Clinical prognostic risk assessment of different pathological subtypes of papillary thyroid cancer: a systematic review and network meta-analysis

There are multiple pathologic subtypes of papillary thyroid carcinoma (PTC), each with distinct clinical prognoses. However, the available data on the clinicopathologic risks associated with several common PTC subtypes are controversial and require more comprehensive evaluation. To address this, we conducted a systematic search of English-language databases, including PubMed, EMbase, Cochrane Library, and Web of Science, for studies on six PTC subtypes, including classic papillary thyroid carcinoma (CPTC), papillary thyroid microcarcinoma (PTMC), follicular variant of papillary thyroid carcinoma (FVPTC), tall cell variant of papillary thyroid carcinoma (TCVPTC), diffuse sclerosing variant of papillary thyroid carcinoma (DSVPTC), and columnar cell papillary thyroid carcinoma (CCVPTC). Our case-control study of clinicopathological prognostic analyses of six subtypes, with a search date of January 2000 to May 2024. Two researchers independently screened the literature, extracted data, and assessed quality and risk of bias according to set criteria. R software gemtc package, Stata 15.1 software were applied to perform reticulated Meta-analysis methods were applied to compare the clinicopathological features and prognostic assessment of classic papillary thyroid carcinoma and the other five subtypes in all the studies.The risk of distant metastasis was higher in patients with CCVPTC, TCVPTC, and DSVPTC than in CPTC.FVPTC and PTMC exhibit a lower risk of in situ tumor relapse compared to CPTC. The tumour size of TCVPTC was significantly larger than that of CPTC, while there was no significant difference in the tumour size of CCV, DSV, FVPTC, CPTC and PTMC. DSVPTC was significantly more multifocal than the other subtypes. This network meta-analysis confirms the aggressive biological behavior and poor prognosis associated with TCVPTC, DSVPTC, and CCVPTC. Therefore, these subtypes should be managed aggressively with total thyroidectomy and lymph node dissection if diagnosed preoperatively. In contrast, FVPTC and PTMC are less aggressive and have a better prognosis, suggesting that treatment and follow-up strategies for PTC should be tailored according to the histopathological subtype.