Correlations of PCNA expression with thyroid cancer ultrasound and histopathologic features.

Objective: To investigate the correlations of proliferating cell nuclear antigen (PCNA) gene expression with thyroid cancer (TC) ultrasound (US) features, histopathology and clinical stage.

Methods: A total of 66 TC patients admitted and treated in the Department of Oncology of our hospital from April 2014 to April 2018 were enrolled randomly. The conventional US imaging data of the patients were collected. Paired carcinoma and para-carcinoma tissues were obtained after operation to detect the expression of PCNA protein by immunohistochemistry (IHC). The correlations of PCNA expression with the patients' US manifestations and clinical stages were analyzed.

Results: The positive rate of PCNA was 72.73% (48/66) in TC tissues and 13.64% (9/66) in paired para-carcinoma tissues, displaying a statistically significant difference between the two groups (<0.05). The PCNA and US features suggested that there was no significant difference in tumor boundary between the PCNA positive group and PCNA negative group (>0.05). However, significant differences in tumor diameter, echo, calcification and blood flow were found between the two groups (<0.05). The pathologic data of preoperative US diagnosis and PCNA expression in postoperative TC specimens were analyzed, and the results indicated that PCNA expression was prominently associated with T stage and N stage in US diagnosis (<0.05). The total correct rate of US in assessing the T stage was 75.8% (50/66), and the over-staging rate and under-staging rate in evaluating the T stage were 13.6% (9/66) and 10.6% (7/66), respectively.

Conclusion: The expression of PCNA protein in TC tissues is significantly correlated with the diameter, echo, calcification and blood flow of US features as well as clinical stage detected by US. PCNA level and US examination can provide certain clinical values for TC treatment.