Soft Tissue Sarcoma. Presley Regional Trauma Center Department of Surgery University of Tennessee Health Science Center Memphis, Tennessee

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1 Soft Tissue Sarcoma Presley Regional Trauma Center Department of Surgery University of Tennessee Health Science Center Memphis, Tennessee

2 Soft Tissue Sarcoma Collective term for an unusual and diverse group of malignancies that arise from cells of the embryonic mesoderm Account for 1% of adult and 15% of pediatric tumors Comprise more than 50 distinct histologic subtypes

3 Soft Tissue Sarcoma May occur anywhere in the body 43% - extremities 15% - RP 10% - trunk 19% - viscera 13% - other

4 Etiology Unclear and controversial Genetic factors Chemical exposure Lymphedema

5 Etiology Chromosomal abnormalities - Translocations - Point mutations - Deletions Regulatory genes - p53 - RB1

6 Etiology Ionizing radiation - Often do not become clinically apparent until long after inciting exposure - Osteosarcoma - Malignant fibrous histiocytoma Chemical carcinogenesis - Thorotrast - Vinyl chloride - Arsenic

7 Pathologic Classification

8 STS Categorized on the basis of the tissue type from which it is believed to originate Subtypes may be defined by histochemistry, flow cytometry, EM, tissue culture and cytogenetic analysis Useful in determining which therapy is best not part of staging system

9 Grade Best indicator of biologic aggressiveness and metastatic potential Defined by tumor s cellularity, nuclear atypia, degree of necrosis and mitotic activity AJCC staging system integrates tumor grade, size, depth of tissue invasion, degree of nodal involvement and mets

10 Clinical Evaluation

11 Presentation Asymptomatic mass Painless and large Often noticed because of h/o recent trauma to the area 38% are > 10 cm

12 Presentation Distant mets vary with tumor histology and site of primary Extremity lung Abdominal and RP liver Few go to regional LN (2.6%)

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14 Management

15 Surgical Therapy Foundation of treatment Amputation was once considered the only option for cure Rosenberg et al (1982) Amputation is usually reserved for extremity sarcomas that involve major vessels, nerves or bones

16 NCI Rosenberg et al (1982) - 43 patients with extremity sarcoma - Amputation (n = 16) - Limb-sparing surgery + radiation (n = 27) - All received adjuvant chemotherapy - 5-year local recurrence slightly higher in LSS - 5-year survival nearly identical

17 Surgical Therapy Adequate resection involves excising a margin of normal tissue along with any areas through which biopsies have been performed Compartmental resection or resection of entire muscle groups provides no benefit over WLE 1 to 2 cm margin should be the goal

18 Surgical Therapy Regional lymphadenectomy is not usually indicated Tumor is in proximity to a LN basin Tumor is one of the following subtypes - Rhabdomyosarcoma - Epithelioid sarcoma - Clear cell sarcoma - Synovial sarcoma - Vascular sarcoma

19 Sarcoma Type Incidence of Nodal Metastases (%) Rhabdosarcoma Epithelioid Sarcoma Clear Cell Sarcoma Synovial Sarcoma 2-17 Vascular Sarcoma 11-40

20 Radiation Therapy Dramatically changed the surgical treatment of sarcomas Provides local control Brachytherapy Post-, pre-operative external beam

21 Brachytherapy MSKCC pts with extremity or superficial trunk sarcoma - Resection ± brachytherapy - 76 month median f/u - Local control rate better in BT group - No difference in 5-year disease-specific survival

22 External Beam NCI - 91 pts with high-grade STS - Resection ± radiation - All pts received adjuvant chemotherapy - One local recurrence with radiation vs 8 with no radiation - No difference in overall survival

23 Pre- vs Post-op External Beam Canada pts - Closed because of wound complications - Pre-op = 35% vs 17% with post-op - No difference in local control - Significant difference in overall survival that slightly favored the pre-op group

24 Chemotherapy Post-op chemo has been studied in multiple prospective, randomized trials but small sample sizes and differences among them have made it difficult to interpret the data Sarcoma Meta-analysis Collaboration Post-op adjuvant chemotherapy is best employed in the context of appropriate clinical trials

25 Pre-op Chemotherapy Allows delivery of agents through native vasculature Permits assessment of effectiveness of tx by pathologic analysis May facilitate tx of micromets May downstage tumors making them more amenable to resection

26 Conflicting Data MD Anderson - Retrospective, 46 pts extremity sarcomas - Overall tumor response rate was 40% - Significant improvement in both disease-free and overall survival MSKCC - Prospective, 29 pts - Large, high-grade extremity sarcomas - No benefit

27 Conclusion Given the lack of sufficient evidence for any survival benefit, pre-op chemotherapy may be considered in attempting to preserve limb function but otherwise its use should be limited to clinical trials

28 Targeted Therapeutics Most interesting and exciting advances The characterization and targeting of the tyrosine kinase receptor = c-kit GIST

29 Isolated Limb Perfusion Reserved for patients in whom LSS is not possible Cannulate the arterial and venous supply and apply a proximal tourniquet Bypass machine maintains mild hyperthermia, oxygenation and circulates chemotherapeutic agents in the limb

30 Recurrent STS Extremity - local recurrence = 8 to 20% RP - local recurrence = 38 to 50% Salvage surgery is an option Radiation for those who did not receive it previously

31 Metastatic Disease

32 Resectable Lung mets present in 20% of pts with trunk or extremity Resection may be attempted if pt is medically fit, no extrathoracic disease is present and the primary tumor is controlled 3-year survival ranges from 23 to 54%

33 Unresectable Distant mets may develop in as many as 50% of cases For the vast majority, only available treatment option is systemic chemotherapy Doxorubicin