Factors influencing malignant evolution and long-term survival in solitary fibrous tumours of the pleura.

Solitary pleuro-pulmonary fibrous tumours are relatively uncommon neoplasms that are difficult to manage therapeutically and which, cytogenetically, have been poorly studied. The aim of the present work was to analyse the characteristics of a series of consecutive operated solitary pleural fibrous tumours in an attempt to discover a malignant pattern of evolution. This was a retrospective observational study of 19 cases. Samples were studied for clinical, histological, immunohistochemical and cytogenetic characteristics (aCGH, FISH). Descriptive statistics were used: the Kapplan-Meyer log-rank test and the Cox-regression model for survival analysis. Analysis of malignant evolution was achieved using 2x2 tables; significant factors were included in a binary logistic regression model. Parietal pleural implantation of the primary tumour, high mib1 expression, and low p53 expression were seen to be statistically significant factors for survival. We recommend a close follow-up for patients with a malignant primary tumour and low p53 expression and a regular long-term follow-up for benign primary tumours with a high mib1 index, high positive p53, and deletions. These findings need confirmation in more extensive series.