Chromosome number correlates with survival in patients with malignant pleural mesothelioma

Modal (MO) and mean (ME) chromosome numbers determined by cytogenetic analysis were compared with survival in 34 patients with diffuse malignant pleural mesothelioma. The patients with normal chromosome number and no clonal abnormalities (MO = 46) survived longer (median survival 17 months) than patients with clonal abnormalities. MO greater than 46 correlated with shorter survival (median 12 months) (p = 0.0186). The correlation was more clear between mean chromosome number (ME) and survival: the median survival of patients with ME greater than 46 was 13 months whereas that of the patients with ME less than 46 was 26 months and ME = 46 (normal chromosome number and no clonal abnormalities) 31 months (p = 0.0007). Furthermore, there was a tendency of an association between ME = 46, ME less than 46 and epithelial subtype reported to be associated with a favorable prognosis in mesothelioma. The addition of chromosome material may present a mechanism to enhance expression of genes important in the pathogenesis of mesothelioma and lead to more aggressive behavior of the tumor.