RESUMO
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma with an infiltrative growth pattern that makes it challenging to clear margins. High quality data regarding DFSP natural history, management, and outcomes are limited. METHODS: Data were retrospectively collected for adult DFSP patients who underwent resection at 10 institutions in eight countries. Demographics, tumor characteristics, treatment strategies, and outcomes were analyzed. RESULTS: Analysis included 347 patients consisting of young (median, 42 years), White (76.2%), males (54.2%) with truncal lesions (57.3%). The majority (76.8%) were symptomatic at presentation. Preoperative imaging was used in 55.9% of cases. Diagnosis was established with excisional biopsy in 50.9% versus incisional biopsy in 25.0% of cases. Despite planned margins of >1.0 cm in 67.4% of cases, only 69.0% of patients achieved R0 resection. Twenty-two percent of patients underwent at least one re-excision. R0 resection was achieved at a second procedure in 80.2% and a third procedure in 86.2%. Ultimately, R0 resection was feasible in 89.5% of all patients. Fibrosarcomatous transformation (FST) was observed in 12.6%. In total, 6.6% (N = 23) recurred (17 local, six distant). Of the six distant recurrences, 50.0% had FST. With a median follow-up of 47.0 months, disease-specific survival rate was 98.8%. In multivariable analysis, R0 margins at index resection were associated with wider circumferential margins and non-FST histology. CONCLUSIONS: In this international, multicenter collaborative, DFSP practice patterns were heterogeneous but achieved favorable recurrence rates and survival. Multiple excisions to clear margins remain commonplace and can inform future efforts to optimize margin selection.
RESUMO
BACKGROUND: Following publication of the MSLT-II trial showing no survival benefit of completion lymphadenectomy (CLND) in patients with melanoma sentinel lymph node (SLN) metastases, it is expected that practice patterns have changed. The purpose of this study is to understand real-world practices and outcomes after publication of this landmark trial. PATIENTS AND METHODS: Patients with truncal/extremity melanoma SLN metastases diagnosed between 2013 and 2019 at four academic cancer centers were included in this retrospective cohort study. Descriptive statistics, Cox proportional hazards model, and multivariable regression were used to characterize the cohort and identify predictors of CLND, harboring non-SLN (NSLN) metastases, and survival. RESULTS: Results of 1176 patients undergoing SLN biopsy, 183 had SLN metastases. The number of patients who underwent CLND before versus after trial publication was 75.7.% versus 20.5% (HR 0.16, 95% CI 0.09-0.28). Of those undergoing nodal observation (NO), 92% had a first nodal-basin ultrasound, while 63% of patients had a fourth. In exploratory multivariable analyses, age ≥ 50 years was associated with lower rate of CLND (HR 0.58, 95% CI 0.36-0.92) and larger SLN deposit (> 1.0 mm) with increased rate of CLND (HR 1.87, 95% CI 1.17-3.00) in the complete cohort. Extracapsular extension was associated with increased risk of NSLN metastases (HR 12.43, 95% CI 2.48-62.31). Adjusted survival analysis demonstrated no difference in recurrence or mortality between patients treated with CLND versus NO at median 2.2-year follow-up. CONCLUSION: Nodal observation was rapidly adopted into practice in patients with melanoma SLN metastases at four centers in Canada. Younger age and higher nodal burden were associated with increased use of CLND after trial publication. Ultrasound (US) surveillance decreased with time from SLNB. In our study, CLND was not associated with a decreased risk of recurrence or mortality.
