From the Guidelines
Treatment for soft tissue alveolar sarcoma of the thigh should involve a multimodal approach centered on surgical resection with wide margins, followed by radiation therapy and consideration of systemic treatment, as recommended by the most recent guidelines 1.
Key Considerations
- Surgery should be performed by a surgeon specifically trained in the treatment of soft tissue sarcomas, with the goal of completely removing the tumor while preserving limb function whenever possible.
- Radiation therapy, typically 50-60 Gy over 5-6 weeks, is often administered either pre-operatively to shrink the tumor or post-operatively to eliminate microscopic disease, especially for high-grade, deep tumors with a diameter of >5 cm 1.
- Chemotherapy regimens may be considered, but adjuvant chemotherapy is not a standard treatment and is not recommended in chemotherapy non-responsive histologic subtypes, such as alveolar soft part sarcoma 1.
Treatment Approach
- The standard surgical procedure is a wide excision (en bloc resection) with negative margins (R0) and limb salvage procedure whenever feasible 1.
- Re-excision by an expert team should be discussed in a multidisciplinary team (MDT) if surgery was performed outside a reference centre or if margins are not satisfactory 1.
- Radiation therapy should be considered for cases with at least one of the following risk factors: high-grade (G2-3), deep, >5 cm lesions, and may be avoided for G1, R0, <5cm, superficial tumours of the limbs and trunk wall 1.
Systemic Treatment
- Chemotherapy regimens, such as doxorubicin and ifosfamide, may be considered for advanced or metastatic disease, but response rates vary and alveolar soft part sarcoma tends to be chemoresistant 1.
- Targeted therapies, like pazopanib, or immune checkpoint inhibitors, like pembrolizumab, may be considered for advanced or metastatic disease 1.
Multidisciplinary Care
- Treatment should be coordinated by a multidisciplinary sarcoma team, as this rare and aggressive subtype has a propensity for late metastases, particularly to the lungs and brain, necessitating long-term surveillance with regular imaging studies for at least 5-10 years after initial treatment 1.
From the FDA Drug Label
The efficacy of pazopanib was evaluated in VEG110727, a randomized, double-blind, placebo-controlled, multicenter trial ( NCT00753688). Patients with metastatic STS who had received prior chemotherapy, including anthracycline treatment, or were unsuited for such therapy, were randomized (2:1) to receive pazopanib 800 mg once daily or placebo Efficacy results are presented in Table 9 and Figure 2. Table 9 Efficacy Results in STS Patients by Independent Assessment in VEG110727 HR Endpoint/Trial populationPazopanibPlacebo(95% CI) PFS Overall ITTN = 246N = 1230.35 a Median (months)4.61.6(0.26,0.48)
The treatment for soft tissue alveolar sarcoma of the thigh with pazopanib is based on a study where patients with metastatic STS received pazopanib 800 mg once daily. The results showed a median PFS of 4.6 months for patients receiving pazopanib compared to 1.6 months for those receiving placebo 2.
- Key points:
- Pazopanib was evaluated in a randomized, double-blind, placebo-controlled trial for metastatic STS.
- Patients received pazopanib 800 mg once daily or placebo.
- The median PFS was 4.6 months for pazopanib and 1.6 months for placebo.
From the Research
Treatment Options for Soft Tissue Alveolar Sarcoma of the Thigh
- The primary treatment for alveolar soft part sarcoma (ASPS) is wide resection of the tumor, as stated in 3, 4, 5
- Adjuvant radiotherapy may be added to prevent local recurrence, especially when the surgical margin is questionable, as mentioned in 3
- Chemotherapy may be used in some cases, but its effectiveness is still being studied, with some studies showing no significant benefit 4, 6
- Targeted therapy, such as pazopanib, has shown promise in improving survival rates for patients with metastatic ASPS, as reported in 7
Prognostic Factors
- The presence of metastases at presentation is a significant adverse prognostic factor for disease-specific survival, as stated in 7
- Tumor size and depth are also important prognostic factors, with larger and deeper tumors being associated with a higher risk of metastases, as mentioned in 7
- Age and tumor location may also play a role in prognosis, with younger patients and those with tumors in certain locations tend to have better outcomes, as reported in 6