Denis H. Y. Leung

OBJECTIVE: To analyze the outcome of 200 patients with gastrointestinal stromal tumor (GIST) who were treated at a single institution and followed up prospectively. SUMMARY BACKGROUND DATA: A GIST is a visceral sarcoma that arises from the gastrointestinal tract. Surgical resection is the mainstay of treatment because adjuvant therapy is unproven. METHODS: Two hundred patients with malignant GIST were admitted and treated at Memorial Hospital during the past 16 years. Patient, tumor, and treatment variables were analyzed to identify patterns of tumor recurrence and factors that predict survival. RESULTS: Of the 200 patients, 46% had primary disease without metastasis, 47% had metastasis, and 7% had isolated local recurrence. In patients with primary disease who underwent complete resection of gross disease (n = 80), the 5-year actuarial survival rate was 54%, and survival was predicted by tumor size but not microscopic margins of resection. Recurrence of disease after resection was predominantly intraabdominal and involved the original tumor site, peritoneum, and liver. CONCLUSIONS: GISTs are uncommon sarcomas. Tumor size predicts disease-specific survival in patients with primary disease who undergo complete gross resection. Tumor recurrence tends to be intraabdominal. Investigational protocols are indicated to reduce the rate of recurrence after resection and to improve the outcome for patients with GIST.

PURPOSE: To identify specific independent adverse clinicopathologic factors for event-free survival in a cohort of consecutively treated patients with extremity soft tissue sarcomas. PATIENTS AND METHODS: Prospectively collected data from a population of 1,041 adult patients with localized (American Joint Committee on Cancer [AJCC] stage IA to IIIB) extremity soft tissue sarcomas were analyzed. Patients were treated at a single institution between 1982 and 1994. Patient, tumor, and pathologic factors were analyzed by univariate and multivariate techniques to identify independent prognostic factors for the end points of local recurrence, distant recurrence, disease-specific survival, and post-metastasis survival. RESULTS: The 5-year survival rate for this cohort of patients was 76%, with a median follow-up time of 3.95 years. Significant independent adverse prognostic factors for local recurrence were age greater than 50 years, recurrent disease at presentation, microscopically positive surgical margins, and the histologic subtypes fibrosarcoma and malignant peripheral-nerve tumor. For distant recurrence, intermediate tumor size, high histologic grade, deep location, recurrent disease at presentation, leiomyosarcoma, and nonliposarcoma histology were independent adverse prognostic factors. For disease-specific survival, large tumor size, high grade, deep location, recurrent disease at presentation, the histologic subtypes leiomyosarcoma and malignant peripheral-nerve tumor, microscopically positive surgical margins, and lower extremity site were adverse factors. For post-metastasis survival, only large tumor size ( > 10 cm) was an adverse prognostic factor. CONCLUSION: The independent adverse prognostic factors for distant recurrence and disease specific survival differ from those identified for subsequent local recurrence. Patients with microscopically positive surgical margins or patients who present with locally recurrent disease are at increased risk for subsequent local recurrence and tumor-related mortality. Specific histopathologic subtypes are associated with increased risks for local failure and tumor-related mortality.

PURPOSE: This trial was performed to evaluate the impact of adjuvant brachytherapy on local and systemic recurrence rates in patients with soft tissue sarcoma. PATIENTS AND METHODS: In a single-institution prospective randomized trial, 164 patients were randomized intraoperatively to receive either adjuvant brachytherapy (BRT) or no further therapy (no BRT) after complete resection of soft tissue sarcomas of the extremity or superficial trunk. The adjuvant radiation was administered by iridium-192 implant, which delivered 42 to 45 Gy over 4 to 6 days. The two study groups had comparable distributions of patient and tumor factors, including age, sex, tumor site, tumor size, and histologic type and grade. RESULTS: With a median follow-up time of 76 months, the 5-year actuarial local control rates were 82% and 69% in the BRT and no BRT groups (P = .04), respectively. Patients with high-grade lesions had local control rates of 89% (BRT) and 66% (no BRT) (P = .0025). BRT had no impact on local control in patients with low-grade lesions (P = .49). The 5-year freedom-from-distant-recurrence rates were 83% and 76% in the BRT and no BRT groups (P = .60), respectively. Analysis by histologic grade did not demonstrate an impact of BRT on the development of distant metastasis, despite the improvement in local control noted in patients with high-grade lesions. The 5-year disease-specific survival rates for the BRT and no BRT groups were 84% and 81% (P = .65), respectively, with no impact of BRT regardless of tumor grade. CONCLUSION: Adjuvant brachytherapy improves local control after complete resection of soft tissue sarcomas. This improvement in local control is limited to patients with high-grade histopathology. The reduction in local recurrence in patients with high-grade lesions is not associated with a significant reduction in distant metastasis or improvement in disease-specific survival.

OBJECTIVE: To analyze treatment and survival of a large cohort of patients with retroperitoneal soft-tissue sarcomas (STS) treated and prospectively followed at a single institution. SUMMARY BACKGROUND DATA: Retroperitoneal STS are relatively uncommon and constitute a difficult management problem. Although surgical resection is often difficult or impossible, current chemotherapy is not effective and radiation is limited by toxicity to adjacent structures. Thus, complete surgical resection remains the most effective modality for selected primary and recurrent disease. METHODS: Five hundred patients with retroperitoneal STS were admitted and treated between July 1, 1982, and September 30, 1997, and prospectively followed. Patient, tumor, and treatment variables were analyzed for disease-specific and disease-free survival. Survival was determined with the Kaplan-Meier method. Statistical significance was evaluated using the logrank test for univariate influence and Cox model stepwise regression for multivariate influence. RESULTS: Two hundred seventy-eight patients (56%) had primary disease and 222 (44%) recurrent disease. Median follow-up was 28 months (range 1 to 172 months), 40 months for survivors. Median survival was 72 months for patients with primary disease, 28 months for those with local recurrence, and 10 months for those with metastasis. For patients with primary or locally recurrent tumors, unresectable disease, incomplete resection, and high-grade tumors significantly reduced survival time. CONCLUSIONS: In this study of patients with retroperitoneal STS, stage at presentation, high histologic grade, unresectable primary tumor, and positive gross margin are strongly associated with the tumor mortality rate. Patients approached with curative intent should undergo aggressive attempts at complete surgical resection. Incomplete resection should be undertaken only for symptom relief.

OBJECTIVE: To define the significance of positive microscopic resection margins in a large cohort treated for soft tissue sarcoma. METHODS: The authors analyzed 2,084 patients with localized primary soft tissue sarcoma (all anatomic sites) treated from 1982 to 2000. Clinicopathologic variables studied included tumor site, size, depth, histologic type, grade, and resection margin status. Treatment other than resection was not analyzed. Study endpoints included local and distant recurrence-free and disease-specific survival rates, estimated by the Kaplan-Meier method. Univariate and multivariate analyses were performed using the log-rank test and the Cox proportional hazards model. RESULTS: Median follow-up was 50 months. After primary resection, 1,624 (78%) patients had negative and 460 (22%) had positive resection margins. Having positive margins nearly doubled the risk of local recurrence and increased the risk of distant recurrence and disease-related death. Seventy-two percent of patients with positive margins had no recurrence. Resection margin did not predict local control for retroperitoneal sarcomas or fibrosarcomas. Resection margin remained significantly associated with distant recurrence-free survival and disease-specific survival across all subsets after adjusting for other prognostic variables. The overall 5-year disease-specific survival rates for negative and positive margins were 83% and 75%. CONCLUSIONS: Positive microscopic resection margins significantly decrease the local recurrence-free survival rate for other-than-primary fibrosarcoma and retroperitoneal sarcomas, and independently predict distant recurrence-free survival rates and disease-specific survival rates for all patient subsets. Adjuvant therapy should be considered in the management of soft tissue sarcoma to increase local control. Because 72% of positive margins did not equate with inevitable local recurrence, considerable clinical judgment is required in considering additional treatment. Microscopic resection margins should be considered for inclusion in staging systems and treatment algorithms that address local recurrence.