Sarcomatoid Mesothelioma Treatment

The general treatment plan for sarcomatoid mesothelioma focuses on:

Managing pleural effusions
Administering radiotherapy to intervention sites
Evaluating suitability for radical surgery
Evaluating suitability for chemotherapy and clinical trial entry

Managing pleural effusions

Initially, therapeutic thoracocentesis is used to manage malignant pleural effusions. It involves evaluating the response of dyspnea in relation to fluid removal. If thoracocentesis fails to provide relief from or alleviate symptoms, doctors need to identify other causes of dyspnea such as pulmonary thromboembolic disease, or lymphangitis carcinomatosis. Timely and effective management of pleural effusions using pleurodesis is vital for symptom palliation and for preventing a trapped lung. However, when thoracocentesis is administered repeatedly, it can cause the pleural fluid to undergo loculation. This makes it difficult to drain out the accumulated fluid and also increases the risk of pleural infection. In case of a conclusive diagnosis, chemical pleurodesis can be carried out using a small bore intercostal chest drain. The success rate of this technique is equivalent to that achieved via larger bore chest drains. Another benefit is that there is less patient discomfort. Sterile talc is the ideal sclerosing agent having a success rate of around 70-96%. However, it is necessary to ensure that talc particles have optimal calibration in order to prevent a rare, yet potential occurrence of Adult Respiratory Distress Syndrome.

In case a definitive diagnosis has not been made, and if the patient is fit enough to undergo surgery, then thoracoscopy is a useful technique for the management of potential malignant pleural effusions. This procedure allows doctors to achieve visualization of the pleural surface, carry out histological sampling for diagnosis and completely drain out accumulated pleural fluid followed by pleurodesis through talc poudrage.

In case of patients diagnosed with a trapped lung, or when pleurodesis may have failed to deliver results, a pleuro-peritoneal shunt can be used. Although symptoms are known to improve in more than 90% of patients, complications such as shunt occlusion and infection can occur in 15% of cases. As such, their use is constantly diminishing. More recently, a new system has been developed, called the ambulatory pleural drainage system (Pleurx Pleural Catheter, Denver Biomedical Inc). This new system allows patients to manage their pleural effusion at their homes through the use of vacuum bottles and a long-term drainage catheter. This is especially useful for patients diagnosed with trapped lungs since it palliates dyspnea and eliminates the need for surgical procedures.

Radiotherapy for sarcomatoid mesothelioma

Palliative radiotherapy

Radiotherapy has reported to be useful in controlling local tumor growth and in specific cases, has resulted in regression of disease. However, there is no conclusive evidence that radiotherapy alone influences survival. Radiotherapy is effective in the palliation of pain, and it has been noted that around 50% of patients who have been administered radiotherapy derive some benefit. Evidence is also available to show that short courses involving radiotherapy (for instance 20 Gy in 5 fractions) offer the same benefits as longer courses, for instance 30 Gy in 10+fractions. However, the total dose response effect may vary. Unfortunately, radiotherapy is rarely useful when it comes to palliation of dyspnea or managing mediastinal infiltration symptoms, for example, superior vena caval obstruction (SVCO). In such cases, alternative treatment methods, for example, SVC stenting should be considered.

Radical radiotherapy - when used as a single modality

Although hemithorax irradiation is known to provide symptomatic relief, none of the research studies have suggested that it improves survival. Sarcomatoid mesothelioma can spread to distant areas in the pleural cavity and administering radical radiotherapy over large areas can significantly increase risk of dose related damage to organs such as lungs, heart, spinal cord and liver. Consequently, a recent Cochrane review has not found any randomized clinical trial evidence that can show the usefulness of radical radiotherapy alone (or when combined with other types of treatment modalities) in mesothelioma cases. It has also been noted that this treatment renders a significant mortality. In one particular series, the rates were as high as 17%.

Radiotherapy - when used as part of multimodality treatment

Failure to prolong survival through single treatment modalities has resulted in a multimodality treatment approach for the treatment of sarcomatoid mesothelioma. The primary approach combines radiotherapy with debulking surgery and it can both affect the disease's natural history and reduce systemic recurrence. Since malignant mesothelioma can be large and irregular and due to its proximity to other vital organs, a more directed irradiation modality has been developed. Referred to as intensity modulated radiotherapy (IMRT), this treatment can help improve local tumor control while reducing risk of exposure to neighboring organs. However, in spite of the possibilities for better tumor control, IMRT can still increase potential risks related to fatal pulmonary toxicity in patients diagnosed with sarcomatoid mesothelioma.

Prophylactic radiotherapy

Mesothelioma might affect (seed) malignant cells in procedure scars. Although pain arising from these metastases is uncommon, they can create discomfort, and there is evidence that administering radiotherapy to intervention sites can help prevent this complication. While this procedure is recommended in existing guidelines, new evidence suggests that it should be administered only to those patients who show symptoms of these subcutaneous tumors since the radiotherapy itself can lead to side-effects.

Surgery for sarcomatoid mesothelioma

The role of surgery is still uncertain in the treatment of patients diagnosed with sarcomatoid mesothelioma. Three most commonly used surgical procedures are debulking surgery (also called cytoreductive surgery or pleurectomy/decortication (P/D)), surgical pleurodesis using video assisted thoracoscopic surgery (VATS) and extra pleural pneumonectomy (EPP). It involves en-bloc resection of the lung, parietal pleura, pericardium and diaphragm and mediastinal nodes. P/D allows surgeons to remove the visceral, parietal and pericardial pleura and also debulking the tumor. It is hence less demanding and mortality rates are less than 5%. However, P/D has limitations since it does not allow complete removal of the tumor, and preserving the ipsilateral lung renders postoperative radiotherapy difficult because of the potential risk of pulmonary side effects. However, the effectiveness of P/D in improving survival is debatable. While some evidence shows that P/D surgery through the VATS approach may improve survival in patients (those with advanced stages of the disease and not suitable for EPP), other research studies have not shown any significant advantage of P/D over EPP.

With high morbidity rates of around 60% and mortality rates ranging between 4-9%, EPP is a relatively more demanding procedure. However, high dose hemithoracic radiotherapy can be administered using the pneumonectomy in EPP. This combined treatment is known to reduce local recurrence and improve survival in early stages of the disease. Consequently, as a vital component of the trimodality treatment approach involving surgery, chemotherapy and radiotherapy, EPP has become the preferred treatment option, although no clear randomized controlled trial evidence is available. With a view to study this issue in more detail, a large randomized trial is currently underway, referred to as Mesothelioma and Radical Surgery (MARS). EPP, in this particular trial, comes in between the induction chemotherapy and radical chemotherapy. While the control arm facilitates full active tri-modality therapy, the surgery itself involves only debulking surgery. Moreover, the same induction chemotherapy is administered to patients and also radiotherapy to any of the drain or port sites.

To receive a FREE Mesothelioma Web information packet** or to make a request, please fill out the following form :

**For a FREE information packet including treatments, clinical trials, and specialists, please complete the form above or call a Mesothelioma Web coordinator at 1-877-367-6376.

News

Resources

This site complies with the HONcode standard for trustworthy health information: verify here

If you would like to receive a FREE information packet or have questions about mesothelioma, call us at:

Toll-Free 1-877-367-6376