The study aims to assess changes in incidence and malignancy risk over the past decade and to identify effective strategies for adapting treatment approaches.
Methods
Two consecutive samples were taken to estimate the rate of Bethesda IV reports.
1) 40696 patients submitted to FNAB of thyroid nodules during 2010-2012 in SPBU Hospital.
2) 72997 patients in 2019-2022.
To evaluate ROM, we formed two continuous samples of Bethesda IV patients operated at St. Petersburg University Hospital. 3514 patients underwent surgery in 2010-2012. 4399 patients in 2020-2021.
Results
The incidence of malignant neoplasms has risen significantly. In 2010-2012, only 15.9% of final histological diagnoses were malignant, whereas this rate increased to 29.77% in 2019-2022. This difference is statistically significant (Chi^2=33.56, p<0.0000001). In contrast, the incidence of Bethesda VI remained stable, at 3.01% in 2010-2012 and 3.07% in 2019-2022, indicating that the increase in malignancy rates is not due to changes in diagnostic criteria.
Risk of malignacy in 2010-2012 was 15,9%. In 2020-2021 was 29,77% (20,86% after ocasionaly found lesions were censored)
No significant differences in demographics were observed. The substantial rise in the number of masses necessitating surgical intervention led us to conduct ROC analysis to determine the marginal size of follicular tumors and the risk of missing aggressive thyroid cancer (AUC=0.84). For nodules with a diameter of 2 cm, sensitivity=0.84, specificity=0.60, NPV=0.9983. For nodules with a diameter of 3 cm, sensitivity=0.80, specificity=0.79, NPV=0.9984.
Conclusions
We've observed a notable increase in the need for surgical care related to follicular neoplasia. Additionally, there has been a rise in the percentage of malignant tumors identified in final histology. Genetic assessment and selective active surveillance provide a better balance between the heightened risk of surgical complications and the potential for tumor progression. For nodules smaller than 3 cm, active surveillance seems to be safe.
