Aims: To evaluate the prognostic value of the proliferation-associated antigen p27 in malignant mesothelioma.
Methods and results: Sections from 36 patients with malignant mesothelioma were immunohistochemically stained for the p27 antigen. The results were quantified by recording the proportion of positively stained nuclei and these data were tested for association with patient survival. p27 expression was also compared with tumour type, MIB-1 expression, apoptotic and mitotic indices. Patients with pleural malignant mesothelioma showing low p27 expression (< 53% of cells positive) survived for significantly shorter periods of time than those with high p27 expression (> or = 53% of cells positive) (P=0.04). The 50% survival time of subjects with low p27 was 4-6 months whereas for those with high p27 expression it was 10-11 months. There was no significant association between p27 expression and MIB-1, apoptotic or mitotic indices.
Conclusions: Low p27 expression in pleural malignant mesothelioma is associated with a significantly worse prognosis. p27 appears to be an independent prognostic variable which may be of value in counselling patients with malignant mesothelioma.