povidone-iodine and Thymus-Neoplasms

Hyperthermic pleural lavage with povidone-iodine (PVP-I) is utilized to control micrometastatic disease following cytoreductive surgery for thymic epithelial tumours (TETs). Our objective was to investigate whether PVP-I demonstrates direct cytotoxicity against human TET cells.. Human Met-5A (immortalized mesothelial cell), IU-TAB-1 (thymoma) and Ty-82 (thymic carcinoma) cell lines were treated with serial dilutions of PVP-I (0.01-10%) for 5, 30 and 60 min at 37°C and 42°C. MTT assays and flow cytometry were used to evaluate cell death and apoptosis. Membrane permeability was assayed by intracellular staining of cleaved poly-ADP-ribose polymerase. Cellular fixation was evaluated by membrane disruption of dead cells by dimethylsulphoxide and by comparing cleaved poly-ADP-ribose polymerase staining following PVP-I with known fixatives.. MTT assays demonstrated that PVP-I concentrations greater than 0.5% led to rapid cell death in both TET cell lines regardless of temperature. IC50 values following 5 min of exposure to PVP-I were 8.4 mM (0.3%) and 13.3 mM (0.48%) for IU-TAB-1 and Ty-82, respectively and 8.9 mM (0.32%) for MeT-5A. Flow cytometry demonstrated that 5-min exposure of either cell line to 1% PVP-I resulted in profound cell death: 74% and 58% at 5 min and 97% and 95% at 30 min, for IU-TAB-1 and Ty-82 cells, respectively. Resistance of PVP-I-treated cells to dimethylsulphoxide lysis and similar cleaved poly-ADP-ribose polymerase expression following PVP-I and known fixatives revealed cellular fixation as the mechanism of death following PVP-I exposure.. PVP-I results in rapid death of human TET cells and normal mesothelial cells through a cellular fixation mechanism and may, therefore, favourably impact the control of micrometastatic disease following resection of TETs with pleural dissemination.

Topics: Anti-Infective Agents, Local; Apoptosis; Cell Line, Tumor; Humans; Neoplasms, Glandular and Epithelial; Povidone-Iodine; Thymus Neoplasms

The optimal treatment for Masaoka stage IVA thymoma remains controversial. Whilst extrapleural pneumonectomy (EPP) has been proposed, we sought to examine the results of our institutional preference for induction chemotherapy, cytoreductive surgery and intraoperative hyperthermic pleural irrigation. We undertook a retrospective study of patients undergoing surgery for Masaoka stage IVA thymoma following induction chemotherapy over a three-year period at our institution. Between February 2007 and February 2010, 42 patients underwent surgery for thymoma. Six patients underwent surgery with intent to perform cytoreductive surgery and intraoperative hyperthermic pleural irrigation. Complete cytoreductive surgery was not feasible in one patient and thymectomy only was performed. One patient had re-operation for recurrent disease 24 months after the first operation and there were therefore seven procedures undertaken in six patients during the study period. There were no in-hospital deaths. Median follow-up was 18.8 months (range 1.5-31.9 months). One patient died 14 months postoperatively from an acute cardiovascular event. The four remaining patients are alive and well with no evidence of disease recurrence. Multimodality therapy consisting of induction chemotherapy and cytoreductive surgery is a safe, feasible treatment for stage IVA thymoma. Our experience suggest that full pleurectomy is an alternative to EPP.

Topics: Chemotherapy, Adjuvant; Female; Humans; Hyperthermia, Induced; London; Male; Middle Aged; Neoadjuvant Therapy; Neoplasm Recurrence, Local; Neoplasm Staging; Pleural Cavity; Pleural Neoplasms; Povidone-Iodine; Reoperation; Retrospective Studies; Therapeutic Irrigation; Thoracotomy; Thymectomy; Thymoma; Thymus Neoplasms; Time Factors; Treatment Outcome

Topics: Chemotherapy, Adjuvant; Humans; Hyperthermia, Induced; Neoadjuvant Therapy; Neoplasm Recurrence, Local; Neoplasm Staging; Pleural Cavity; Pleural Neoplasms; Povidone-Iodine; Reoperation; Therapeutic Irrigation; Thoracotomy; Thymectomy; Thymoma; Thymus Neoplasms; Time Factors; Treatment Outcome