Surgery can have an important role within the treatment of malignant mesothelioma in confirming the diagnosis, assessing the spread of the tumour (stage), removing and reducing the bulk of disease and in the control of symptoms.
The diagnosis of malignant pleural mesothelioma is made most firmly by the inspection of a biopsy of the pleura under the microscope. A diagnosis confirmed by biopsy helps when planning further treatment, for some treatments it is essential and it also verifies claims for compensation.
It may be possible to obtain a reliable biopsy either by the removal of fluid from the chest (pleural fluid cytology) or a needle biopsy whereby a biopsy is obtained under local anaesthetic sometimes guided by a CT or ultra sound scanner. However, particularly in the early stages, negative results by these tests do not rule out the possibility of mesothelioma. It may be felt that a surgical biopsy is warranted.
Surgery and Diagnosis - Medical Thoracoscopy and Video Assisted Thoracoscopy
Picture Source - www.mayoclinic.org
There are two “keyhole” procedures that can be used. Under a local anaesthetic it is possible to have a medical thoracoscopy. This involves a small camera telescope being introduced through a single 1-2 cm cut from which a biopsy can be taken. If a general anaesthetic is performed, a thoracic surgeon may perform Video Assisted Thoracoscopic Surgery (VATS), through between 1 and 3 such cuts. This allows a larger biopsy to be performed and a full assessment of the pleura to be made.
Video Assisted Thoracoscopic Surgery (VATS) - Picture Source - www.thoracicgroup.com
Lung Diagram Picture Source - www.usctransplant.org
There are two approaches to surgical resection of malignant pleural mesothelioma; radical and palliative.
The intention of radical surgery is to remove all the visible tumour. With any cancer type radical surgery is performed with the aim of gaining local control in the area of the tumour, in patients in whom tests have not been able to demonstrate the spread of cancer cells elsewhere in the body. This, of course, cannot be guaranteed, as small deposits of cancer cells may be undetectable. Radical surgery is appropriate for only a small number of patients since the majority have disease that has already progressed beyond being able to be completely removed, or are not fit enough for surgery. With mesothelioma, although wide margins of normal tissue around the removed cancer are difficult to achieve, the goal of local control can be achieved in some patients. It is important to remember that, unlike radical surgery in breast, bowel and lung cancers, where it is possible to offer the chance of a cure, this is not the case in mesothelioma. It is very uncommon for patients having radical surgery to gain a cure, in other words never having further problems with mesothelioma. However, palliative surgery may have an important role in improving and controlling symptoms and maintaining the quality of life.
Radical Surgical Options
Extrapleural Pneumonectomy (EPP)
EPP was a procedure which gained initial favour amongst some surgeons in the UK and overseas, but it is now less commonly performed. It is the most aggressive surgical option but it is only appropriate for a very small number of patients. Pre-operative tests must demonstrate that patients have good, adequate lung and heart function before acceptance for surgery. EPP involves removing the entire lung and pleura together with the diaphragm and the side of the pericardium (the sac around the heart) in one piece. After removal of the tumour, the diaphragm and pericardium are reconstructed with artificial patches.
Extended Pleurectomy/Decortication (eP/D)
This procedure is also known as Radical Pleurectomy and Decortication (P/D). With eP/D, the pleura is stripped off the chest wall, but the thickened pleural membrane is peeled off the lung leaving the lung in place. The pericardium and diaphragm are often removed, depending on the extent of the tumour. eP/D is still, however, a very big operation that is only suitable for patients with sufficient reserves. As the lung remains in place, and it may function better after surgery as it can often now expand more easily, recovery from surgery may be quicker and in the longer term quality of life may be preserved or even improved. However, compared to EPP, it slightly less likely to remove all the tissue that may contain tumour cells and therefore there is a greater chance of recurrence around the operated lung. In addition, it may not be possible to administer as high a dose of radiotherapy to the chest after the operation, as it may damage the underlying lung. eP/D may still be useful for patients in whom there is possible spread of the mesothelioma to the lymph glands in the centre of the chest (mediastinum). Not all thoracic surgeons in the UK have experience of this technique and most will usually prefer to operate after a few cycles of chemotherapy have been given.
The Mesothelioma and Radical Surgery Trial (MARS)
Radical surgery will not result in a cure and it will reduce the immediate quality of life. One theory is that, following radical surgery, the progression of the disease would be slower, meaning patients would be better off in the medium and long term. By investigating in clinical trials the effects on the quality and length of life after radical surgery, compared to non-surgical treatment, it is hoped that evidence can be gathered to determine the value of surgery. The MARS trial was a study designed to examine the role of EPP in mesothelioma. The results of the MARS trial were published in July 2011. They showed that it was difficult to give the proposed combination of chemotherapy, surgery and radiotherapy. Although the study was not large enough to provide solid proof of differences in survival and quality of life, quality of life was possibly worse after EPP than the no surgery group and survival was possibly worse also. It was felt that the much larger trial of EPP was needed to be sure about any of these differences.
A trial of eP/D, in comparison, with no surgery, has recently gained funding. It is hoped that this trial will open in a number of thoracic surgery centres in the UK in 2013/2014.
The type of operation depends on whether the lung on the affected side will expand or not. If after drainage of the fluid around the lung (pleural effusion) the lung will expand, then the options are either the insertion of sterile talc around the lung to seal the space between the pleural linings (pleurodesis) or the removal of the bulk of the tumour (pleurectomy). Both these procedures can be performed reliably by keyhole surgery Video Assisted Thoracoscopic Surgery (VATS).
If, however, the lung is encased by tumour and cannot expand after fluid has been drained, then skimming the surface of the lung (decortication) will be required to make it possible for the lung to expand and thereby improve the function of the lung and improve shortness of breath. It is sometimes possible to decorticate the lung by VATS, but the majority of surgeons would perform decortication by opening the chest with a large cut made around the back below the shoulder blades, between the ribs this is called a thoracotomy. Thoracotomy and decortication is a larger procedure reserved for the younger, fitter patients. In the elderly, more infirm patient, a tunnelled indwelling pleural catheter (TIPC) can be inserted. This is a permanent drain with a valve which empties the pleural fluid into a vacuum bottle, every few days as required.
Referral for Surgery
Patients can discuss the appropriateness of surgical treatment with the doctor who is currently caring for them. Not all hospitals are able to offer surgical treatment for mesothelioma. Referral to other hospitals for treatment can be done by the hospital team currently caring for the patient or the GP where this is not feasible. Mesothelioma UK can help to identify the nearest surgical unit, where this is requested.
Surgery is frequently used across the UK to gain a diagnosis and treat pleural effusion. The provision of radical and palliative surgery may vary between parts of the UK and different hospitals. However, not all thoracic surgeons in the UK have experience of radical surgery for malignant pleural Mesothelioma and opinions can differ as to the benefits. It may be necessary for patients to be referred to a specialist centre.
© Mesothelioma UK 2013