Treatment & Management of Mesothelioma

Treatment & Management of Mesothelioma

Treatment & Management of Mesothelioma

Medically reviewed by Dr. C.H. Weaver M.D. Medical Editor 9/2018

Treatment of malignant mesothelioma may consist of surgery, radiation therapy, chemotherapy or newer precision cancer medicines used alone or in combination.

Generally patients with stage I-III disease have cancer that can potentially be removed with surgery assuming they can withstand the operation

Patients with stage IV or recurrent disease have cancer that cannot be typically removed with surgery because the cancer has spread to the mediastinal, internal mammary, or supraclavicular lymph nodes on the side of the chest opposite to the original cancer. Treatment of stage IV or recurrent mesothelioma is with systemic therapy.

Radiation Therapy for Malignant Mesothelioma

Radiation therapy uses high-energy rays to damage or kill cancer cells by preventing them from growing and dividing. Similar to surgery, radiation therapy is a local treatment used to eliminate or eradicate cancer in a defined area. Radiation therapy is not typically useful in eradicating cancer cells that have already spread to other parts of the body. Radiation may be used to cure or control cancer, or to ease some of the symptoms caused by cancer.

Since malignant mesothelioma spreads widely throughout the pleura and adjacent lung, it is generally impossible to administer the doses of radiation necessary to kill all of the cancer without severely damaging normal tissues and causing significant side effects. In the treatment of malignant mesothelioma, radiation therapy is typically administered:

  • In addition to surgery for patients with stage I-III disease (adjuvant radiation)
  • In addition to surgery and chemotherapy for patients with stage I-III disease (adjuvant radiation and chemotherapy)

To reduce (palliate) the signs and symptoms of the cancer in patients with stage IV disease (radiation for palliation).

Radiation Therapy Delivery. Radiation therapy is delivered to the site of mesothelioma from a machine outside the body, a technique that is called external beam radiation therapy (EBRT). Treatments are typically given daily over a 5-6 week period and additional concentrated radiation treatment, called a boost, may be given directly to a smaller area where the cancer was found.

Adjuvant Radiation Therapy is therapy given following surgical treatment. Adjuvant radiation therapy may be given to patients with stage I-III disease at high-risk for relapse. Researchers from Memorial Sloan-Kettering Cancer Center have shown that adjuvant radiation therapy can dramatically reduce the rate of local cancer recurrence in patients with malignant mesothelioma. In their study, adjuvant radiation improved the survival of patients with early-stage disease.(1)

Adjuvant Radiation and Chemotherapy. The lack of any single consistently curative treatment for malignant pleural mesothelioma has led to the development of multi-modality therapy, including surgery, radiation therapy, and chemotherapy. When radiation and chemotherapy are administered after surgery, they are called adjuvant therapies. Research suggests that patients in good condition with stage I-III malignant pleural mesothelioma should be treated with adjuvant chemotherapy and radiation therapy.

Researchers from the Dana Farber Cancer Center in Boston, MA have reported that among 120 patients with malignant pleural mesothelioma who underwent surgery with extrapleural pneumonectomy and adjuvant treatment with chemotherapy, and radiotherapy, 22% survived 5 years or longer. Patients with epithelial type cancer and those with no lymph node involvement lived longest. On average, patients with stage I disease survived 22 months, compared to 17 months for stage II disease and 11 months for stage III disease.(2)

Italian researchers have also reported that 21 of 27 patients with stage I-III malignant pleural mesothelioma treated with surgery followed by adjuvant chemotherapy and radiation therapy, survived more than a year after treatment.(3)

Radiation for Palliation. Because mesothelioma is sensitive to radiation therapy it can be used to treat local areas of cancer with the intent of reducing symptoms caused by the cancer.(4) Administration of radiation therapy in order to reduce pain, improve breathing, or relieve other side effects caused by the cancer is referred to as palliation.

Side Effects of Radiation Therapy. One of the problems with radiation therapy for malignant pleural mesothelioma is that the cancer is usually widespread, requiring a large area to be radiated. The high doses of radiation necessary for eradication of disease may cause sunburn like changes to the skin, fatigue, and damage normal structures in the chest. Complications of radiation therapy for malignant pleural mesothelioma include inflammation of the lungs (pneumonitis), inflammation of the sack around the heart (pericarditis), and compression of the heart (cardiac tamponade).(5)

Systemic Therapy

Systemic therapy is any treatment directed at destroying cancer cells throughout the body, and may include chemotherapy or newer precision cancer medicines or immunotherapy. Systemic cancer treatment is administered to decrease the risk of cancer recurrence that occurs following treatment with surgery or radiation

Chemotherapy: Chemotherapy uses medications that can be taken orally as a pill or are injected into a vein to kill cancer cells. In some situations chemotherapy is combined with immunotherapy or other precision cancer medicines to achieve the best results.

Precision Cancer Medicine. The purpose of precision cancer medicine is to define the genomic alterations in the cancers DNA that are driving that specific cancer. Cancer used to be diagnosed solely by a visual microscopic examination of tumor tissue and all patients received the same chemotherapy. Precision cancer medicine utilizes molecular diagnostic and genomic testing including DNA sequencing, to identify cancer-driving abnormalities in a cancer’s genome. Once a genetic abnormality is identified, a specific targeted therapy can be designed to attack a specific mutation or other cancer-related change in the DNA programming of the cancer cells. Precision cancer medicine uses targeted drugs and immunotherapies engineered to directly attack the cancer cells with specific abnormalities, leaving normal cells largely unharmed.

By testing an individual’s cancer for specific unique biomarkers doctors can offer the most personalized treatment approach utilizing precision medicines.

Checkpoint Inhibitors are a new precision cancer medicine designed to free the body’s immune system to fight back against cancer. Keytruda (pembrolizumab) appears to be effective in the treatment of the most common form of mesothelioma, according to a study led by investigators from the Perelman School of Medicine at the University of Pennsylvania. The study, published in The Lancet Oncology, is the first to show a positive impact from checkpoint inhibitor immunotherapy drugs in mesothelioma.(5)

Doctors administered Keytruda to 25 patients with pleural mesothelioma who had either already been treated with chemotherapy or were unable to receive it. Patients who had already received another checkpoint inhibitor were not included in the study. The tumor reduced in size in 14 of those patients. On average, patients went about six months without their disease progressing, and overall survival was about 18 months. There are multiple studies going on right now to confirm these findings and confirm the utility of Keytuda and other checkpoint inhibitors and precision cancer medicines in order to improve the survival of individuals with malignant mesothelioma.(5)

References:

  1. Rusch VW, Rosenzweig K, Venkatraman E, et al. A phase II trial of surgical resection and adjuvant high-dose hemithoracic radiation for malignant pleural mesothelioma. J Thorac Cardiovasc Surg 2001;122:788-95.
  2. Sugarbaker DJ, Garcia JP, Richards WG. Extrapleural pneumonectomy in the multimodality therapy of malignant pleural mesothelioma. Results in 120 consecutive patients. Ann Surg 1996; 224:288-94.
  3. Maggi G, Casadio C, Cianci R, et al. Trimodality management of malignant pleural mesothelioma. Eur J Cardiothorac Surg 2001;193:346-50.
  4. Bissett D, Macbeth FR, Cram I. The Role of Palliative Radiotherapy in Malignant Mesothelioma. Clinical Oncology 1991; 3:315-317.
  5. https://www.pennmedicine.org/news/news-releases/2017/march/Keytruda-shows-promise-in-treatment-of-mesothelioma
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