Dermatofibrosarcoma Protuberans: A Study of 148 Patients.

INTRODUCTION: Dermatofibrosarcoma protuberans (DFSP) is the most common sarcoma of the skin. Although distant metastases are infrequent, DFSP is highly aggressive locally with frequent local recurrences. It has been reported that the presence within the tumour of areas histopathologically mimicking fibrosarcoma may increase the risk of recurrence. OBJECTIVE: The objective of this study was to review the clinical features of our patients with DFSP and the factors associated with recurrence of the tumour, focussing on the presence of fibrosarcomatous areas. METHODS: Retrospective study of patients with DFSP diagnosed in 1990-2021 in a tertiary university hospital. The medical records were reviewed to obtain the following data: age, sex, tumour location, diameter, evolution time, presence of fibrosarcomatous areas, development of recurrence, and follow-up. Factors possibly associated with disease-free survival were analysed with Kaplan-Meier method and multivariate Cox regression. RESULTS: 148 patients (74 women/74 men, mean age 46.28 years, SD 14.431) were included in the study. Tumours involved the head and neck in 15 cases, thorax in 31, abdomen in 16, upper back in 43, lower back in 10, upper extremities in 10, and lower extremities in 23. Fibrosarcoma-like areas were observed in 16 tumours (10.81%). In 17 patients (11.49%), recurrences were observed (13 local recurrences, 3 lung metastasis, and 1 local recurrence with lung metastasis). Fibrosarcomatous DFSP recurred more frequently than classic DFSP (50% vs. 6.82%, respectively), and its disease-free survival was significantly lower (p < 0.001). In multivariate Cox regression, the presence of fibrosarcomatous areas was the only factor influencing disease-free survival. CONCLUSIONS: It is important to identify the fibrosarcomatous variant since it recurs more frequently and has lower recurrence-free survival. Distant metastases, mainly in the lung, are also more frequent in fibrosarcomatous DFSP.

Dermatofibrosarcoma Protuberans: A Clinicopathologic and Therapeutic Analysis of 254 Cases at a Single Institution.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade tumor that typically does not metastasize but often recurs. Fibrosarcomatous DFSP (FS-DFSP) is associated with a substantially higher rate of metastasis and a poorer prognosis. OBJECTIVE: This study sought to investigate the epidemiological, histopathological, and clinical characteristics of DFSP, especially with a particular focus on FS-DFSP. MATERIALS AND METHODS: Clinical data from 254 patients treated between January 1999 and July 2018 were retrospectively reviewed. Endpoints of the study were the incidence of significant disease-related clinical events. RESULTS: Follow-up data from 211 patients were available for analysis, with a median follow-up time of 38 months (range: 1-196 months). The 5-year recurrence-free survival rate of patients underwent wide-local excision (WLE) was 97.1%. Patients underwent WLE exhibited a significantly decreased recurrence rate relative to patients treated through local excision (2.9% vs 37.7%; p < .001). Fibrosarcomatous DFSP had significantly higher rates of distant metastasis (66.7% [n = 4] vs 2.0% [n = 4]; p < .001) and long-term mortality (50.0% [n = 3] vs 1.5% [n = 3]; p < .001), compared with classical DFSP (C-DFSP). CONCLUSION: Wide-local excision is an effective means of reducing DFSP recurrence. Rates of metastasis are higher for FS-DFSP than for C-DFSP, with the former having significantly poorer outcomes.

Vulvar sarcoma outcomes by histologic subtype: a Surveillance, Epidemiology, and End Results (SEER) database review.

OBJECTIVE: Vulvar cancers account for 5% of all gynecologic malignancies; only 1%-3% of those vulvar cancers are primary vulvar sarcomas. Given the rarity of vulvar sarcomas, outcome data specific to histopathologic subtypes are sparse. The aim of this study was to identify clinical and pathologic factors of primary vulvar sarcomas that are associated with survival and may inform treatment decisions. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was searched for women diagnosed with vulvar sarcoma between 1973 and 2018. We identified 315 patients and reviewed their demographic, clinicopathologic, surgical, and survival information. Statistical analyses included χ2 and t-tests, Kaplan-Meier survival, and Cox regression analyses. RESULTS: The most common histopathologies of vulvar sarcomas were dermatofibrosarcomas (85/315, 27%) and leiomyosarcomas (72/315, 22.9%). Rhabdomyosarcomas (18/315, 5.7%), liposarcomas (16/315, 5.1%), and malignant fibrous histiocytomas (16/315, 5.1%) were less frequent. The majority of patients underwent surgery (292/315, 92.7%), which included lymph node dissections in 21.6% (63/292). Survival and lymph node involvement varied significantly with histologic subtype. The 5-year disease-specific survival for dermatofibrosarcomas, liposarcomas, and fibrosarcomas was 100% and only 60.3% and 62.5% for malignant fibrous histiocytomas and rhabdomyosarcomas, respectively. None of the patients with (dermato)fibrosarcomas, liposarcomas, or leiomyosarcomas had positive lymph nodes, in contrast to rhabdomyosarcomas and malignant fibrous histiocytomas with 77.8% and 40% positive lymph nodes, respectively. The 5-year disease-specific survival for women with positive lymph nodes was 0%. CONCLUSIONS: Vulvar sarcomas are heterogeneous with survival highly dependent on the histopathologic subtype. While surgical excision is the mainstay of treatment for all vulvar sarcomas, staging lymphadenectomy should be deferred for (dermato)fibrosarcomas, liposarcomas, and leiomyosarcomas as there were no cases of lymph nodes metastases.

Survival in patients with primary dermatofibrosarcoma protuberans: National Cancer Database analysis.

BACKGROUND: The predictors of mortality, second surgery, and postoperative radiation therapy for treating dermatofibrosarcoma protuberans (DFSP) are not well described. OBJECTIVE: We sought to determine the impact of patient demographics, tumor characteristics, and treatment site and modality on survival after primary DFSP. METHODS: A retrospective analysis of data from the National Cancer Database was performed for patients diagnosed with DFSP during 2003-2012. RESULTS: A total of 5249 cases were identified. Of these, 3.1% of patients died during an average of 51.4 months of follow-up. After adjusting for relevant factors, lack of insurance, Medicaid and Medicare insurance, anaplastic histology, and positive postoperative margins all predicted mortality, while treatment at an Integrated Network Cancer Program predicted survival (P < .05). Higher odds of postoperative radiation therapy were directly associated with large tumor size, anaplastic and poorly differentiated histology, and positive postoperative margins and inversely associated with treatment at high volume facilities, and non-head and neck tumors. Higher second surgery rates were associated with Hispanic ethnicity, and lower rates were associated with female sex. LIMITATIONS: Survival data was not cancer-specific. CONCLUSION: Better understanding of factors affecting survival outcomes might help improve management of DFSP and delineate other potential causes of increased morbidity and mortality.

Dermatofibrosarcoma protuberans: A retrospective study of clinicopathologic features and related Akt/mTOR, STAT3, ERK, cyclin D1, and PD-L1 expression.

BACKGROUND: Little is known regarding oncoproteins other than platelet-derived growth factor subunit B in dermatofibrosarcoma protuberans (DFSP). Moreover, the risk factors for worse prognosis are controversial. OBJECTIVE: We sought to determine the clinicopathologic features and key factors for adverse outcome in DFSP, including the implication of expression of protein kinase B (Akt)/mammalian target of rapamycin (mTOR), signal transducer and activator of transcription 3 (STAT3), extracellular signal regulated kinase (ERK), cyclin D1, and programmed death ligand 1 (PD-L1). METHODS: Clinicopathologic and immunohistochemical analyses were performed for 44 DFSPs having wide local excision and 92 dermatofibromas as controls. RESULTS: Compared with the 35 nonrecurrent DFSPs, the 9 recurrent DFSPs exhibited larger tumor size, deeper invasion beyond the subcutis, and more diverse histologic subtype. The fibrosarcomatous subtype revealed frequent mitotic figures and a high cyclin D1-positive index. The 2 metastatic DFSPs (1 each of the fibrosarcomatous and myxoid subtypes) demonstrated 4 and 11 instances of local recurrence, respectively, as well as larger tumor size, deeper invasion beyond the subcutis, and high expression of cyclin D1. Expression of Akt/mTOR, STAT3, ERK, and PD-L1 ranged from none or low in the primary skin lesions to high in the corresponding metastatic sites. Akt/mTOR and ERK were expressed more frequently in DFSP than in dermatofibroma. LIMITATIONS: Lack of information on patients before hospital evaluation. CONCLUSION: Complex factors beyond fibrosarcomatous subtype may portend local recurrence or metastasis. Akt/mTOR, STAT3, ERK, and PD-L1 may be associated with development and/or progression of DFSP.

Effect of Non-Hodgkin Lymphoma on Survival in Patients With Malignant Fibrous Histiocytoma, Kaposi Sarcoma, and Sebaceous Carcinoma: A SEER Population-Based Study.

OBJECTIVE: To quantify the behavior of dermatofibrosarcoma protuberans (DFSP), malignant fibrous histiocytoma (MFH), Kaposi sarcoma (KS), and sebaceous carcinoma (SC) in patients with a history of non-Hodgkin lymphoma (NHL). PATIENTS AND METHODS: Subjects with a diagnosis of DFSP, MFH, KS, or SC between 1990 and 2006 were identified in the Surveillance, Epidemiology, and End Results Program database. For each skin cancer type, the standardized mortality ratio (SMR) for death due to any cause and death due to skin cancer was estimated. RESULTS: From 1990 through 2006, 25,357 skin cancers were identified: 4,192 DFSP, 6,412 MFH, 10,543 KS, and 4,222 SC. For patients with a history of non-CLL NHL, SMRs for death due to any cause were 1.45 (95% confidence interval [CI], 1.03-2.04; p = 0.04) for MFH, 2.90 (95% CI, 2.50-3.36; p < 0.001) for KS, and 3.25 (95% CI, 1.84-5.75; p < 0.001) for SC and SMRs for death due to skin cancer were 0.55 (95% CI, 0.23-1.31; p = 0.18) for MFH, 2.93 (95% CI, 2.49-3.43; p < 0.001) for KS, and 4.07 (95% CI, 1.28-12.94; p < 0.001) for SC. CONCLUSION: Among patients with KS and SC, patients with a history of non-CLL NHL have a greater risk of overall and cause-specific death than expected.

Incidence and Survival of Primary Dermatofibrosarcoma Protuberans in the United States.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous sarcoma for which data on risk factors, incidence, and survival are limited. OBJECTIVE: The authors sought to establish a comprehensive report on the incidence of and survival from primary DFSP. METHODS: The authors used data from the 18 registries of the Surveillance, Epidemiology, and End Results Program from 2000 to 2010. RESULTS: Overall incidence was 4.1 per million person-years and steady over the decade. Trunk was the most common anatomic site except in older men. Incidence among women was 1.14 times higher than men (95% confidence interval [CI] of rate ratio: 1.07-1.22). Incidence among blacks was almost 2 times the rate among whites (95% CI of rate ratio: 1.8-2.1). Ten-year relative survival of DFSP was 99.1% (95% CI: 97.6-99.7). Increased age, male sex, black race, and anatomic location of the limbs and head as compared with the trunk were associated with higher all-cause mortality. CONCLUSION: This is the largest population-based study of DFSP derived from a cohort of almost 7,000 patients. The epidemiologic profile of DFSP differs from most skin cancers. Incidence is stable and highest among women and blacks. Worse survival is associated with increased age, male sex, black race, and anatomic location of the limbs and head.

A systematic review of outcome data for dermatofibrosarcoma protuberans with and without fibrosarcomatous change.

BACKGROUND: To our knowledge, no systematic review of dermatofibrosarcoma protuberans (DFSP) outcomes based on the presence or absence of fibrosarcomatous (FS) change has been performed. OBJECTIVE: We sought to compare available outcome data for DFSP versus DFSP-FS. METHODS: The literature was searched for DFSP and DFSP-FS reports with outcome data (local recurrence, metastasis, or death from disease). Chi-square tests were calculated to determine whether DFSP and DFSP-FS significantly differed in risk of local recurrence, metastasis, and death from disease. RESULTS: In all, 24 reports containing 1422 patients with DFSP and 225 with DFSP-FS are summarized. Risk of local recurrence, metastasis, and death from disease in DFSP-FS was significantly higher as compared with DFSP (local recurrence 29.8% vs 13.7%, risk ratio 2.2 [95% confidence interval 1.7-2.9]; metastasis 14.4% vs 1.1%, risk ratio 5.5 [95% confidence interval 4.3-7.0]; and death from disease 14.7% vs 0.8%, risk ratio 6.2 [95% confidence interval 5.0-7.8]). There was no significant difference in DFSP-FS outcomes based on proportion of FS change within tumors. LIMITATIONS: This study is based on previously reported data from different hospitals with no uniform process for reporting FS change. The impact of confounders (age, immune status, tumor location, treatment) could not be evaluated because of limited data. CONCLUSION: Based on available retrospective data, risk of metastasis and death is elevated in DFSP-FS as compared with DFSP. Even a low degree of FS involvement portends worse outcomes.

Cryotherapy for local recurrent dermatofibrosarcoma protuberans: experience in 19 patients.

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive, cutaneous, malignant tumor characterized by a high propensity for local relapse. Wide and deep local excision with reconstructive surgery is the current standard therapy for DFSP, with a local recurrence rate (LRR) of nearly 40%. In this study, we cured 19 patients with local recurrence of DFSP with 39 sessions of percutaneous cryoablation performed between July 2004 and August 2008. The LRRs after one, two and three cryosurgery sessions per patient were 68%, 54% and 0%, respectively. Moreover, the LRR did not differ with tumor location or size. Furthermore, all patients had a progression-free survival of >5 years. Only minor complications such as fever, local edema, mild nerve injury and local pain occurred, and were resolved within 1 week with symptomatic treatment. In our experience, percutaneous cryoablation is a relatively safe and efficient technique for the treatment of local recurrence of DFSPs.

Risk of subsequent primary malignancies after dermatofibrosarcoma protuberans diagnosis: a national study.

BACKGROUND: Patients frequently live many years after diagnosis of dermatofibrosarcoma protuberans (DFSP). OBJECTIVE: We sought to determine the risk of subsequent primary malignancy (SPM) after DFSP diagnosis. METHODS: Using the Surveillance, Epidemiology, and End Results database (1973-2008) for 3734 patients with DFSP, we compared the risk of developing 14 SPMs (12 most prevalent cancers in the United States plus other nonepithelial and soft tissue) relative to risk in the general population of same sex, race, and age and year of diagnosis. RESULTS: Patients given the diagnosis of DFSP had an overall increased risk of SPM (observed:expected [O:E], 1.20; 95% confidence intervals [CI], 1.04-1.39), with much of the overall increased risk attributable to increased risk of nonepithelial skin cancer (O:E, 9.94; 95% CI, 3.38-22.30). Specifically, female patients with DFSP were at increased risk of other nonepithelial skin cancer (O:E, 14.50; 95% CI, 3.46-38.98), melanoma (O:E, 2.59; 95% CI, 1.02-5.35), and breast cancer (O:E, 1.44; 95% CI, 1.00-2.00). Male patients were not at increased overall risk (O:E, 1.18; 95% CI, 0.96-1.44) of SPM or at increased risk of any specific malignancy (P > .05) adjusted for multiplicity of t tests. LIMITATIONS: Surveillance bias may have led to increased rates and earlier detection of primary malignances in patients with DFSP compared with the general population. Individual data that may reveal shared environmental causes of DFSP and SPM were unavailable. CONCLUSIONS: Patients with DFSP are at increased risk of a number of SPMs.

Evaluation of the role of radiotherapy in the management of dermatofibrosarcoma protuberans.

PURPOSE: The aim of this study was to evaluate the role of radiotherapy (RT) in the management of dermatofibrosarcoma protuberans (DFSP). METHODS: Twenty-eight patients treated with RT for DFSP between 1974 and 2012 at Gulhane Military Medical Academy (GMMA) Radiation Oncology Department were retrospectively evaluated. Twenty-five out of 28 patients (89%) received postoperative RT and 3 received definitive RT alone. In the 25 patients receiving postoperative RT, the type of surgical excision was limited excision in 5 patients and wide excision in the remaining 20. Median RT dose was 63.21±3.7 Gy (range 50-70). RESULTS: At a median follow-up of 5 years, 5-year overall survival (OS) for the whole patient group was 93%. No relationship was determined between the total delivered RT dose and OS. The 5-year OS of the 10 female patients was 90% whereas it was 94% for the 18 male patients (p>0.05). Five-year disease-free survival (DFS) for the patients undergoing wide excision with RT vs. those undergoing limited excision with RT was significantly superior (p <0.05) in patients treated with wide excision and RT. CONCLUSION: RT is an effective treatment option for DFSP patients with positive postoperative margins, recurrent disease and selected inoperable cases.

Dermatofibrosarcoma protuberans: clinical diagnoses and treatment results of 260 cases in China.

BACKGROUND AND OBJECTIVES: Dermatofibrosarcoma protuberans (DFSP) is a low-grade malignant tumor but has high local recurrence rate. The objectives of this study were to analyze their clinicopathologic factors and review the experience of multidisciplinary treatments. METHODS: A total of 260 patients who were treated between 1985 and 2006 in Fudan University Shanghai Cancer Center were evaluated. Outcomes were compared focusing on recurrence and survival. Classical DFSP and transformed DFSP were the two subtypes. RESULTS: After local excision, 50.2% of the patients were found to have residual tumors. The recurrence rate after local excision was significantly higher than that after wide excision (45.0% vs. 8.5%, P < 0.0001). Patients undergoing wide excision with margins ≥3 cm were found to have lower recurrence rate compared with those margins 1.5-2.5 cm (5.7% vs. 13.6%, P = 0.043). Compared with classical DFSPs, transformed DFSPs had significantly higher recurrence rate (34.5% vs. 6.3%, P < 0.0001), higher metastatic rate (23.5% vs. 0.4%, P < 0.0001), and worse prognosis (10-year survival rate 66.0% vs. 98.6%, P < 0.0001). CONCLUSIONS: Performing adequate initial resection is important for patients with DFSP. Once DFSP was diagnosed, wide excision with a best margin of ≥3 cm is necessary. Transformed DFSPs are more aggressive tumors which need more energetic treatments.

Dermatofibrosarcoma protuberans treated with wide local excision and followed at a cancer hospital: prognostic significance of clinicopathologic variables.

Dermatofibrosarcoma protuberans (DFSP) is a relatively rare low-grade sarcoma. Local control can usually be achieved by wide local excision, but some patients still develop recurrences. The aim of this study was to investigate the correlation between clinicopathologic factors and recurrence-free survival (RFS)/overall survival (OS) in a large series of DFSP patients from a single institution. The study group included sections and medical records of 122 patients (63 women and 59 men, median age of 43) with primary DFSP from UT-MD Anderson Cancer Center between 1976 and 2005. Fibrosarcomatous change was detected in 24 (20.9%) patients. Thirty-eight of 120 patients (31.7%) recurred with a median RFS of 10.2 years. The 5-year RFS rate was 64.2%. Based on univariate analyses, fibrosarcomatous change, mitotic count, metastasis at time of diagnosis, and acral location were significantly associated with shorter RFS. On multivariate analysis, acral location and fibrosarcomatous change remained significant for shorter RFS. Five-year OS was 95.5% (95% confidence interval: 75.42%-99.3%). On univariate analysis, mitotic count per square millimeter, presence of necrosis, and metastasis at time of diagnosis were significantly associated with lower OS. On multivariate analysis, only presence of metastasis remained significantly associated with shorter OS. DFSP-FS variant and acral site are associated with shorter recurrence-free interval after wide local excision. Therefore, patients with tumors on acral sites or those with a fibrosarcomatous component may benefit from aggressive therapies other than wide local excision. The only factor that remains significantly associated with decreased OS is detection of metastasis.

Clinicopathological assessment of T1 soft tissue sarcomas.

INTRODUCTION: Many studies have identified factors prognostic for soft tissue sarcomas of local recurrence, and distant metastasis. Several studies demonstrated that some subsets of patients could be safely treated by surgery alone, with acceptable rates of local recurrence. The aim of this study was to better clarify the necessity for adjuvant therapy and the width of the resected margin, by investigating the clinicopathological results of T1 (≤5 cm) soft tissue sarcomas. PATIENTS AND METHODS: A retrospective review was conducted in 96 adult patients treated for nonmetastatic AJCC T1 primary non-small round cell soft tissue sarcomas in our institution from 1995 to 2008. There were 49 men and 47 women ranging in age from 18 to 85 years (mean 51), and the observation period was 6-159 months (mean 52). The site of origin was the upper extremity in 21 cases, the lower extremity in 45, and the trunk in 30. Forty-four cases had high-grade malignant tumors, and 52 had low-grade malignant ones. Tumor size ranged from 0.7 to 5.0 cm (median size, 3.5 cm). Thirty-nine cases (41%) had previously undergone unplanned excision elsewhere. RESULTS: Eighty-nine (93%) of the patients were continuously free of disease, four were alive and currently free of disease, one was alive with metastasis, and two had died. The event-free survival rate at 5 years was 93.3%. The overall survival rate at 5 years was 94.1%. In 23 of the 45 cases with unplanned excisions (51%) residual tumor was found on histological examination. After definitive surgery, 92 patients (96%) had R0 margins. Four patients (4%) had R1 margins and were treated with postoperative radiotherapy. Forty-five of 51 cases after planned biopsies (88%) showed infiltrative growth microscopically. CONCLUSION: Tumor size was found to have a major impact on the prognosis of soft tissue sarcomas, emphasizing the importance of early detection and early treatment of these tumors. Most patients suffering from T1 soft tissue sarcomas might be able to avoid adjuvant therapies including radiotherapy and chemotherapy. To achieve good local control with surgery alone, an adequate surgical margin must be achieved even for small lesions.

The Ki-67 proliferation index predicts recurrence-free survival in patients with dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue sarcoma that originates from the dermis or subcutaneous tissue in the skin. While its prognosis is generally favorable, disease recurrence is relatively frequent. Because morbidity after repeated surgery may be significant, an optimized prediction of recurrence-free survival (RFS) has the potential to improve current management strategies. The purpose of this study was to investigate the prognostic value of the Ki-67 proliferation index with respect to RFS in patients with DFSP. We retrospectively analyzed data from 45 patients with DFSP. We calculated the Ki-67 proliferation index as the percentage of immunostained nuclei among the total number of tumor cell nuclei regardless of the intensity of immunostaining. We constructed univariate and multivariate Cox proportional hazards regression models to identify predictors of RFS. Among the 45 patients included in the study, 8 developed local recurrences and 2 had lung metastases (median follow-up: 95.0 months; range: 5.2-412.4 months). The RFS rates at 60, 120, and 240 months of follow-up were 83.8%, 76.2%, and 65.3%, respectively. The median Ki-67 proliferation index was 14%. Notably, we identified the Ki-67 proliferation index as the only independent predictor for RFS in multivariate Cox proportional hazards regression analysis (hazard ratio = 1.106, 95% confidence interval = 1.019-1.200, p = 0.016). In summary, our results highlight the potential usefulness of the Ki-67 proliferation index for facilitating the identification of patients with DFSP at higher risk of developing disease recurrences.

Imatinib Treatment for Locally Advanced or Metastatic Dermatofibrosarcoma Protuberans: A Systematic Review.

Importance: Dermatofibrosarcoma protuberans (DFSP) has the potential for local destruction and recurrence, although it carries a low risk of metastasis. Complete surgical resection with negative margins is considered the gold standard for treatment; however, there are cases that are unresectable owing to tumor extension or size or owing to risk of cosmetic and/or functional impairment. Imatinib treatment has been used for locally advanced or metastatic DFSP. Objective: To evaluate the usefulness of imatinib for treating DFSP. Evidence Review: We conducted a systematic review on the PubMed and Embase databases for articles published from September 2002 through October 2017 using the key words "dermatofibrosarcoma" or "dermatofibrosarcoma protuberans" AND "therapy" AND "imatinib." References within retrieved articles were also reviewed to identify additional studies. Studies of adults with histologically proven DFSP treated with imatinib as monotherapy or as an adjuvant or neoadjuvant therapy to surgery were included. Extracted data were analyzed using descriptive statistics. PRISMA guidelines were followed. All analysis took place October through December 2017. Findings: Nine studies met inclusion criteria; 152 patients were included. The calculated mean patient age was 49.3 years (range, 20-73 years). Calculated mean tumor diameter was 9.9 cm (range, 1.2-49.0 cm). When COL1A1-PDGFß protein translocation (collagen, type 1, alpha 1-platelet-derived growth factor ß) was reported, it was present in 90.9% of patients (111 of 122). Complete response was seen in 5.2% of patients (8 of 152), partial response in 55.2% (84 of 152), stable disease in 27.6% (42 of 152), and progression in 9.2% (14 of 152). Four of the 152 patients (2.6%) were excluded from the analysis owing to unknown or unevaluable response. There were no differences in response rate using 400-mg or 800-mg daily doses (67.5% or 27 of 40 patients for 400-mg dose vs 67.1% or 49 of 73 patients for 800-mg dose complete or partial response; P > .99). Adverse events were present in at least 73.5% of cases (78 of 106); severe adverse events were present in 15.1% of cases (20 of 132). Conclusions and Relevance: Imatinib is a useful directed therapy in patients with DFSP who are not surgical candidates owing to disease extension or significant cosmetic or functional impairment. There seems to be no difference between 400- or 800-mg daily doses.

Dermatofibrosarcoma protuberans with fibrosarcomatous transformation: our experience, molecular evaluation of selected cases, and short literature review.

Dermatofibrosarcoma protuberans with fibrosarcomatous transformation (DFSP-FS) is a higher grade tumor arising from dermatofibrosarcoma protuberans (DFSP). Recent literature highlights its impact on recurrence rates, metastatic rates, and survival. In this article, we aim to describe our experience with 13 cases of DFSP-FS in terms of pathologic findings, molecular alterations, clinical outcomes, management, and also perform a short recent literature review.

Descriptive epidemiology of dermatofibrosarcoma protuberans in the United States, 1973 to 2002.

BACKGROUND: The epidemiology of dermatofibrosarcoma protuberans (DFSP) has not been studied in detail. OBJECTIVE: We sought to describe patterns of DFSP incidence and survival in the United States. METHODS: Data were obtained from 9 population-based cancer registries of the Surveillance, Epidemiology, and End Results Program for 1973 to 2002. RESULTS: DFSP overall annual incidence was 4.2 per million. Incidence increased by 43% (3.1-4.4 per million per year) during the study period, but this increase was restricted to whites. Annual incidence among blacks (6.5 per million) was almost double the incidence among whites (3.9 per million; P < .005, 95% confidence interval of difference 2.02-3.22). Women had higher rates of incidence than men (4.4 vs 4.2 per million per year; P = .052, 95% confidence interval of difference -0.002 to 0.60), except among the elderly. Relative 5-year survival was 99.2% (95% confidence interval 98.3-100%). LIMITATIONS: The Surveillance, Epidemiology, and End Results Program lacks independent verification of diagnoses and case detail. CONCLUSIONS: The racial differences in the incidence of DFSP are significant, and the cause is unknown. Previous literature had suggested that men were more frequently affected, which was not true in our data. The tumor rarely results in death. Epidemiologic investigation using population-based data is important to better understand this disorder.

Molecular and clinical analysis of locally advanced dermatofibrosarcoma protuberans treated with imatinib: Imatinib Target Exploration Consortium Study B2225.

PURPOSE: The cutaneous malignant tumor dermatofibrosarcoma protuberans (DFSP) is typically associated with a translocation between chromosomes 17 and 22 that places the platelet-derived growth factor-B (PDGFB) under the control of the collagen 1A1 promoter. The purpose of this study was to evaluate molecular, cytogenetic, and kinase activation profiles in a series of DFSPs and to determine whether these biologic parameters are correlated with the clinical responses of DFSP to imatinib. PATIENTS AND METHODS: We analyzed the objective radiologic and clinical response to imatinib at 400 mg twice daily in eight patients with locally advanced DFSP and two patients with metastatic disease. RESULTS: Each of eight patients with locally advanced DFSP had evidence of t(17;22) and showed a clinical response to imatinib. Four of these patients had complete clinical responses. The two patients with metastatic disease had fibrosarcomatous histology and karyotypes that were substantially more complex than those typically associated with localized DFSP. One patient with metastatic DFSP and an associated t(17;22) had a partial response to imatinib but experienced disease progression after 7 months of therapy. In contrast, the other patient with metastatic disease had a tumor lacking t(17;22), and there was no clinical response to imatinib. Unexpectedly, there was minimal platelet-derived growth factor receptor-beta phosphorylation in the untreated DFSP, despite the documented presence of a PDGFB autocrine mechanism. CONCLUSION: Imatinib has clinical activity against both localized and metastatic DFSP with t(17;22). However, fibrosarcomatous variants of DFSP lacking t(17;22) may not respond to imatinib.