Dermatofibrosarcoma protuberans: A 10-year experience

Establishment and characterization of NCC-DFSP5-C1: a novel patient-derived dermatofibrosarcoma protuberans cell line

Dermatofibrosarcoma protuberans (DFSP) is the most prevalent dermal sarcoma, characterized by the presence of the fusion of the collagen type I alpha 1 (COL1A1) gene with the platelet-derived growth factor beta chain (PDGFB) gene. Although PDGF receptor inhibitor imatinib mesylate was approved for the treating patients with unresectable or metastatic DFSP, disease progression was shown in 9.2% of the patients. Therefore, developing novel therapeutic strategies is crucial for improving the prognosis of DFSP. Patient-derived cell lines play a vital role in preclinical studies; however, only a limited number of DFSP cell lines are currently available in public cell banks. Here, we successfully established a novel DFSP cell line (NCC-DFSP5-C1) using surgically resected tumor tissue from a patient with DFSP. NCC-DFSP5-C1 cells were confirmed to carry the COL1A1-PDGFB translocation and maintain the same mutation as the original tumor tissue. They exhibited consistent growth, formed spheroids, and were invasive. By screening a drug library using NCC-DFSP5-C1 and four previously established DFSP cell lines, we identified anti-cancer drugs that inhibit DFSP cell proliferation. Our observations suggest that the NCC-DFSP5-C1 cell line holds promise as a valuable tool for conducting fundamental and preclinical studies for DFSP.

Dermatofibrosarcoma Protuberans Recurrence After Wide Local Excision Versus Mohs Micrographic Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Local recurrence (LR) rates of dermatofibrosarcoma protuberans (DFSP) treated with different surgical modalities are unknown.

OBJECTIVE

To evaluate the differences in LR rates of DFSP treated with wide local excision (WLE) versus Mohs micrographic surgery (MMS).

MATERIALS AND METHODS

Pertinent studies of DFSP treated with either WLE or MMS were identified through a search of multiple databases, including Ovid MEDLINE (1946-2018), Embase (1988-2018), Web of Science (1975-2018), and Scopus (1970-2018). Comparative 2-arm and noncomparative single-arm studies were assessed through meta-analyses.

RESULTS

Of the 517 studies identified, 88 met inclusion criteria (12 comparative studies; 76 single-arm studies). In the 12 comparative studies, 352 patients with DFSP underwent MMS and 777 patients with DFSP underwent WLE. The LR rate was 1.7% after MMS and 3.7% after WLE (odds ratio, 1.549; 95% CI, 0.710-3.381; p = .27). In the 76 noncomparative studies, 980 patients underwent MMS (LR rate, 1.5%; 95% CI, 0.9%-2.1%; p < .001), and 2,215 patients underwent WLE (LR rate, 9.4%; 95% CI, 7.5%-11.3%; p < .001).

CONCLUSION

The LR rate of DFSP in patients treated with MMS is lower than in patients treated with WLE. Because of high rates of postoperative DFSP LR, MMS should be strongly considered when available.

A case of dermatofibrosarcoma protuberans and reflectance confocal microscopy of a post-surgical skin graft

Dermatofibrosarcoma protuberans (DFSP) is an overall rare malignancy yet is one of the most common cutaneous sarcomas. The diagnosis of DFSP is typically made following histopathologic examination of the lesion, classically revealing a storiform pattern of spindle cells with elongated nuclei infiltrating the dermis and subcutis. Surgical excision is the standard treatment. Local recurrence is estimated to occur in 20-50% of cases, thus frequent postsurgical monitoring is required. Noninvasive imaging modalities offer a potential alternative to multiple repeat biopsies. We report the first case where reflectance confocal microscopy accompanied clinical examination in monitoring for DFSP recurrence postsurgical excision.

Role of postoperative radiotherapy in dermatofibrosarcoma protuberans: a propensity score-matched analysis

Objective

This study aimed to evaluate the role of postoperative radiotherapy (RT) in dermatofibrosarcoma protuberans (DFSP) and identify the prognostic factors influencing the disease-free survival (DFS).

Methods

A total of 184 patients with DFSP were analyzed from 2000 to 2016. The regression model was used to examine the prognostic factors for DFS. Baseline covariates were balanced using a propensity score model. The role of RT was assessed by comparing the DFS of the surgery + RT group with that of the surgery group.

Results

The median follow-up was 58 months (range, 6–203 months). The 5-year DFS rate was 89.8%. The univariate analysis showed that age ≥ 50 years, presence of fibrosarcoma, margins < 2 cm, and tumor size ≥5 cm were associated with worse DFS (P = 0.002, P <  0.001, P = 0.030, and P = 0.032, respectively). The multivariate Cox regression model revealed that age, margin width, lesion number, and histological subtype independently affected DFS. The Ki-67 expression was related to age and histological subtype. Patients with Ki-67 ≥ 17% showed a worse DFS than those with Ki-67 < 17% (35.8% vs 87.8%, P = 0.002). In the matched cohort, DFS was significantly higher in the S + RT group than in the S group (5-year DFS, 88.1% vs 56.2%, P = 0.044).

Conclusions

Age, margin width, lesion number, and histological subtype were independent risk factors for DFS in patients with DFSP. The high expression of Ki-67 could predict a poor prognosis. Postoperative RT could improve DFS for patients with DFSP.