Purpose: In the current era of de-escalation of surgical treatment for low-risk thyroid cancer, it is important to ensure that the natural history of thyroid cancer is as benign as has been suggested previously. We therefore compared the impact of surgery refusal and surgery on disease-specific survival (DSS) in patients with local or regional, papillary thyroid cancer (PTC).
Methods: Local and regional stage PTC patients in the Surveillance, Epidemiology, and End Results Program (1988-2015) were included. Cox proportional hazard modeling and propensity score matching were conducted to evaluate DSS.
Results: There were 45,136 patients who received surgery and 146 patients who had surgery recommended but refused. Adjusted analysis showed a significantly better DSS for the surgery group compared with the refusal group (HRadj: 3.07 (95% CI: 1.54-6.11). After stratification for stage, no statistically significant difference in DSS was found (HRadj: 3.03 (0.89-10.35) when including only local stage PTC. Propensity matching showed a 10-year DSS of 94.0% (95% CI: 87.7-97.1%) and 96.4% (95% CI: 93.2-98.1%) for the refusal and surgery group (p = 0.060). Propensity matching of local stage PTC showed a 10-year DSS of 96.7% (95% CI: 89.9-98.9%) and 100%, respectively (p = 0.002).
Conclusion: Although no significant difference in survival was found between surgery and no surgery in local stage PTC, a 3.3% improvement of 10-year DSS was found in the surgery group. Overall, these results suggest that local stage PTC has a benign natural history, and that conservative management strategies such as active surveillance may be appropriate.
Keywords: Natural course; Oncological outcomes; Surgery; Thyroid cancer.