Hypothesis: Abdominal wall tumors, though clinically similar, have varying degrees of biological behavior.
Design: Retrospective review of prospective databases.
Setting: Memorial Sloan-Kettering Cancer Center.
Patients: Eighty-five patients with abdominal wall soft tissue tumors.
Main outcome measures: Primary endpoints included time to first local recurrence, distant metastases, and disease-related mortality. Survival analysis was performed by Kaplan-Meier method, and comparisons were made by log-rank analysis.
Results: Thirty-nine desmoids, 32 soft tissue sarcomas (STS), and 14 dermatofibrosarcoma protuberans (DFSP) underwent surgery directed at achieving margin-negative resection. Unlike DFSP, most STS (77%) and desmoids(87%) were deep lesions requiring full-thickness abdominal wall resection and mesh reconstruction. Median follow-up time was 53 months, 101 months, and 31 months, with 5-year local recurrence-free survival rates of 97%, 100%, and 75%, for desmoids, DFSP, and STS, respectively. Desmoid tumors resected with positive microscopic margins had higher local failure rates (68% [positive margin] vs 100% [negative margin] 5-yr local recurrence-free survival, P<.05). For STS, high grade, deep location, and size at or above 5 cm were adverse prognostic factors for disease-specific and distant recurrence-free survival (P<.05); patients experiencing local recurrence was associated with decreased 5-year relapse-free survival rates (87% [primary] vs 50% [local recurrence], P<.05). Characteristically, no DFSP or desmoid developed distant metastases. Soft tissue sarcomas had significantly lower relapse-free survival rates than DFSP or desmoids (P<.05).
Conclusion: Abdominal wall tumors demonstrate a broad spectrum of biological behavior. Desmoids and DFSP are a local problem. High grade, size at or above 5 cm, and deep location predict distant failure and tumor-related mortality for patients with STS. Complete surgical resection is the recommended treatment approach to achieve local control. Stratification by prognostic factors will facilitate selection of patients with STS for adjuvant systemic therapies.