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soft tissue sarcoma (STS)

Epidemiology: 1) malignant fibrous histiocytoma 40% 2) liposarcoma 25% Pathology: histologic grade (number of mitoses, degree of cellularity & nuclear atypia, presence of necrosis) reflects metastatic potential more accurately than specific cell type Microscopic Pathology: (classification): - alveolar soft part sarcoma - desmoplastic small round cell tumor - epithelioid sarcoma - clear cell sarcoma - chondrosarcoma, extraskeletal - osteosarcoma, extraskeletal - gastrointestinal stromal tumor - Ewing's sarcoma/primitive neuroectodermal tumor - fibrosarcoma - leiomyosarcoma - liposarcoma - malignant fibrous histiocytoma - malignant hemangiopericytoma - malignant peripheral nerve sheath tumor - rhabdomyosarcoma - synovial sarcoma - sarcoma NOS (not otherwise specified) Genetics: - amplification of MDM2 Radiology: - MRI with contrast with or without CT with contrast [3] Staging: TNM classification/grading - primary tumor (T) - TX: primary tumor cannot be assessed - T0: no evidence of primary tumor - T1: tumor ~ 5cm in greatest dimension - T1a: superficial tumor - T1b: deep tumor - T2: tumor > 5cm in greatest dimension - T2a: superficial tumor - T2b: deep tumor - regional lymph nodes (N) - NX: regional lymph nodes cannot be assessed - N0: no regional lymph node metastases - N1: regional lymph node metastasis * regional lymph nodes metastasis is rare and cases NX can be considered N0 - distant metastases (M) - MX: distant metastasis cannot be assessed - M0: no distant metastasis - M1: distant metastasis histopathologic grading (G) GX: grade cannot be assessed G1: well differentiated G2: moderately differentiated G3: poorly differentiated G4: poorly differentiated or undifferentiated stage T N M G G Risk stage I T1a,1b,2a,2b N0 M0 G1-2 G1 low stage II T1a,1b,2a N0 M0 G3-4 G2-3 high stage III T2b N0 M0 G3-4 G2-3 high stage IV T_ N1 M0 G_ G_ low or high T_ N0 M1 G_ G_ low or high Management: - surgery: - goal: functional limb preservation [3] - amputation may be necessary in some patients - re-resection is preferred for patients with positive surgical margins - external-beam RT (EBRT) with intensity-modulated RT (IMRT) &/or proton therapy - adjunct to surgical resection - not a substitute for suboptimal surgical resection [3] - preoperative RT: 50 Gy in 1.8 to 2.0 Gy per fraction - EBRT boost doses of 16-18 Gy for microscopic residual disease & 20-26 Gy for macroscopic residual disease. [3] - brachytherapy boosts delivered several days after surgery, through catheters placed at surgery - doses of 14-26 Gy, based on surgical margin status - chemotherapy: anthracyclines 1st line [4] - doxorubicin + ifosfamide - doxorubicin + olaratumab is an option - imatinib in patients with dermatofibrosarcoma protuberans - trabectedin (2nd line) - pazopanib is an option in non-adipogenic STS. - eribulin is an option in patients with liposarcomas & leiomyosarcomas - dacarbazine/gemcitabine or docetaxel/gemcitabine is an option in doxorubicin-pretreated patients - regorafenib is an option in doxorubicin-pretreated advanced, non-adipogenic STS patients [4]

Interactions

disease interactions

Specific

alveolar soft part sarcoma clear cell sarcoma desmoplastic small round cell tumor (DSRCT) Ewing's sarcoma gastrointestinal stromal tumor (GIST) hemangiosarcoma; angiosarcoma Kaposi's sarcoma leiomyosarcoma liposarcoma lymphangiosarcoma malignant fibroblastic/myofibroblastic neoplasm malignant fibrous histiocytoma (MFH, angiomatoid fibrous histiocytoma) malignant peripheral nerve sheath tumor (MPNST) rhabdomyosarcoma (Sarcoma Botryoides) synovial sarcoma

General

sarcoma soft (connective) tissue neoplasm

References

  1. WHO Classification Tumours of Soft Tissue and Bone Fletcher, Unni & Mertens Eds. IARC Press 2002
  2. AJCC Cancer Staging Manual 6th ed. Springer 2002
  3. Von Mehren M, Randall RL, Benjamin RS, et al. Soft Tissue Sarcoma, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw. 2018 May;16(5):536-563. PMID: 29752328 http://www.jnccn.org/content/16/5/536.long
  4. Casali PG, Abecassis N, Bauer S, et al. Soft tissue and visceral sarcomas: ESMO-EURACAN Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. May 28, 2018. PMID: 29846498 https://academic.oup.com/annonc/advance-article/doi/10.1093/annonc/mdy096/5004451
  5. National Cancer Institure Soft Tissue Sarcoma - Health Professional version https://www.cancer.gov/types/soft-tissue-sarcoma/hp