Diagnostic performance of parafibromin immunohistochemical staining for sporadic parathyroid carcinoma: a meta-analysis

It is a challenge to distinguish parathyroid carcinoma (PTCA) from benign parathyroid lesions without recurrence or metastasis. Parafibromin immunohistochemical (IHC) staining had been described for the diagnosis of PTCA. But great variations existed in the reported sensitivity and specificity among different studies. We conducted a meta-analysis to summarize the diagnostic accuracy of parafibromin staining for PTCA. Published studies from Pubmed, Embase, and Cochrane Library were searched using the combination of terms "parafibromin," "CDC73," "HRPT2," and "parathyroid." Pooled sensitivity and specificity with 95 % confidence interval (CI) were calculated and the summary receiver operator characteristic (SROC) curves were constructed. The heterogeneity among included studies was evaluated and possible reasons were explored by meta-regression. A total of 10 studies including 202 patients with PTCA were finally enrolled in this meta-analysis. For parafibromin staining, sensitivity varied from 29 to 100 % (pooled estimate of 68 %; 95 % CI 49-82 %) and specificity ranged from 61 to 100 % (pooled estimate of 95 %; 95 % CI 85-98 %). The AUC for parafibromin staining was 0.91 (95 % CI 0.88-0.93). A significant heterogeneity was observed among included studies. According to meta-regression analysis, the scoring criteria and parafibromin antibody used in IHC were the covariates influencing the sensitivity. And the specificity decreased if atypical parathyroid adenomas were included in the control groups. The specificity of parafibromin staining was satisfactory for diagnosis of PTCA, while the sensitivity was limited. We suggested that a standardized IHC protocol and scoring system criteria should be applied in future studies to improve the diagnostic performance of parafibromin staining.