Immunohistochemical analysis of proliferating cell nuclear antigen expression in human neuroblastoma

Proliferative cell nuclear antigen (PCNA) is a cell-cycle-related nuclear protein that is maximally elevated in late G1 and S phase of proliferating cells. In this study, PCNA was identified immunohistochemically using paraffin section in 67 human neuroblastomas. Percentage of the PCNA-positive nuclei (PCNA index: PCI) ranged from 0% to 75%. There were significant relations between the PCNA expression and mitotic karyorrhexis index (MKI), histological classification, cell concentration, tumor weight, clinical stage, local invasion, lymph node metastasis, liver metastasis, or DNA ploidy. PCI was significantly low in patients who received aggressive chemotherapy before surgery. Patients with PCI higher than 30% showed a worse survival rate compared with those with PCI lower than 10% (P < .01). High PCI significantly related with poor survival, so that PCI may be an independent prognostic factor in neuroblastoma. Although further studies are required, PCNA immunostaining may be useful for assessing proliferating activity and for providing prognostic information in human neuroblastoma.