Treatment of Low-Grade Myxoid Spindle Cell Sarcoma in the Lung
Surgical resection with clear margins is the definitive treatment for this elderly patient with a 7 cm low-grade myxoid spindle cell sarcoma in the lung, ideally performed via video-assisted thoracoscopic surgery (VATS) if technically feasible, at a high-volume center with expertise in both thoracic surgery and sarcoma management.
Primary Treatment Approach
Surgical Resection as Standard of Care
Complete surgical excision with negative margins remains the cornerstone of treatment for low-grade fibromyxoid sarcoma (LGFMS), which appears to be the most likely diagnosis given the description of "low-grade myxoid spindle cell sarcoma" 1, 2.
Lobectomy is generally preferred for lung lesions of this size, though limited resections (wedge resection) may be justified in elderly patients with adequate functional margins 3.
VATS approach should be strongly considered as it demonstrates significantly lower complication rates (28% vs 45%) and shorter hospital stays in elderly patients aged ≥70 years, with no perioperative deaths compared to 3.6% mortality with open thoracotomy 3.
Surgical Considerations Specific to Elderly Patients
Age alone should not preclude surgical treatment—modern minimally invasive techniques achieve operative mortality rates of only 0.8% in elderly patients (mean age 72 years) compared to historical rates of 7.1% 3.
Referral to a high-volume center is critical, as lung cancer-specific mortality is reduced with an adjusted OR of 0.86 for each 10% increase in surgery rates at experienced institutions 3.
Pneumonectomy should be avoided in elderly patients due to higher perioperative morbidity and mortality 3.
Alternative Treatment if Surgery is Not Feasible
Stereotactic Ablative Body Radiation Therapy (SABR)
If the patient is medically inoperable due to comorbidities or poor functional status, SABR represents the best alternative with local control rates of approximately 90% 3.
SABR demonstrates lower 30-day mortality (1.7%) compared to surgery (8.3%) in elderly patients ≥75 years, though long-term disease-specific survival favors surgery after 6 months 3.
SABR is delivered over 3-8 fractions, making it particularly attractive for elderly patients 3.
Important Caveat About SABR for This Tumor
- SABR evidence is primarily derived from NSCLC studies, not soft tissue sarcomas 3. Low-grade fibromyxoid sarcomas are generally considered radiotherapy-insensitive 4, making surgical resection even more critical for this histology.
Adjuvant and Systemic Therapy Considerations
Limited Role of Chemotherapy and Radiation
LGFMS is characteristically insensitive to both chemotherapy and radiotherapy 4, 1, making complete surgical excision with clear margins the only curative option.
Adjuvant therapy warrants consideration only in the context of aggressive sarcoma behavior, particularly for tumors ≥7 cm which demonstrate significantly worse survival (7.5% vs 56% for <7 cm tumors) 5.
Molecular Characterization
Pathologic confirmation with MUC4 immunohistochemistry should be performed, as this marker shows consistent positivity in LGFMS and helps distinguish it from other spindle cell lesions 1, 6.
Genetic testing for FUS-CREB3L2 fusion (from t(7;16) translocation) can confirm the diagnosis, as this is present in the majority of LGFMS cases 1.
Critical Prognostic Factors and Follow-Up
High-Risk Features Requiring Aggressive Management
Tumor size ≥7 cm is a significant negative prognostic factor, with 5-year survival of only 7.5% for large tumors versus 56% for smaller ones in spindle cell lung carcinomas 5.
LGFMS has high recurrence rates and potential for late metastatic spread (occurring in 58% of cases in one series), with metastases developing years to decades after initial resection 2.
Disease-free interval <6 months predicts poor outcomes (0% survival vs 33% for ≥6 months) in aggressive spindle cell tumors 5.
Long-Term Surveillance Strategy
Extensive long-term follow-up is mandatory given the indolent nature of LGFMS, with documented recurrences and metastases occurring up to 30-50 years after initial diagnosis 4, 2.
Serial chest CT imaging should be performed to detect pulmonary metastases, the most common site of distant spread 1, 2.
Multidisciplinary Team Composition
The patient should be evaluated by a multi-specialty team including:
- Thoracic surgeon experienced in minimally invasive techniques at a high-volume center 3
- Sarcoma pathologist for accurate histologic diagnosis and margin assessment 1
- Radiation oncologist for SABR evaluation if surgery is contraindicated 3
- Geriatric specialist to assess functional status and comorbidities 3
Common Pitfalls to Avoid
Misdiagnosis is common due to the deceptively benign histologic appearance of LGFMS, which has been repeatedly misdiagnosed as neurofibroma in documented cases 4, 1.
Inadequate surgical margins lead to high recurrence rates—meticulous attention to achieving clear margins is essential 4, 1, 2.
Underestimating the aggressive potential of "low-grade" sarcomas—despite bland histology, these tumors demonstrate significant metastatic potential requiring aggressive local control 5, 2.
Denying surgery based solely on chronological age rather than functional status and comorbidities represents inappropriate age discrimination 3.