Thyroid. 2021 Jun 1. doi: 10.1089/thy.2021.0158. Online ahead of print.
ABSTRACT
BACKGROUND Noninvasive follicular neoplasm with papillary like nuclear features (NIFTP) reclassification has significantly influenced the field of thyroidology. However, the extent of this impact depends upon the incidence of NIFTP in a given population. In this meta-analysis, we aimed to obtain robust information about the actual incidence of NIFTP worldwide by reviewing the published data. METHODS Comprehensive literature search was performed using electronic databases of PubMed and Web of Science over a 5-year period (01.01.2016-30.01.2021). The incidence of NIFTP was calculated by dividing the number of NIFTP by the number of papillary thyroid carcinoma (PTC). Meta-analysis of proportion and their 95% confidence interval (CI) were pooled using the random-effect model. Heterogeneity across the included studies was assessed using I2 statistics. Egger’s regression test and funnel plot of estimates were used to evaluate the publication bias. P-value < 0.05 was considered significant. RESULTS From 505 publications, we finally included 50 studies, all retrospective, with 100,780 PTC and 3,990 NIFTP from 92 institutions worldwide. Our results demonstrated that the overall incidence of NIFTP was 6.0% (95% confidence interval [CI] = 4.4-8.2) among PTCs or thyroid malignancies with a high level of heterogeneity among the included studies (I2 = 98.6%). NIFTP incidence was largely similar in North America and Europe (9.3% vs. 9.6%) with a significantly lower overall rate from Asia (2.1%). There was a significant decline in the reported incidence of NIFTP in non-Asian studies published after 2017 (p = 0.002). On applying our data on global thyroid cancer statistics, this reclassification would affect ~30,881 patients annually with lower impact in Asia compared to North America and Europe. CONCLUSION This comprehensive meta-analysis confirms that the worldwide NIFTP incidence is much lower than estimated initially. The NIFTP rates are significantly lower in Asian continent as compared to North American and European countries. Apart from geography, NIFTP rates are significantly influenced by the nature of study, type of database used for sample collection and the diagnostic criteria used. Introduction of NIFTP may potentially spare over 30 thousand patients worldwide annually from clinical and psychological consequences of cancer diagnosis.
PMID:34060946 | DOI:10.1089/thy.2021.0158
