Active surveillance of low-risk papillary thyroid cancer: A meta-analysis.

Background: This study evaluates the safety and efficacy of active surveillance for low-risk papillary thyroid carcinoma. Methods: MEDLINE, EMBASE, and PubMed were searched from inception for relevant studies of active surveillance for low-risk papillary thyroid carcinoma, defined as T1 a or T1 b, NO, MO disease. Main outcomes of interest were growth of primary tumor, metastatic spread, thyroid cancer-related mortality, and disease recurrence after delayed thyroid surgery. Results: Nine publications with 4,156 patients were included. Primary analysis of the 9 studies revealed pooled proportion of tumor growth during active surveillance to be 4.4% (95% confidence interval 3.2-5.8%). The pooled rate of metastatic spread to cervical nodes was 1.0% (95% confidence interval 0.7-1.4%), and pooled mortality due to thyroid cancer was 0.03% (95% confidence interval 0.0005-0.2%). Eight studies assessed incidence of delayed thyroid surgery with pooled proportion of 9.9% (95% confidence interval 6.4-14.0%). The main indication for surgery was patient preference, not disease progression, at 51.9% (95% confidence interval 44.9-58.9%). The pooled proportion of recurrence after delayed thyroid surgery was 1.1% (95% confidence interval 0.1-3.8%). Conclusion: Active surveillance appears to be a safe alternative to surgery for the management of low-risk papillary thyroid carcinoma, without increased risk of recurrence or death. This strategy allows for avoidance of exposure to surgical risk and need for subsequent thyroid replacement therapy. (C) 2019 Elsevier Inc. All rights reserved.