Proliferating cell nuclear antigen (PCNA) immunolabeling as a prognostic factor in axillary lymph node negative breast cancer.

The fraction of nuclei positive for proliferating cell nuclear antigen (PCNA) was determined in 205 axillary lymph node negative (pN-) breast carcinoma. The results were related to established prognostic factors and prognosis during the mean follow-up period of 11 years. The maximum fraction of PCNA-positive nuclei (PCNAmax), the average fraction of positive nuclei (PCNAtot) and the number of intensively stained nuclei/microscope field (PCNAcount) were significantly related to histological grade (p < 0.001), DNA Ploidy (p < 0.022), S phase fraction (p < 0.003) and mitotic index (p < 0.003). PCNAmax (p = 0.020) and PCNAcount (p < 0.003) predicted recurrence-free survival in univariate analysis whereas tumour diameter (p < 0.001) was an independent predictor in a multivariate analysis. In univariate survival analysis PCNAtot (p < 0.0178), PCNAmax (p = 0.0054) and PCNAcount (p < 0.001) predicted survival and in multivariate analysis PCNAcount (p = 0.006), patient age (p = 0.040) and tumour diameter (p = 0.042) were related independently to survival. The results indicate that PCNA immunolabeling has prognostic value in local breast cancer.