Prognostic role of proliferating cell nuclear antigen in lung cancer: an immunohistochemical analysis.

ABSTRACT

Proliferating cell nuclear antigen (PCNA) is a 36 kDa protein acting as a subunit of DNA polymerase delta, and is therefore associated with DNA replication. Its involvement in DNA excision repair after DNA sub-lethal damage has been reported. We assessed the immunohistochemical expression of PCNA in 94 lung cancer specimens in order to evaluate its potential relationship with clinical history and the outcome of the evaluated patients. We found PCNA protein expressed in all the evaluated neoplastic specimens, but with different expression levels. In addition, our results showed a subgroup of patients (high expressors) having a statistically significant worse outcome compared to the other two groups of patients, independently of' any other clinico-pathological feature. In conclusion, our data highlight the central role of PCNA and estimation of the proliferation rate in the prediction of the prognosis of lung cancer patients.