Expression of PCNA in non-small cell lung cancer before and after treatment with cisplatin and vepeside.

The purpose of the study was to assess expression of the proliferating cell nuclear antigen (PCNA) in non-small cell lung cancer (NSCLC) after administration of cisplatin and vepeside in patients with clinical stage IIIA and to define a relationship between PCNA expression and tumour responsiveness to preoperative chemotherapy. An immunohistochemical study with a mouse monoclonal antibody against PCNA (Novocastra, Clone PC10, IgG2a Class) was performed on paraffin embedded specimens using the ABComplex/HRP method. Material for study was available from 35 patients and consisted of biopsy specimens obtained from neoplastic infiltrate before chemotherapy and tumour specimens obtained from the same patients during surgery 3-4 weeks after chemotherapy. PCNA immunoreactivity was observed in all the cases (100%) both before and after chemotherapy. Despite treatment with cisplatin and vepeside prior to surgery the PCNA index (IPCNA) was significantly higher (p < 0.002) irrespective of tumour responsiveness to chemotherapy. There was a positive correlation (p < 0.04) between tumour size and IPCNA after chemotherapy in a group of patients with a similar extent of neoplastic infiltrate. No correlation was seen between PCNA expression in biopsy specimens and tumour responsiveness to chemotherapy.