The Ki-67/MIB-1 index level and recurrence of papillary thyroid carcinoma

Ki67 in endocrine neoplasms: to count or not to count, this is the question! A systematic review from the English language literature

BACKGROUND

Endocrine neoplasms are generally slow-growing tumors that can show hormonal activity and give metastases. In most cases they are benign and clearly malignant forms are easy to diagnose. However, borderline forms may occur and be, for the pathologists, very difficult to classify. In these cases, there is a strong need to identify factors that may aid. Official classification systems for endocrine neoplasms are based on the evaluation of proliferation and, in most cases, they rely on mitotic count. In support, the study of Ki67 is carried out which, however, has not yet been included in any official classification system, except for neuroendocrine neoplasms of the gastro-entero-pancreatic tract.

PURPOSE

The aim of the present study was to investigate the proven or unproven role of Ki67 in endocrine neoplasms, in different districts, in order to bring to light the substantial differences, in terms of proliferation, existing between neoplasms so similar, but at the same time, so different.

METHODS

A thorough search of English language literature was performed, looking for articles concerning Ki67 in five endocrine neoplasms (pituitary adenomas, thyroid neoplasms, adrenocortical neoplasms, pheochromocytomas and paragangliomas).

RESULTS

From 2170, 236 articles were selected and it was seen that the endocrine neoplasm in which Ki67 was most studied was the pituitary, where it still shows a controversial role. In other neoplasms different roles were identified.

CONCLUSION

The pathologist should be aware of the contribution that this proliferative marker can give to the diagnosis and, sometimes, to the therapy selection, for the clinician.

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

Background

To explore Ki67 expression in papillary thyroid carcinoma (PTC) and its clinical-pathological significance.

Methods

A 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.

Results

The 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.

Conclusions

Ki67 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.

Recurrence-associated genes in papillary thyroid cancer: An analysis of data from The Cancer Genome Atlas

BACKGROUND

Recurrence of papillary thyroid cancer is not uncommon, but incorporating clinicopathologic parameters to predict recurrence is suboptimal. The aim of this study was to identify systemically recurrence-associated genes using The Cancer Genome Atlas RNA sequencing database.

METHODS

A total of 504 patients with transcriptome sequencing data of the primary neoplasm were included in this study. High and low levels of expression of each gene were defined by median splits. Differences in recurrence-free survival were compared using Kaplan-Meier curves and log-rank tests. Recurrence-associated genes were subjected to functional enrichment analyses with Kyoto Encyclopedia of Genes and Genomes annotation databases and Ingenuity Pathway Analysis.

RESULTS

We found that 1,807 genes were associated with recurrence-free survival. There were 676 genes of which high expression was associated with a greater risk of recurrence. These genes were enriched in pathways involved in cell cycle regulation and DNA repair. Among 1,131 genes of which low expression was associated with recurrence, Kyoto Encyclopedia of Genes and Genomes-annotated functions were metabolism, calcium signaling, glycan biosynthesis, and the Notch signaling pathway. Canonical pathways identified by Ingenuity Pathway Analysis included RXR function, nitric oxide signaling, interleukin-8 signaling, and nutrient sensing. In addition, low expression of the majority of thyroid differentiation genes was associated with a significantly less recurrence-free survival.

CONCLUSION

Upregulation of cell cycle-regulating and DNA repair genes appears to have a negative impact on recurrence-free survival in patients with papillary thyroid cancer. Furthermore, recurrence is associated with thyroid dedifferentiation.

Characteristics of neck level VI lymph nodes in papillary thyroid carcinoma: correlation between nodal characteristics and primary tumor

Little is known about the pathological characteristics of metastatic and nonmetastatic lymph nodes (LNs) in papillary thyroid carcinoma (PTC). The aim of this study was to elucidate the pathological characteristics of neck level VI nodes and correlations with clinicopathological parameters. We investigated the clinicopathological features of 124 classical PTCs and characteristics of 850 dissected neck level VI LNs. Immunohistochemistry for nuclear factor-κB (NF-κB) and Ki-67 was performed on primary tumors, and correlations with nodal characteristics were investigated. Nodal metastasis at neck level VI was identified in 68 of 124 PTCs (54.8 %) and was significantly correlated with tumor size, tumor multifocality, extrathyroidal extension, and tumor stage. LN metastasis was significantly correlated with larger mean LN size (P < 0.001), larger size of the largest LN (P < 0.001), and more LNs (P < 0.001). The mean size of metastatic LNs (n = 233) was significantly larger than nonmetastatic LNs (n = 617) (P < 0.001). Primary tumor diameter significantly correlated with the largest LN size (P = 0.014, R (2) = 0.049), but not mean size or number of LNs by linear regression analysis. NF-κB and Ki-67 proliferation indexes were not significantly correlated with larger nodal size. These results suggested that characteristics of nodes and primary tumor would be useful criteria for making decisions about preoperative surveillance of nodal metastasis.

Significance of IMP3, Nucleophosmin, and Ki-67 Expression in Papillary Thyroid Carcinoma

The purpose of our study was to investigate the diagnostic value of expression of IMP3, nucleophosmin, and correlation of these markers with Ki-67 proliferation index in papillary thyroid carcinoma and benign neoplasms of thyroid gland. The aim was also to investigate whether there is a difference between papillary and micropapillary carcinomas with regard to clinicopathologic parameters beside IMP3, nucleophosmin, and Ki-67 proliferation index. It was concluded that IMP3 and nucleophosmin cannot be a routine diagnostic marker for discrimination of papillary carcinomas and benign lesions. IMP3 positive staining was quite scarce in IMP3 positive papillary carcinomas although specifity of IMP3 is 100%. A statistically significant correlation was not detected between nucleophosmin, IMP-3, and Ki-67 proliferation index. A statistically significant correlation was found between tumor size, lymphovascular embolism, and Ki-67 proliferation index. There was also significant correlation between tumor size and lymphovascular embolism.

Differential expression patterns and clinical significance of estrogen receptor-α and β in papillary thyroid carcinoma

Background

The incidence of papillary thyroid cancer (PTC) is markedly higher in women than men during the reproductive years. In vitro studies have suggested that estrogen may play an important role in the development and progression of PTC through estrogen receptors (ERs). This study aimed to investigate the expression patterns of the two main ER subtypes, α and β1 (wild-type ERβ), in PTC tissue and their clinical significance.

Methods

Immunohistochemical staining of thyroid tissue sections was performed to detect ER expression in female patients with PTC (n = 89) and nodular thyroid goiter (NTG; n = 30) using the Elivision™ plus two-step system. The relationships between ER subtype expression and clinicopathological/biological factors were further analyzed.

Results

The positive percentage and expression levels of ERα were significantly higher in female PTC patients of reproductive age (18–45 years old; n = 50) than age-matched female NTG patients (n = 30), while ERβ1 exhibited the opposite pattern. There was no difference in ERα or ERβ1 expression between female PTC patients of reproductive age and those of advanced reproductive age (>45 years old; n = 39). In the female PTC patients of reproductive age, ERα expression level was positively correlated with that of Ki-67, while ERβ1 was negatively correlated with mutant P53. Furthermore, more patients with exclusively nuclear ERα expression had extrathyroidal extension (ETE) as compared with those with extranuclear ERα localization. VEGF expression was significantly decreased in female PTC patients of reproductive age with only nuclear ERβ1 expression when compared with those with extranuclear ERβ1 localization. In PTC patients of advanced reproductive age, neither ERα nor ERβ1 expression showed any correlation with that of Ki-67, mutant P53, VEGF, tumor size, TNM stage, ETE, or lymph node metastases.

Conclusions

The differential expression patterns of the two ER subtypes between PTC and NTG indicate that ERα may be a useful immunohistochemical marker for differential diagnosis of PTC. The associations of ER subtype expression with Ki-67, mutant P53, VEGF expression and ETE in female PTC patients of reproductive age suggest that estrogen-activated ERα may mediate stimulatory effects on PTC growth and progression whereas ERβ1 has some inhibitory actions.