The 9th meeting of the International Mesothelioma Interest Group (IMIG) was held in Amsterdam from September 25-27, 2008, with Paul Baas, a medical oncologist at the Netherlands Cancer Institute (NKI) as convenor. The meeting featured sessions on all the current areas in mesothelioma research, including epidemiology, early diagnosis, imaging modalities, pathology, molecular genetics, and multimodality treatments with surgery, chemotherapy and radiotherapy.
As commonly happens, many sessions were held concurrently, and it was difficult to obtain an overview of all the most significant developments since the Chicago conference of 2006. Of the 230 presentations, one in seven had no accompanying abstract in the program book and discussion time was limited by the volume of material accepted.
There were few noteworthy additions to the current paucity of effective therapies available for treating patients with mesothelioma . Julian Peto updated the epidemiology data for those few countries that have reliable statistics, and problems in developing countries with minimal regulation of asbestos usage such as India were highlighted.
There were no significant clinical developments in chemotherapy or novel targeted agents, with cisplatin, gemcitabine and pemetrexed still the most active agents. The combination of cisplatin and pemetrexed results in stable disease in 50%, and partial response or progressive disease in 25% respectively. No major cancer centre continues to use intraoperative chemotherapy, concurrent chemoradiotherapy or photodynamic therapy, but most have adopted multimodality programs with neoadjuvant chemotherapy, radical surgery and postoperative high dose radiotherapy in operable patients.
Results of the EORTC 08031 and the MARS Trial were unavailable, and recent trimodality series which included post-pneumonectomy hemithoracic radiotherapy delivered by intensity-modulated radiotherapy (IMRT) were presented from major centres in North America (Houston, Boston, New York, Duke, Philadelphia, Tampa, Toronto and US Multicenter trial) and Europe (Zurich, Milan, Copenhagen and Heidelberg).
This approach is now (delete the accepted as) their standard therapy for early stage mesothelioma patients after PET/CT staging, and technological advances in radiotherapy planning and delivery have minimised acute and late radiation toxicities. Revised normal tissue tolerances have now been adopted, with acceptable rates of radiation pneumonitis in all the latest series.
On the second day the agenda featured a joint meeting with the European Association for Cardiothoracic Surgery, with contributions from Tom Treasure, David Waller, Eric Butchart, David Sugarbaker, Craig Stevens, Ken Rosenzweig and others. Most surgeons are now recommending radical pleurectomy over extrapleural pneumonectomy, based on large series reporting that the type of operation is not a significant prognostic factor for overall survival, and future trials will need to address this change. Randomised trials of port site radiotherapy have been inconclusive and the role of wide field radiotherapy is undergoing active re-evaluation to optimise locoregional control following pleurectomy as well as after pneumonectomy.
Other presentations of interest to thoracic surgeons and other clinicians managing patients on trials are noted. The IASLC has a new committee formed to collate staging information from surgical and non-surgical databases between 2009 to 2014, and to review the current inadequate mesothelioma staging classification, a similar process to that used for the new AJCC TNM classification of non small cell lung cancer.
Contributions from Australian centres will be welcomed. Sugarbaker presented an analysis from his Harvard database of 473 patients with epithelioid mesothelioma who underwent extrapleural pneumonectomies, to produce non-overlapping survival curves based on modifying T and N staging definitions for stage regrouping.
PET/CT scanning has become the standard imaging modality for patients on trials, and a new software program developed in Perth which objectively measures the total glycolytic volumes on sequential PET scans may improve response assessments.
The next IMIG meeting, scheduled for 2010 may be held in Sydney, with Nick Pavlakis as the nominal convenor.
