Soft Tissue Sarcoma: Causes, Symptoms, Treatment and Prognosis — Overview, Diagnosis & Treatment Options | MyMedicPlus

Soft tissue sarcomas (STS) are malignant tumors of non-epithelial, non-hematopoietic extraskeletal tissue comprising over 50 histological subtypes. The most common include liposarcoma, leiomyosarcoma, undifferentiated pleomorphic sarcoma (UPS), and synovial sarcoma. Approximately 13,000 new cases occur per year in the US.

Most are sporadic with no identifiable cause. Established risk factors: prior radiation therapy (radiation-induced sarcoma after 5-10 year latency), genetic syndromes (Li-Fraumeni/TP53, NF1, retinoblastoma/RB1, FAP/Gardner), chronic lymphedema (Stewart-Treves angiosarcoma post-axillary dissection), and vinyl chloride or herbicide exposure.

Painless or painful enlarging soft tissue mass, typically deep to fascia and greater than 5 cm at diagnosis. Retroperitoneal sarcomas (liposarcoma, leiomyosarcoma) reach very large sizes asymptomatically before presenting with abdominal fullness or compression symptoms. Constitutional symptoms occur in high-grade lesions. Extremity STS is the most common anatomical location (~50%).

MRI of the primary site is the imaging modality of choice for soft tissue tumors. Core needle biopsy performed at a specialist sarcoma center — biopsy tract placement is critical and must not compromise future surgery. Histological subtype, FNCLCC grade, and molecular profiling (FISH and NGS for specific translocations such as SYT-SSX in synovial sarcoma, MDM2 amplification in liposarcoma) are essential. CT chest for pulmonary metastases.

Wide local excision achieving negative (R0) margins is the cornerstone of treatment. Radiation therapy (preoperative 50 Gy or postoperative 60-66 Gy) reduces local recurrence for intermediate- and high-grade extremity and retroperitoneal STS. Chemotherapy (doxorubicin ± ifosfamide) for high-grade, metastatic disease, or neoadjuvant size reduction. Subtype-specific: trabectedin for liposarcoma/leiomyosarcoma, tazemetostat for epithelioid sarcoma, pazopanib for second-line non-adipocytic STS.

Localized low-grade STS: 5-year OS exceeds 85%. High-grade, deep, and larger than 5 cm: 5-year OS approximately 50-60%. Metastatic disease: 5-year OS approximately 15-20%. Histological subtype profoundly impacts prognosis. Management at specialized multidisciplinary sarcoma centers consistently achieves better outcomes than non-specialist settings.