title: Comparison of the clinicopathological behavior of the follicular variant of papillary thyroid carcinoma and classical papillary thyroid carcinoma: A systematic review and meta-analysis.
abstract: The follicular variant of papillary thyroid carcinoma (FV-PTC) is the second most common type of papillary thyroid carcinoma (PTC), and it has been increasingly diagnosed in recent years. However, whether FV-PTC behaves differently from classical PTC (C-PTC) remains controversial. To address this controversy, a meta-analysis was performed to determine the potential differences between FV-PTC and C-PTC in their clinicopathological behavior. The relevant published studies between January 1, 2003 and August 31, 2014 were reviewed according to the defined selection criteria using the PubMed database. Review Manager was used to calculate the pooled odds ratio (OR) or the mean difference (MD) with a 95% confidence interval (CI), using a random- or fixed-effect model for all analyses. In total, 112 studies were identified and examined; finally, only 36 studies met the inclusion criteria. In the 36 studies, compared to the clinicopathological behavior of patients with C-PTC, patients with FV-PTC had the following parameters: Similar mean age and similar prevalence of gender, tumor size ≥10 mm, multifocality, capsular invasion, vascular invasion, lymphocytic and/or Hashimoto's thyroiditis, and clinical stage; a larger mean tumor size and higher prevalence of age ≥45 years; and lower prevalence of extrathyroidal extensions, lymph node metastases,BRAFmutation and recurrence. The meta-analysis suggested that patients with FV-PTC have a more favorable clinicopathological behavior and improved prognosis compared to patients with C-PTC. Thus, patients with FV-PTC and C-PTC may be managed differently, and the two types of PTC should be clearly distinguished in future retrospective or prospective studies.
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Shuping
authors.initials: S
authors.lastname: Yan
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Qingquan
authors.initials: Q
authors.lastname: Shi
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Jingqiang
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Rixiang
authors.initials: R
authors.lastname: Gong
keywords: classical; follicular; meta-analysis; papillary; thyroid carcinoma