Adam The 2013 statistics for soft tissue sarcomas estimate that there will be about 11,410 new cases (6,290 in males, 5,120 in females) in the U.S. 4,390 people are expected to die of these sarcomas (2,500 males, 1890 females).1
The most common types are malignant fibrous histiocytomas, liposarcomas, and leiomyosarcomas.1
Etiology:
Megan In general the causes for soft tissue sarcomas (STS) are unknown. Kaposi's Sarcoma however, does have a known causative agent. It occurs in people with defective immune systems and is caused by a virus known as human herpes virus 8. Some STSs can be linked to heredity. Radiation exposure such as the treatment used for lymphoma or breast cancer have been linked to a possibility of STS development. And high dose exposure to chemicals like vinyl chloride, dioxin, and herbicides.2
Signs & Symptoms:
Kevin Tsai
Abdominal pain or a mass in 60% to 80% of cases3
50% have weight loss and loss of appetite at diagnosis
Patients with sarcomas tend not to seek medical treatment until the tumors are large, because these tumors are usually asymptomatic. Patient with germ cell tumor or lymphoma become more acutely ill
Several retroperitoneal tumors are associated with paraneoplastic syndromes
Germ cell tumors can cause precocious puberty in children, and neuroblastoma can produce opsoclonic myoclonus
Retroperitoneal liposacroma or lipoma can produce intermittent hypoglycemia
Extraadrenal retroperitoneal paraganglioma can produce symptoms of excessive catecholamine
Diagnostic Procedures:
Erin The following is a list of procedures typically done in the diagnosis of soft tissue sarcomas:4
Detailed history
Physical exam
Diagnostic imaging
MRI - imaging modality of choice because of its great soft tissue contrast
PET - useful in diagnosing mets, additional lesions, or lymph node extentions
Chest radiographs & CT - usually performed for complete staging because most soft tissue sarcomas metastasize to the lungs
Bone scans - used to look for other mets
Biopsy - used to identify the histology of the tumor and to provide information in determining the treatment protocol
Histology:
Spencer There are a variety of different types of soft tissue sarcomas:
The histology of retroperitoneal tumors tend to predict the mode of invasion and are also extremely diverse due to the embryologic origin.3 The most common retroperitoneal tumor seen in children is the rhabdomyosarcoma, followed closely by lymphoma.3
Lipoma and Liposarcoma are some of the most common soft tissue sarcoma subtypes, consisting of 25-50% of the cases seen.3
Most children and infants who develop a soft tissue sarcoma will progress to germ cell tumors.3
There is a 60-70% chance of local adjacent organ involvement at the location of the tumor site.3
Lymph node drainage:
Pablo Soft tissue sarcomas do not usually use the lymph node system to metasasize to other parts of the body. Unless the tumor is located in the mediastinum where there is a rich network of lymph nodes, lymphatic spread is not of great concern to physicians.5
Metastatic spread:
Becky
Soft tissue sarcomas tend to spread hematogenously rather than via lymph nodes. The most common site for metastasis is the lung. Some soft tissue sarcomas tend to spread by local extension into surrounding tissue.6
Grading:
Megan Grading determines the likelihood of cancer spread, or metastasis. The system that previously used for grading soft tissue sarcomas (STS) was ineffectual because it was based on how differentiated the cells were from normal. The new system used is the French or FNCLCC system, and the grade is based on the following 3 factors:7
Differentiation — receives a score of 1 to 3, with 1 assigned to cancer cells resembling normal cells and 3 assigned to cells looking abnormally
Mitotic count — how many cancer cells are seen dividing under the microscope; given a score from 1 to 3 (a lower score means fewer cell divisions)
Tumor necrosis — amount of the tumor made up of dying tissue; given a score from zero to 2 (a lower score means there was less dying tissue present).
The scores for each factor are added up to determine the grade for the cancer. Higher-grade cancers tend to grow and spread faster than lower-grade cancers. GX: the grade cannot be assessed (because of incomplete information). Grade 1 (G1): Total score of 2 or 3 Grade 2 (G2): Total score of 4 or 5 Grade 3 (G3): Total score of 6 or higher
Staging:
Adam The staging system for soft tissue sarcomas is as follows:8
Tumor T1 - 5cm or less across
T1a - The tumor is superficial
T1b - The tumor is deep in the limb or abdomen
T2 - Greater than 5cm across
T2a - The tumor is superficial
T2b - The tumor is deep in the limb or abdomen
Lymph nodes N0 - The sarcoma has not spread to nearby lymph nodes. N1 - The sarcoma has spread to nearby lymph nodes.
Metastasis M0 - No distant metastasis M1 - Distant metastasis
Radiation side effects:
Kevin Tsai
Acute sequelae – nausea and vomiting3
Long-term sequelae – small bowel enteropathy, which is linked to the number of laparotomies the patient has had and irradiation dose and volume, and small bowel obstruction
Prognosis:
Erin
The most important prognostic factor for a soft tissue sarcoma is the tumor grade.9
Data collected from Memorial Sloan-Kettering showed that prognostic factors for local recurrence included age > 50 years, reccurent disease at presentation, microscopically positive surgical margins, and the histologic subtypes fibrosarcoma and malignant peripheral-nerve tumors.
For distant recurrence, intermediate tumor size, high histologic grade, deep location, recurrent disease at presentation, leiomyosarcoma, and nonliposarcoma histology were independent adverse prognostic factors.
Treatments:
Spencer
Surgical resection of the soft tissue sarcoma has been the main treatment modality used to help localize and control the disease.3 Surgery would not be an option if there was tumor involvement within the heart region, spinal cord, or if its has already metastasized.3
Radiation therapy is usually given in most cases of malignant retroperitoneal tumors because of how they infiltrate other soft tissue areas.3
Although there is not a wide amount of data due to the numerous amounts of different soft tissue sarcoma sites, the use of chemotherapy in treatment of soft tissue sarcomas is widely given and is often used as the initial treatment modality followed by surgery and radiation therapy.3
TD 5/5:
Pablo The following table is a general list of radiation tolerances for different organs.10
The 2013 statistics for soft tissue sarcomas estimate that there will be about 11,410 new cases (6,290 in males, 5,120 in females) in the U.S. 4,390 people are expected to die of these sarcomas (2,500 males, 1890 females).1
The most common types are malignant fibrous histiocytomas, liposarcomas, and leiomyosarcomas.1
In general the causes for soft tissue sarcomas (STS) are unknown. Kaposi's Sarcoma however, does have a known causative agent. It occurs in people with defective immune systems and is caused by a virus known as human herpes virus 8. Some STSs can be linked to heredity. Radiation exposure such as the treatment used for lymphoma or breast cancer have been linked to a possibility of STS development. And high dose exposure to chemicals like vinyl chloride, dioxin, and herbicides.2
The following is a list of procedures typically done in the diagnosis of soft tissue sarcomas:4
There are a variety of different types of soft tissue sarcomas:
Soft tissue sarcomas do not usually use the lymph node system to metasasize to other parts of the body. Unless the tumor is located in the mediastinum where there is a rich network of lymph nodes, lymphatic spread is not of great concern to physicians.5
Soft tissue sarcomas tend to spread hematogenously rather than via lymph nodes. The most common site for metastasis is the lung. Some soft tissue sarcomas tend to spread by local extension into surrounding tissue.6
Grading determines the likelihood of cancer spread, or metastasis. The system that previously used for grading soft tissue sarcomas (STS) was ineffectual because it was based on how differentiated the cells were from normal. The new system used is the French or FNCLCC system, and the grade is based on the following 3 factors:7
- Differentiation — receives a score of 1 to 3, with 1 assigned to cancer cells resembling normal cells and 3 assigned to cells looking abnormally
- Mitotic count — how many cancer cells are seen dividing under the microscope; given a score from 1 to 3 (a lower score means fewer cell divisions)
- Tumor necrosis — amount of the tumor made up of dying tissue; given a score from zero to 2 (a lower score means there was less dying tissue present).
The scores for each factor are added up to determine the grade for the cancer. Higher-grade cancers tend to grow and spread faster than lower-grade cancers.GX: the grade cannot be assessed (because of incomplete information).
Grade 1 (G1): Total score of 2 or 3
Grade 2 (G2): Total score of 4 or 5
Grade 3 (G3): Total score of 6 or higher
The staging system for soft tissue sarcomas is as follows:8
Tumor
T1 - 5cm or less across
- T1a - The tumor is superficial
- T1b - The tumor is deep in the limb or abdomen
T2 - Greater than 5cm acrossLymph nodes
N0 - The sarcoma has not spread to nearby lymph nodes.
N1 - The sarcoma has spread to nearby lymph nodes.
Metastasis
M0 - No distant metastasis
M1 - Distant metastasis
The following table is a general list of radiation tolerances for different organs.10
1. Key Statistics about Soft Tissue Sarcomas. Cancer.org Web Site. http://www.cancer.org/cancer/sarcoma-adultsofttissuecancer/detailedguide/sarcoma-adult-soft-tissue-cancer-key-statistics. Accessed July 12, 2013.
2. Mayo Clinic Staff. Mayo Clinic website. Causes. http://www.mayoclinic.com/health/soft-tissue-sarcoma/DS00601/DSECTION=causes. Last Modified Sept 13, 2011. Accessed July 12, 2013.
3. Chao KS, Perez CA, Brady LW. Radiation Oncology Management Decisions. 3rd edition. Philadelphia, PA: Lippincott Williams & Wilkins. 2011; 703-718.
4. Washington CM, Leaver D. Principles and Practice of Radiation Therapy. 3rd ed. St Louis, MO: Mosby Inc; 2010:598-599.
5. Washington, CM & Leaver, DT. Principles and Practice of Radiation Therapy. 3rd ed. St. Louis, MO; 2010. P585-588
6. Hosemann S. Stage II or III soft tissue sarcoma. MD Anderson Cancer Center Website. http://www2.mdanderson.org/depts/oncolog/articles/11/6-jun/6-11-compass.html June 2011. Accessed July 3, 2013.
7. American Cancer Society Website. Sarcoma- Adult Soft Tissue Cancer.http://www.cancer.org/cancer/sarcoma-adultsofttissuecancer/detailedguide/sarcoma-adult-soft-tissue-cancer-staging. Last modified Jan 17, 2013. Accessed July 12, 2013.
8. Soft Tissue Sarcoma Staging. Cancer.org Web Site. http://www.cancer.org/cancer/sarcoma-adultsofttissuecancer/detailedguide/sarcoma-adult-soft-tissue-cancer-staging. Accessed July 12, 2013.
9. Chao KS, Perez CA, Brady LW. Radiation Oncology Management Decisions. 2nd ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2002:617-618.
10. Journal of Medical Physics. Web site. http://www.jmp.org.in/article.asp?issn=0971-6203;year=2011;volume=36;issue=4;spage=192;epage=197;aulast=Prabhakar. Accessed July 08, 2013.