Treating Sarcomatoid Mesothelioma as a Sarcoma

With sarcomatoid mesothelioma, some physicians prefer to treat this type of mesothelioma with sarcoma chemotherapy and subsequent surgery.

Sarcoma is a cancer of the connective tissue. The connective tissue includes muscle, bone, fat, nerve, cartilage, blood vessel, and deep skin tissue. Connective tissue is present throughout the body, so sarcoma can occur in any location. Two thirds of sarcomas are located in the extremities (arms or legs). Because it is so rare and it takes multiple forms in multiple locations, sarcoma is difficult to detect, often misdiagnosed and complex to treat.

According to the American Cancer Society, 1 in 2 men and 1 in 3 women will be diagnosed with cancer in their lifetime. Over 1.3 million people in the United States will be diagnosed with cancer in the year 2003. Fewer than 1% of these people will have sarcoma. In other words, sarcoma is a very rare disease. About 11,000 people will be diagnosed with sarcoma this year, and approximately 50% will be men and 50% women. More than half of these people will be over the age of 60. Sarcomas are more common among childhood cancers, accounting for 15% of those diagnosed per year.

Sarcoma cancers are considered to be rare and unusual in that they can occur in any site of the human body. There are more than fifty different types of soft-tissue sarcomas and sarcoma-like growths. Though rare, exposure to toxic chemical agents is a considered factor that has been associated with soft-tissue sarcomas. Treatments for sarcoma cancers include surgery, chemotherapy and radiation.

Typically, when a sarcoma appears to be fast moving and large in size, chemotherapy is considered to the primary treatment before surgery. The administration of the chemotherapy drugs can be oral or intravenous. These drugs quickly enter the bloodstream reaching all parts of the body, making chemotherapy the best treatment for cancer that has spread or metastasized to other parts of the body.

The drugs used for sarcoma cancers are ifosfamide (IFEX®) and doxorubicin (Adriamycin®). Dacarbazine, methotrexate, vincristine (Ovcovin®), cisplatin, paclitaxel and others are often used in combination. When chemotherapy is used as the treatment prior to surgery, it is done so to slow the course of the cancer or shrink the tumor allowing surgical removal of the entire cancer and a rim of surrounding normal tissue where possible. In some cases, when both doxorubicin and ifosfamide are used together, the likelihood of shrinking a sarcoma almost doubles.

You may have heard of a drug called Glivec or imatinib. This is not a chemotherapy drug. It is a type of drug called a tyrosine kinase inhibitor. This means it blocks a chemical (an enzyme) that the cancer needs in order to grow. Glivec is used to treat a very particular type of soft tissue sarcoma, called a gastro-intestinal stromal tumour or GIST. These are mostly found in the stomach. Glivec is used to treat GISTs that

  • Cannot be removed with surgery

  • Have spread

  • Have come back since they were first treated

Chemotherapy works by killing fast-growing cells. Cancer cells are fast-growing cells. Hair follicles are also fast-growing which is the reason for the typical side effect of hair loss. Other side effects can include nausea and vomiting, loss of appetite and mouth sores. Anti-nausea and appetite stimulation drugs are now available to combat these side effects.

If the high-risk sarcoma responds to chemotherapy, surgery then becomes an option. When treating patients with a sarcoma in the abdominal or peritoneal cavity, surgically directed chemotherapy known as heated intraoperative intraperitoneal or intraperitoneal hyperthermic chemotherapy (IPHC), inserted directly into the abdomen can improve the patient's survival rate and quality of life. The heat increases the chemotherapy penetration into tissues and decreases the drug resistance.

Brachytherapy for a soft-tissue sarcoma can be administered two different ways. After the surgical removal of the tumor the surgeon inserts catheters into the tumor bed. Once the surgical wound has healed, the radiation oncologist inserts radioactive seeds into each catheter and high doses of radiotherapy is delivered to the site for approximately five days. The second form of treatment, called high-dose-rate intraoperative radiation therapy is delivered during the surgery. After removal of the tumor, applicators are placed against the surface of the tumor site and a high dose is directed to the site.

External-beam radiation is delivered from outside the body and focuses on the region of the tumor and surrounding tissues. This type of treatment is usually given after surgery and is most useful for the retroperitoneum and chest. This treatment period is typically five days a week for seven to eight weeks.

Intensity modulated radiation therapy (IMRT) is a sophisticated computer-guided technique that allows safe delivery of much higher doses of radiation to the tumor, sparing the surrounding normal tissue. Used before surgery, IMRT shrinks the tumor, increases the surgical success rate and reduces the chance of recurrence. IMRT is also used on tumors that a close to the spine and major blood vessels.

When diagnosing a mesothelioma, there are considered to be three histopathologic patterns; epithelial, sarcomatoid and biphasic.

An epithelial mesothelioma is composed of sheets and nests of variably atypical epithelioid cells with an obvious stromal invasion. Papillary or tululopapillary growth patterns may also be seen.

A sarcomatoid mesothelioma is composed of cytologically malignant fusiform (spindle-shaped, tapering at both ends) cell proliferations that often imitate sarcomas. These tumor cells have scant cytoplasm, elongated nuclei and scattered mitotic figures.

Biphasic mesothelioma is a combination of both the epithelial and sarcomatoid patterns.

Because the characteristics of a sarcomatoid mesothelioma mimic those of some sarcomas, a sarcomatoid mesothelioma is considered difficult to treat.

It is suggested, that a sarcomatoid mesothelioma might be more receptive if the standard chemotherapy treatment protocol for sarcomas considered to be high-risk and aggressive is first administered. If successful, surgical treatment followed by radiation may become a viable option.

For more information regarding sacro treatments, please visit the Sarcoma Alliance web site: http://www.sarcomaalliance.com/

Sarcoma Centers

The following is a list of some of the medical centers and hospitals specializing in sarcoma. While the list is not comprehensive, it includes the leaders in sarcoma research and treatment. Because sarcomas are rare it is important to find physicians who have experience with this disease. We hope the following list makes finding a specialist easier to accomplish.

Dana Farber Cancer Institute
(Boston, Massachusetts)
http://www.dana-farber.net/pat/adult/treatment/diagnosis_page.asp?ref=dropdown&type=adult&disease=sarcoma
(617) 632-3000

H. Lee Moffitt Cancer Center and Research Institute at the University of South Florida
(Tampa, Florida)
http://www.moffitt.usf.edu/prevention_and_treatment/clinical_programs/sarcoma/
New patient appointments 888-860-2778

Massachusetts General Hospital (MGH)
(Boston, Massachusetts)
http://www.mgh.harvard.edu
Patient information 617-726-2070

M.D.Anderson Cancer Center (MDACC)
(Houston, Texas)
http://www.mdanderson.org/Care_Centers/Sarcoma
New patient referral 713-792-6161

Memorial Sloan-Kettering Cancer Center (MSKCC)
(New York, New York)
http://www.mskcc.org/mskcc/html/435.cfm
Physician Referral Service 1-800-525-2225

Seattle Cancer Care Alliance
(Seattle, Washington)
http://www.seattlecca.org/patientsandfamilies/adultCare/clinicalProgs/sarcoma
206-288-1024

University of Michigan Comprehensive Cancer Center
(Ann Arbor, Michigan)
http://www.cancer.med.umich.edu/clinic/sarclinic.htm
University of Michigan Cancer AnswerLine 1-800-865-1125

Other Sarcoma Centers

Washington Cancer Institute
(Washington DC)
http://www.sarcoma.org

Cedars Sinai Sarcoma Page
(Los Angeles, CA)
http://www.cedars-sinai.edu/850.html

Columbia Presbyterian Sarcoma Program
(New York, New York)
http://hora.cpmc.columbia.edu/dept/medicine/sarcoma/indexorig.html

The Cleveland Clinic Taussig Cancer Center Sarcoma Page
(Cleveland, Ohio)
http://www.clevelandclinic.org/cancer/what/sarcoma.htm

UCLA's Jonsson Comprehensive Cancer Center
(Los Angeles, CA)
http://cancer.mednet.ucla.edu

University of Utah Huntsman Cancer Institute Sarcoma Service
(Salt Lake City, UT)
http://www.hci.utah.edu/group/sarcomaPCMC/introduction.jsp

University of Minnesota Cancer Center
(Minneapolis, MN)
http://www.cancer.umn.edu/page/clinical/bone.html

Fox Chase Cancer Center
(Philadelphia, Pennsylvania)
http://www.fccc.edu/clinical/sarcomas

Roswell Park Cancer Institute
(Buffalo, New York)
http://www.roswellpark.org/Document.asp?lid=4490

*** POSTED APRIL 20, 2005 ***