PCNA-LI, Ki-67 Immunostaining, p53 Activity and Histopathological Variables in Predicting the Clinical Outcome in Patients with Parathyroid Carcinoma

Abstract

Parathyroid carcinoma is uncommon and no reliable histological markers are available for predicting the clinical outcome of patients. The aim of this study was to assess the correlation between survival, histopatological markers, proliferating cell nuclear antigen (PCNA), Ki-67 antigen and the expression of the p53 nuclear protein in patients with confirmed parathyroid carcinoma (PC). The routine histological specimens from 15 patients (11 men, 4 women, median age 65 years) with confirmed PC who had died of the disease were reviewed. New specimens were also stained with the streptavidin-biotin-peroxidase complex standard technique. The labelling index (LI) of PCNA was quantified by counting 1000 cells from multiple areas in a random fashion, while immunostaining of both Ki-67 and p53 was evaluated as the percentage of positive cells. The PCNA-LI, Ki-67 (%) and p53 (%) values were 14.9±4.1 (median 13, range 2-70), 13.9±3.9 (median 11%, range 3-65%) and 38.5±4.6 (median 29%, range 19-65%), respectively. There was an inverse correlation between age of the patients and p53 (R=-0.73, p=0.002), but no correlation with both PCNA-LI (R=0.07, p=0.72) and Ki-67 (R=-0.07, p=0.79). A significant relationship (R=0.93, p<0.01) between PCNA-LI and Ki-67 was found, while p53 did not correlate with either PCNA-LI (R=-0.11, p=0.71) or Ki-67 (R=-0.05, p=0.86). An inverse correlation (R=-0.63, p=0.01) between survival and the presence of spindle cells and coagulation necrosis together in the standard slides was observed, but there was no correlation (p=NS) between survival and PCNA-LI (R=0.05), Ki-67 (R=0.05) or p53 (R=0.25). In conclusion, none of the tested immunohistochemical markers were useful in predicting the clinical outcome of patients with PC. However, the presence of spindle cells and coagulation necrosis together in the standard specimens should be considered as a negative prognostic factor.