Prognosis in malignant mesothelioma related to MIB 1 proliferation index and histological subtype

The aims of this study were to evaluate the use of the proliferation marker MIB 1 and histological subtype as indicators of prognosis in malignant mesothelioma. Sections from 41 cases of malignant mesothelioma were histologically subtyped on hematoxylin and eosin sections and stained immunohistochemically for the proliferation marker MIB 1. A proliferation index was derived and the results compared with patient survival data. A statistically significant difference was found between the survival of patients having a low and high MIB 1 index (P < .001). Patients with tumors having a low MIB 1 index lived significantly longer than those with a high MIB 1 index. Patients with the spindle cell histological subtype of malignant mesothelioma had significantly shorter survival times than those with the epithelioid or mixed tumors (P < .01). The MIB 1 proliferation index and histological tumor subtype are useful markers of prognosis in malignant mesothelioma.