The treatment for MPM may require surgery, chemotherapy and radiation. Depending on your stage of disease and where the cancer is located, you may receive one or more of these treatment modalities. Previously, many doctors and specialists were hesitant to recommend aggressive treatment because MPM was very resistant. However, there have been several advancements in mesothelioma therapy that have improved survival outcomes in the last few years. In some patients, aggressive therapy including surgery, radiation therapy and/or chemotherapy may result in long-term survival and perhaps cure.
The choice of treatment depends on many factors, including the location and stage of the cancer as well as the age and general health of the patient. The majority of mesothelioma patients who have been cancer-free for a long time have had surgery as part of their treatment. In patients where surgery is not an option, recent developments in new agents that target crucial pathways that regulate MPM cells have offered new hope for improving outcomes.
Surgery
The two main goals of MPM surgery are to:
- Reduce the overall volume of disease to increase the likelihood of cure with additional therapy such as radiation and chemotherapy or targeted/biologic agents.
- Relieve symptoms of pain and shortness of breath.
Two main forms of surgery are available:
Pleurectomy or Pleurectomy/Decortication (P/D) involves peeling the tumor away from the lung, diaphragm and chest wall but leaving these structures intact. In most instances, the tumor cannot be entirely removed. In these cases, it is not possible to give high doses of radiation to the chest because the lung and diaphragm remain intact. Leaving in the structures limits the total dose of radiation that can be delivered after surgery. Local recurrences are significantly higher than with extrapleural pneumonectomy, however, because the lung tissue is preserved and the patient’s lung function is usually well-maintained. MD Anderson may perform a pleurectomy or pleurectomy/decortication on patients who cannot tolerate extrapleural pneumonectomy because of poor lung or heart function.
Extrapleural pneumonectomy (EPP) is considered at MD Anderson to provide the best chance of complete tumor removal and allows for other therapies to be given with less risk to the remaining vital organs. EPP is an extensive surgical procedure that involves removal of all organs involved, including the lung, lymph glands and portions of the diaphragm and the pericardium (sac that surrounds the heart). The diaphragm and pericardium are reconstructed with a sheet of artificial material. Patients must be in good physical shape to tolerate the procedure.
Radiation Therapy
Radiation therapy alone is not a successful curative treatment for mesothelioma. However, when administered after surgery, it can reduce the chances of tumor coming back. Also, in some cases, radiation may be administered as prophylaxis to an incision site to prevent tumor recurrence or to a specific site to palliate painor symptoms of discomfort. The most common use of radiotherapy though, is after surgery to prevent disease recurrence.
There are several ways of delivering radiotherapy. MD Anderson pioneered the use of intensity-modulated radiation therapy (IMRT) after extrapleural pneumonectomy. IMRT is an advance in radiotherapy that involves giving highly accurate three-dimensional radiation after the lung and pleura have been removed. This technology may lead to improved outcomes and less toxicity to the patients over hemi-thoracic external beam radiotherapy.
IMRT for mesothelioma was developed at MD Anderson, and currently very few institutions offer it. It requires careful planning of the radiation treatment area and close collaboration between the surgeon and radiation oncologist. Areas thought to be at high risk for tumor recurrence are carefully mapped out on CT scans and analyzed by a computer, which performs three-dimensional dosage calculations. Using this technique, high doses of radiation can be very accurately administered to the entire chest cavity.
Chemotherapy
In MPM patients who receive surgery, MD Anderson may recommend giving chemotherapy as well as part of multi-modality treatment. However, it is highly recommended that patients consider enrollment onto a clinical trial which will provide surgery, radiotherapy, chemotherapy and a biologic targeted agent. Your physicians will recommend a clinical trial if it is appropriate.
In patients who are not surgical candidates, the usual treatment is chemotherapy or a clinical study with a new targeted agent to treat the cancer. Since chemotherapy does not cure mesothelioma, we highly recommend treatment on clinical trials which may use chemotherapy in combination with a new targeted biologic therapy or a biologic agent alone. The current standard practice in the United States (when not on a clinical trial) is to receive treatment with chemotherapy agents cisplatin or carboplatin and pemetrexed (Alimta®). Other chemotherapy drugs that are commonly used include gemcitabine and vinorelbine. However, the future of systemic therapy for mesothelioma will be focused on targeted agents and personalized medicine. Personalized medicine means that the choice of treatment will be based on the individual cancer’s specific genetic/molecular profile.