The clinicopathological significance of Ki67 in papillary thyroid carcinoma: a suitable indicator?

Abstract

BackgroundTo explore Ki67 expression in papillary thyroid carcinoma (PTC) and its clinical-pathological significance.MethodsA total of 776 consecutive PTC and benign thyroid disease patients underwent thyroidectomy at Shanghai General Hospital from January 2013 to December 2015 and were retrospectively analysed. Ki67 expression was determined in the PTC and benign thyroid disease tissues, and other clinicopathological factors were identified via statistical analyses.ResultsThe Ki67 expression intensity in the PTC group was significantly higher than that in the benign thyroid disease group. In the PTC group, a tumour size ≥ 1 cm and coexistence with thyroiditis were significantly associated with the Ki67 expression intensity. The TGAb and TPOAb plasma levels were linearly correlated with the Ki67 expression intensity. Moreover, the tumour size and Ki67 expression intensity also showed a linear correlation. Receiver operating characteristic (ROC) curve analysis suggested that the optimal cut-off value of Ki67 was 2.50%. Two groups divided by Ki67 cut-off values showed significant differences in the recurrence survival rate.ConclusionsKi67 is a suitable biomarker for distinguishing PTC from benign thyroid disease. Ki67 expression was related to the tumour size, thyroiditis and plasma levels of TGAb and TPOAb in PTC. Ki67 could be used as a prognostic indicator in PTC. Patients with high Ki67 expression are more likely to experience disease recurrence.

<p>JAZF1 Suppresses Papillary Thyroid Carcinoma Cell Proliferation and Facilitates Apoptosis via Regulating TAK1/NF-κB Pathways</p>

“…Ki67 is a common proliferation marker 37,38. Tang et al have demonstrated that Ki67 may be an important indicator to determine tumour aggressiveness in PTC 39. Our study verified the negative correlation between JAZF1 and Ki67, suggesting the potential role of JAZF1 as a proliferation-related protein in PTC.…”

Current and future markers for the diagnosis of thyroid cancer

“…Among recent evaluations of new IHC markers, galectin-1 was reported to display a higher specificity (97%) than galectin-3 and CK19 which showed higher sensitivity (97% and 98%, respectively), showing complementary diagnosis values [13]. In addition, Ki67 was also found as a suitable single marker for distinguishing carcinomas from benign thyroid diseases [14]. Combinations of markers were evaluated to improve differential diagnosis, especially regarding the classification of thyroid follicular lesions [15][16][17].…”

Where to “cut‐off”?

“…For example, in basal cell carcinoma, a significant correlation was observed between the Ki‐67 proliferative index and the presence of ulceration . In papillary thyroid carcinoma Ki‐67 expression was significantly higher than that in the benign thyroid disease group . In the study performed on sections of gastric and colorectal cancers where tumor labeling Ki‐67 index ranged from 10 to 85%, the high Ki‐67 expression was correlated with poor survival in colorectal cancer .…”

“…Specifically, evaluations are based on comparison and statistical analysis of groups of patients where the cut‐off of Ki‐67 antigen is separating its level of expression (proliferation index) in relation to tumor prognosis. In papillary thyroid carcinoma, the optimal cut‐off of Ki‐67 expression was 2.5% and the difference in the survival rate between two groups divided by cut‐off was of statistical significance. In the case of oral mucosa melanoma (OMM) in patients without distant metastases, the cut‐off point was 20%.…”