Soft Tissue Sarcoma (STS) – Non-metastatic, Non-GIST, Non-Fibromatosis, non-angiosarcoma
Local control of extremity soft tissue sarcoma:
- The tumour should be carefully assessed using physical examination and radiographic evaluation to assess the size, depth and location of the mass, along with signs of neurovascular involvement are essential for designing the best therapeutic approach.
- Local control refers to the treatment approaches focusing on the primary site of disease. The therapeutic goals of local control are to improve patient survival and minimize or eliminate morbidity associated with the primary tumour. Individual patient and tumour factors will influence management. Risk features include a tumour size of >5cm, deep lesion and high grade disease.
Surgery
- Surgical resection remains the cornerstone of local control in STS.
- The extent of surgical resection has increasingly become histology specific and has generally moved away from overly morbid operations, highlighting the importance of evaluation by a sarcoma surgeon.
- Wide local excision (WLE) alone results in unacceptably high local recurrence rates of 30-50%.
- The use of perioperative radiotherapy significantly reduces local recurrence rates.
- Currently, limb-sparing WLE and Radiation are the standard of care for primary extremity STS.
Radiation Therapy
- Radiation therapy (RT) recommendations depend on a number of factors including histology, tumour size and grade, and the depth of lesion.
- Local control can be improved with perioperative RT in selected patients with extremity STS.
- Radiotherapy may be administered pre- or post-operatively. Both result in similar local control efficacy. There are advantages and disadvantages with either approach.
- Pre-operative radiotherapy allows for a smaller treatment volume and results in lower rates of long-term fibrosis and lymphedema, and improved joint mobility. However, rates of early wound complications are higher.
- With post-operative radiotherapy, definitive surgery is not delayed and there are fewer wound complications. However, a larger treatment volume is required, with potential attendant subsequent long-term radiation associated side effects.
Chemotherapy
- There is currently no consensus on the role of adjuvant chemotherapy. Available evidence from meta-analyses and randomized clinical trials suggest that post-operative chemotherapy improves relapse free survival in patients with extremity sarcoma. However, individual studies of adjuvant chemotherapy have produced mixed results for overall survival benefit. The Sarcoma Meta-analysis collaboration (SMAC) showed a trend in favour of OS advantage for doxorubicin-based adjuvant chemotherapy in patients with extremity sarcoma, which was not statistically significant. An updated meta-analysis reported marginal efficacy in terms of RFS and OS. Thus, while postoperative adjuvant chemotherapy is not routine, it may be considered in selected patients based on a number of factors including age, comorbidities, histologic subtype, size, grade, depth of lesion and resection margin.
Advanced or metastatic soft tissue sarcoma (STS)
- STS most commonly metastasize to the lungs. Tumours arising in the abdominal cavity more commonly metastasize to the liver and peritoneum.
- The decision making in the management of advanced or metastatic STS is complex, depending on diverse presentations and histologies, and should always be multidisciplinary.
- In general, presentation with metastatic disease is considered incurable, and treatment is considered palliative. Chemotherapy usually plays a primary role in the management of metastatic sarcoma. However, there may also be a role for surgery or radiation therapy for palliation to control symptoms and improve quality of life.
- Where lung metastases are synchronous, in the absence of extrapulmonary disease, standard treatment is chemotherapy. Surgery of completely resectable residual lung metastases may be considered as an option, especially when a tumour response is achieved.
- Metachronous resectable lung metastases without extrapulmonary disease are managed with surgery as standard treatment, if complete excision of all lesions is feasible.
- Appropriate imaging should be utilized to exclude extrapulmonary disease. These can include CT or PET scans. The role of chemotherapy in this setting is individualized. Where chemotherapy is added to surgery as an option, it is preferable to give the chemotherapy prior to surgery to assess tumour response and modulate treatment as needed.
- Extrapulmonary metastatic disease is treated with chemotherapy.
- In highly selected cases, surgery of responding metastases may be offered as an option following multidisciplinary evaluation, taking into consideration their site and natural history of the disease in the individual patient.
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Chemotherapy for metastatic /advanced disease: Standard first-line chemotherapy consists of anthracycline-based therapy. Multi-agent chemotherapy has not been found to be superior to Doxorubicin alone in terms of overall survival. However, a higher response rate can be expected, especially in chemo-sensitive subtypes. Thus, in selected patients, the combination of doxorubicin with Ifosfamide could be considered.
- After failure of anthracycline-based chemotherapy, other agents have been shown to be active. been shown to be active (but without high-level evidence) include:
- Gemcitabine with or without docetaxel (leiomyosarcoma, undifferentiated pleomorphic sarcoma, angiosarcoma).
- Taxanes (angiosarcoma)
References
- Crompton, et al. Local control of soft tissue and bone sarcomas. JCO 2018;36(2):111-117.
- O’Sullivan B, Davis AM, Turcotte R, et al: Preoperative versus postoperative radiotherapy in soft-tissue sarcoma of the limbs: A randomised trial. Lancet 359:2235-2241, 2002
- Haas RL, Gronchi A, Van de Sande MAJ, et al: Perioperative management of extremity soft tissue sarcoma. JCO 2018:36(2): 118-124
- Soft tissue and visceral sarcomas: ESMO Clinical Practice Guidelines for diagnosis, treatment and followup. The ESMO/European sarcoma network working group. Annals of onc 2014;25 (Suppl. 3): iii102-iii12
- Judson I, Gelderblom H, Schoffski P, t al. Doxorubicin alone versus intensified doxorubicin plus ifosfamide for first-line treatment of advanced or metastatic soft-tissue sarcoma: a randomized controlled phase 3 trial. Lancer Oncol 2014;14: 415-423
- Adjuvant chemotherapy for localised resectable soft tissue sarcoma of adults: Meta-analysis of individual data. Sarcoma Meta-analysis collaboration. Lancet 1997, 350:1647-1654, Pervaiz N, Colterjohn N, Farrkhyar F et al. A systematic meta-analysis of randomized controlled trial of adjuvant chemotherapy for adult soft tissue sarcoma. Cancer 2008; 113:573-581.
