p53, p21 and metallothionein immunoreactivities in patients with malignantpleural mesothelioma: correlations with the epidemiological features and prognosis of mesotheliomas with environmental asbestos exposure

The aim of this study is to investigate immunoreactivity for p53, p21 and m etallothionein in diffuse malignant pleural mesothelioma (DMPM) and to dete rmine the relationships between the age, sex, asbestos exposure time, survi val of DMPM patients with environmental asbestos exposure and immunoreactiv ity to p53, p21 and metallothionein. Sixty-seven histopathologically-confirmed DMPMs, 38 of whom had environment al and 29 had occupational asbestos exposure, were included. The tumour tis sue samples were immunostained with antibodies against p53, p21 and metallo thionein. Epidemiological data and the survival times for the DMPM patients with environmental asbestos exposures were obtained from hospital records. Thirty-three per cent of the DMPMs were positive for p53, 35% for p21 and 52% for metallothionein. There was no statistical difference between the hi stological subtypes of DMPM in terms of immunoreactivity for p53, p21 and m etallothionein. For p21 and metallothionein there was a statistically signi ficant difference between the exposure characteristics: patients with envir onmental asbestos exposure had shown more immunopositivity. There were stat istically significant differences between age groups and between asbestos e xposure times for metallothionein, and between asbestos exposure times and p21. The patients with positive immunostaining had longer exposure times an d were older than those having negative immunostaining. The differences bet ween survival of the patients were not statistically significant in terms o f the immunohistochemical results for p53, p21 and meallothionein.