Mesothelioma is an aggressive disease that often requires an equally aggressive treatment strategy. However, mesothelioma is resistant to many standard cancer treatments, making it a difficult disease to manage.
Most often a treatment plan consists of chemotherapy. For patients who are candidates, surgery and radiation will also be used in a multi-modal approach. Patients should work closely with their medical team to develop a treatment plan that is tailored to their needs and treatment goals.
Even though there is no cure for mesothelioma, treatment strategies are referred to as either curative or palliative in intent. Curative treatments attempt to cure or control the disease, while palliative care is aimed at relieving symptoms and keeping the patient comfortable and surrounded by loved ones without treating the cancer itself.
Mesothelioma treatment options include:
Not all patients are good candidates for surgery. In addition to the patient’s general health, the stage and type of disease help drive the oncologist’s decision to operate. The two primary curative surgeries for mesothelioma patients are pleurectomy/decortication and extrapleural pneumonectomy (EPP).
- Pleurectomy/decortication (P/D). This surgery is sometimes referred to as the “lung-sparing” surgery. The surgery involves stripping away the diseased membrane lining the lung and visible mesothelioma tumors while saving the lung.
- Extrapleural pneumonectomy (EPP). EPP is the alternative to P/D for pleural mesothelioma patients. This surgery is considered a more radical procedure that involves removal of a lung, the diseased lining of the chest cavity and heart, and a portion of the diaphragm.
Palliative surgical procedures focus on relieving symptoms that are impacting a patient’s quality of life, but they do not focus on curing the cancer. Debulking pleurectomy and pleurodesis are two procedures often used in conjunction to improve the breathing for a patient. The pleurectomy eases pressure on the lungs by stripping cancer cells from the pleura. A pleurodesis is then performed to fuse the pleura and limit fluid build-up.
Chemotherapy is one of the primary treatment modes for mesothelioma. Chemotherapy, a strong medicine used to kill cancer cells, is delivered via an infusion in cycles over a period of several months. Unfortunately, chemotherapy drugs don’t distinguish between cancerous and normal cells, and they kill off healthy cells as well. As a result, patients who undergo chemotherapy commonly experience side effects, including anemia, nausea or other digestive disruption, and hair loss.
The most common chemotherapy treatment for mesothelioma is the combination of Alimta (pemetrexed), which was approved by the U.S. Food & Drug Administration in 2004, and cisplatin, a long- standing staple of many chemo treatments.
Radiation therapy uses high-energy ionizing radiation to kill cancer cells. Ionizing radiation changes the structure of DNA in cells, thus inhibiting growth and division. Radiation is used in most cases of mesothelioma. However, pinpointing the malignant cells is difficult, resulting in damage to healthy cells as well. The side effects of radiation are similar to those for chemotherapy and include hair loss, digestive problems, and anemia.
Recent breakthroughs in the use of proton therapy, which uses a beam of protons to irradiate the tumors, as opposed to X-ray beams used in conventional radiation therapy, are allowing physicians to target deep-seated tumors with greater precision, limiting damage to the surrounding tissue.
Mesothelioma Alternative Treatments
“Immunotherapy is a new class of cancer treatment that works to harness the innate powers of the immune system to fight cancer,” according to the Cancer Research Institute. Recharging the body’s own defense mechanism, the immune system, immunotherapy may hold greater potential than current treatment approaches:
- To fight cancer more powerfully,
- To offer longer-term protection against the disease,
- To come with fewer side effects, and,
- To benefit more patients with more cancer types.
Keytruda is one immunotherapy treatment that has led the news recently. Not only have several long-term mesothelioma survivors seen great benefits from this drug, but 91-year-old, former US president Jimmy Carter announced the drug helped him beat melanoma that had metastasized to his liver and brain.
The drug, developed by Merck, suppresses the PD-L1 biomarker found in cancer cells. PD-L1, or programmed death-ligand 1, is a protein that has been shown to play a role in suppressing the immune system during cancer and other diseases.
Opdivo, developed by Bristol-Myers Squibb, is another FDA-approved lung cancer, immunotherapy drug that works by blocking the PD-L1 protein and activating the immune system. Except for the dosing differences, Opdivo and Keytruda are comparable, according to reports.
SMART Treatment Promising
The ‘Surgery for Mesothelioma After Radiation Therapy’ study, conducted by researchers at Princess Margaret Cancer Center in Toronto, more than doubled three-year survival rates of mesothelioma patients who underwent radiation therapy followed within a week of an extrapleural pneumonectomy surgery to remove the lung. The survival rates improved to 72%, from 32%, and the patients experienced “shorter treatment, fewer complications and speedier recovery,” according to Dr. John Cho, radiation oncologist and partner in the study.
The SMART approach also reduced the risk of recurrence, according to the researchers, because the radiation halted the mesothelioma cancer cells ability to seed itself elsewhere in the chest or abdomen during surgery.
“These research results offer real hope to mesothelioma patients who have too often been told in the past that they may have only six months to live,” say the researchers.
Since the study was published in 2014, the physicians have used the SMART approach to successfully treat at least 20 more patients.
According to the National Institutes of Health, clinical trials are at the heart of all medical advances. Clinical trials serve to uncover better ways to treat, prevent, diagnose and understand human disease. They provide mesothelioma researchers with critical information needed to allow them to move their findings from the lab to patients. For some mesothelioma patients, clinical trials offer an opportunity to try a treatment that is not otherwise available.
There are benefits and risks to participating in clinical trials. In the U.S., clinical trials are closely monitored and are run according to strict guidelines. The NIH explains that federally funded clinical research has safeguards in place to protect the participants. Deciding whether to enter into a clinical trial is a patient’s personal choice, and the benefits and risks should be carefully weighed.
Mesothelioma patients are encouraged to work closely with their doctors to determine the best treatment plan for their needs. The treatment plan you and your doctor develop will depend on several factors, including the type and stage of disease, and your overall health.
Mesothelioma is one of the most aggressive cancers, and, as a result, is one of the most challenging to treat. Surgery, chemotherapy and radiation are the primary treatment protocols; however, while these treatments can relieve symptoms, they do little to improve survival. When patients are diagnosed with the terminal cancer, they are often given just a year to live.
Recent breakthroughs in cancer research in general have meant an improvement in survival of mesothelioma patients.
Patients in clinical trials often have higher survival as they benefit from the current research to bring new, effective treatments to patients. Mesothelioma patients in clinical trials have access to treatments that may not otherwise be available to them.
Some clinical trials making headlines include:
CRS-207 Shows “Impressive” Results
Aduro-Biotech announced early findings of its multi-center, Phase 1b mesothelioma clinical trial designed to assess the efficacy of CRS-207 when used in combination with chemotherapy drugs pemetrexed and cisplatin for patients with malignant pleural mesothelioma. Initial results of 38 patients included disease control in 94% of the patients, 59% with partial response and 35% experiencing stable disease following treatment with CRS-207 and chemotherapy.
“The data in this trial continue to be impressive in the front-line treatment of mesothelioma,” reports the researchers.
CRS-207, an immunotherapy drug that has been engineered to express the tumor-associated antigen mesothelin, which is over-expressed in mesothelioma, has gained orphan drug designation from the U.S. Food and Drug Administration.
Triplet Therapy for Mesothelioma
The French Cooperative Thoracic Intergroup report results from its randomized Phase 3 trial, where patients with mesothelioma were treated with the combination chemotherapy regimen of pemetrexed/cisplatin with or without bevacizumab (Avastin), saying the trial resulted in “a significantly longer survival” for patients receiving bevacizumab with pemetrexed/cisplatin.
The results are so impressive that the study authors are saying, “The treatment of pemetrexed, cisplatin, and bevacizumab is a new treatment paradigm for patients with malignant pleural mesothelioma.”
If you find a clinical trial that you believe will benefit you, talk to your doctor. For a complete list of current mesothelioma clinical trials see ClinicalTrials.gov.
Q&A: Latest Treatments for Mesothelioma
Researchers are studying whether chemotherapy before surgery and radiation can deter tumor recurrence in patients with mesothelioma, a rare cancer of the lining of the chest caused by asbestos exposure.
The study builds on the success of a previous clinical trial at M. D. Anderson that included surgery called extra pleural pneumonectomy (EPP), which involves removal of the affected lung and lining of the chest, followed by a highly specialized form of radiation therapy known as Intensity Modulated Radiotherapy (IMRT).
The new multi-center study, which will recruit 77 patients nationwide, will involve EPP, post-operative IMRT and the chemotherapy drugs pemetrexed (Alimta®) and cisplatin, says Katherine Pisters, M.D., principal investigator on the study at M. D. Anderson and associate professor in the Department of Thoracic/Head and Neck Medical Oncology.
The other trial locations are:
- Memorial Sloan-Kettering Cancer Center, New York
- University of Chicago, Chicago
- Johns Hopkins Hospital, Baltimore
- Barbara Ann Karmanos Cancer Institute, Detroit
- University of Pennsylvania, Philadelphia
- Brigham and Women’s University, Boston
Many of the sites already have begun studying the use of chemotherapy prior to surgery and radiation. The chemotherapy combination of pemetrexed and cisplatin was approved by the Food and Drug Administration (FDA) for treatment of mesothelioma after the drugs were shown to prolong survival.
Answering questions about both studies are Pisters, Craig Stevens, M.D., Ph.D., principal investigator on the previous M. D. Anderson trial and associate professor in the Division of Radiation Oncology; and David Rice, M.D., surgical principal investigator on the new study and assistant professor in the Department of Thoracic and Cardiovascular Surgery.
What is unique about this study?
Pisters: This is the first mesothelioma trial to explore the use of chemotherapy before surgery and radiation.
How does the new trial build on the previous study?
Stevens: Our previous trial involving extrapleural pneumonectomy and IMRT was more than 90% effective in preventing a local recurrence (return of the cancer to its original site). However, 50% of those patients experienced recurrence in a different location, usually the other lung, abdomen or another part of the body. M. D. Anderson will be the only center employing IMRT rather than conventional radiation therapy.
Pisters: We are now adding chemotherapy before surgery and radiation to decrease the possibility of distant cancer metastasis (spread to an area away from the original site). We are using pemetrexed and cisplatin because they already have been shown to be effective in metastatic disease.
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