Vimentin and proliferating cell nuclear antigen (PCNA) expression in node-negative breast carcinomas and their correlations with pathologic variables and prognosis

Vimentin and proliferating cell nuclear antigen (PCNA) immunohistochemical staining was performed in a series of 92 node-negative breast carcinomas and expression compared with tumour size, histological grade, nuclear grade, necrosis, lymphocytic infiltrate, oestrogen and progesterone receptors, and relapse rate. Vimentin was expressed in 13% of tumours and all positive cases were invasive ductal carcinomas. A strong relationship was noted between vimentin positivity, and both histological (P = 0.01) and nuclear grade (P = 0.02). The percentage of PCNA positive cells (PCNA index) varied from 0.2 to 70% (mean 27.45, median 28). PCNA index showed a significant correlation with histological (P = 0.001) and nuclear grade (P = 0.004). Furthermore vimentin positivity was significantly associated with high PCNA index (P = 0.002). With univariate analysis vimentin positivity and high PCNA index (> 28) were both significantly correlated with shorter disease free survival (P = 0.003 and P = 0.002 respectively) (median follow-up 84 months), while no other parameter reached significance. Using multivariate analysis PCNA index was statistically related to disease-free survival (P = 0.05), whereas vimentin lost its significance. Our results suggest that PCNA may be useful in identifying node-negative breast cancer patients at risk of recurrence.