.

Conclusion: In the present study, we provide initial evidence that low levels of TAG and HDL were independently associated with the recurrence of PTC, indicating that preoperative serum concentrations of lipids are helpful in predicting PTC patients' prognosis in clinical practice.