PROGNOSTIC-SIGNIFICANCE OF KI-67 ANTIGEN AND P53 PROTEIN EXPRESSION IN PANCREATIC DUCT CARCINOMA - A STUDY OF THE MONOCLONAL-ANTIBODIES MIB-1 AND DO-7 IN FORMALIN-FIXED PARAFFIN-EMBEDDED TUMOR MATERIAL

Formalin-fixed paraffin-embedded material from 57 patients in whom cur ative resection of pancreatic carcinoma had been attempted was analyse d by an immunohistochemical procedure to estimate proliferation and p5 3 protein expression. Using the monoclonal antibody (MAb) MIB-1, which recognizes a Ki-67 epitope, the proliferating cell index (PCl, percen tage of immunoreactive tumour nuclei) and proliferating cell area (PCA , percentage of immunoreactive tumour nuclear area) were calculated us ing an interactive image analysis system and were compared with semiqu antitative scoring of stainability. MAb DO-7, which recognizes both wi ld- and mutant-type p53 protein, was used to assess p53 expression in the same material. MIB-1 stainings were of high quality in 53 tumours. The median PCI was 29.7% (range 0.5-82.1%) and the median PCA was 10. 6% (range 0.0-36.5%). There was a close correlation between PCI and PC A (P < 0.0001). PCI and PCA values were in conformity with the semiqua ntitative scoring (P < 0.0001). The p53 immunohistochemical stainings were successful in 48 tumours and the protein was expressed in 22 (46% ). High PCI values (> 45%, n = 14) correlated with shorter survival ti me (P < 0.01). PCA(P < 0.05) and the expression of p53 protein (P < 0. 001) were independent prognostic variables.