182 The Mesothelioma and Radical Surgery (MARS) trial update

Pulmonary metastasectomy in colorectal cancer: time for a trial

Pulmonary metastasectomy is undertaken for a range of cancers. The questions we raise here are specifically related to colorectal cancer, the commonest tumour for which pulmonary metastasectomy is undertaken. The primary objective of metastasectomy is to increase survival. There are no randomised trials in support of this practice nor are there any other forms of controlled studies. We present a critical look at the assumption of efficacy for this surgery and propose that a trial is needed and suggest a trial design.

Malignant mesothelioma: current status and perspective in Japan and the world

Malignant pleural mesothelioma (MPM) is associated with a poor prognosis; and to make things worse, its incidence is increasing throughout the world. Surgical management of MPM is comprised of two aspects: diagnosis and resection. Surgical biopsy with thoracoscopy provides a higher yield but a higher rate of tumor cell seeding than blind biopsy. In some surgical cases, extended surgical staging with mediastinoscopy, laparoscopy, and contralateral thoracoscopy is required for the preoperative evaluation for resectablity. There are two types of surgical resection for MPM. Pleurectomy/decortication (P/D) involves removal of as much of the visceral, parietal, and pericardial pleura and the tumor as possible without removing the underlying lung. Because P/D is less radical but less invasive compared to extrapleural pneumonectomy (EPP), it can be tolerated by poor-risk patients. EPP comprises en bloc resection of visceral, parietal, and pericardial pleura and adjacent components such as ipsilateral lung, pericardium, and diaphragm, without opening the pleural cavity. EPP was considered a highly dangerous procedure with a surgical mortality of more than 30% decades ago, but its current operative mortality/morbidity rates are 4%-9% and 60%, respectively. As macroscopic complete resection is the primary goal of surgery for MPM because of its diffuse intrapleural growth, surgical resection alone is associated with poor survival. In this context, combination therapy with surgery plus chemotherapy and/or radiotherapy is currently considered the standard treatment for patients with respectable MPM. A national survey of EPP was conducted recently in Japan, and a few multicenter clinical trials will start soon.

Multidisciplinary treatment of malignant pleural mesothelioma

The incidence of malignant pleural mesothelioma (MPM) is increasing worldwide, and is predicted to peak in the next 10-20 years. Difficulties in MPM diagnosis and staging, especially of early disease, have thwarted the development of a universally accepted therapeutic approach. Single modality therapies (surgery, radiotherapy, chemotherapy) have generally failed to significantly prolong patient survival. As a result, multimodality treatment regimens have been developed. Radical surgery with extrapleural pneumonectomy and adjuvant treatments has become the preferred option in early disease, but the benefits of such an aggressive approach have been questioned because of significant treatment-related morbidity and mortality. In the past few years, there have been several major advances in the management of patients with MPM, including more accurate staging and patient selection, improvements in surgical techniques and postoperative care, novel chemotherapy regimens with definite activity such as antifolate (pemetrexed or raltitrexed)-platinum combinations, and new radiotherapy techniques such as intensity-modulated radiation therapy. Induction chemotherapy followed by surgery and adjuvant radiotherapy has shown promising results. A number of molecular alterations occurring in MPM have been reported, providing broader insights into its biology and leading to the identification of new targets for therapy. However, currently available treatments still appear to have modest results. Further studies are needed to provide evidence-based recommendations for the treatment of early and advanced stages of this disease.