Dermatofibrosarcoma protuberans: from translocation to targeted therapy

Advanced dermatofibrosarcoma protuberans: an updated analysis of cases from an Indian sarcoma clinic

AIM

Dermatofibrosarcoma protuberans (DFSP) accounts for less than 2% of all soft-tissue sarcomas.

PATIENTS & METHODS

We retrospectively reviewed our database for patients with locally advanced or metastatic DFSP who had presented to our clinic between January 2016 and January 2020.

RESULTS

We identified a total of 14 patients, of whom ten had sarcomatous transformation. Eleven cases had metastatic disease and three were locally advanced. The initial partial response rate to first-line imatinib was 76.9% and the overall median progression-free survival on imatinib was 15 months.

CONCLUSION

We had a high proportion of patients with sarcomatous transformation, in contrast to their relative rarity in the West. While most patients had initial good responses to imatinib, second-line therapies were not as effective.

Long-Term Outcome of Neoadjuvant Tyrosine Kinase Inhibitors Followed by Complete Surgery in Locally Advanced Dermatofibrosarcoma Protuberans

Simple Summary

Wide surgical excision is the standard treatment for dermatofibrosarcoma protuberans. Imatinib mesylate has been reported as an efficient neoadjuvant therapy to surgery in order to reduce tumor size and post-operative relapses for locally advanced or unresectable tumors. The aim of this study was to evaluate the long-term status of patients with advanced dermatofibrosarcoma protuberans treated by neoadjuvant tyrosine kinase inhibitors. Based on the data of 27 patients in our center, locally advanced and unresectable DFSP were efficiently treated with neoadjuvant tyrosine kinase inhibitors followed by complete surgery with micrographic analysis with durable local recurrence disease-free survival and few severe adverse events.

Abstract

In locally advanced dermatofibrosarcoma protuberans (DFSP), imatinib mesylate has been described as an efficient neoadjuvant therapy. This retrospective study included patients with locally advanced DFSP who received neoadjuvant TKI (imatinib or pazopanib) from 2007 to 2017 at Saint Louis Hospital, Paris. The primary endpoint was the evaluation of the long-term status. A total of 27 patients were included, of whom nine had fibrosarcomatous transformation. The median duration of treatment was 7 months. The best response to TKI treatment before surgery, evaluated according to RECIST1.1 on MRI, consisted of complete/partial response (38.5%) or stability (46.2%). DFSP was surgically removed in 24 (89%) patients. A total of 23 patients (85%) were disease-free after 64.8 months of median follow-up (95% confidence interval 47.8; 109.3). One patient developed distant metastases 37 months after surgical tumor resection and finally died. Two patients (7%) did not get surgery because of metastatic progression during TKI treatment, and one patient refused surgery even though the tumor decreased by 30%. Treatment-related adverse events (AE) occurred in 23 patients (85%). Only four patients (imatinib: n = 3, pazopanib: n = 1) had grade ≥3 AE requiring temporary treatment disruption. Neoadjuvant TKI followed by complete surgery with micrographic analysis is an effective strategy for locally advanced and unresectable DFSP, with durable local recurrence disease-free survival.

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. Since 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 a higher risk of developing disease recurrences.

Clinicopathological features of fibrosarcomatous dermatofibrosarcoma protuberans and the construction of a back-propagation neural network recognition model

BACKGROUND

Fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP) is a form of tumor progression of dermatofibrosarcoma protuberans (DFSP) with an increased risk of metastasis and recurrence. Few studies have compared the clinicopathological features of FS-DFSP and conventional DFSP (C-DFSP).

OBJECTIVES

To better understand the epidemiological and clinicopathological characteristics of FS-DFSP.

METHODS

We conducted a cohort study of 221 patients diagnosed with DFSP and built a recognition model with a back-propagation (BP) neural network for FS-DFSP.

RESULTS

Twenty-six patients with FS-DFSP and 195 patients with C-DFSP were included. There were no differences between FS-DFSP and C-DFSP regarding age at presentation, age at diagnosis, sex, size at diagnosis, size at presentation, and tumor growth. The negative ratio of CD34 in FS-DFSP (11.5%) was significantly lower than that in C-DFSP (5.1%) (P = 0.005). The average Ki-67 index of FS-DFSP (18.1%) cases was significantly higher than that of C-DFSP (8.1%) cases (P < 0.001). The classification accuracy of the BP neural network model training samples was 100%. The correct rates of classification and misdiagnosis were 84.1% and 15.9%.

CONCLUSIONS

The clinical manifestations of FS-DFSP and C-DFSP are similar but have large differences in immunohistochemistry. The classification accuracy and feasibility of the BP neural network model are high in FS-DFSP.

A Rare Malignant Disease, Dermatofibrosarcoma Protuberans of the Breast: A Retrospective Analysis and Review of Literature

Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade fibroblastic mesenchymal tumor derived from the dermis. The aim of this retrospective analysis was to summarize the clinicopathological data from our cases and published cases to offer more evidence for the recognition of dermatofibrosarcoma protuberans (DFSP). A total of 6 breast DFSP patients who had received treatment in our hospital were retrospectively enrolled, and detailed clinicopathological data were gathered for analysis. The median age was 29.5 years (ranging from 17 to 42 years). Most cases presented a red or brown-red, mobile, well-circumscribed, protruding, breast mass (ranging from 1 to 3 cm). For histopathology, all cases (6/6) showed a storiform pattern of spindle cells that were positive for CD34 (6/6) and Vimentin (5/6) and negative for smooth muscle actin (0/6) and S-100 protein (0/6). The majority of patients (5/6) underwent wide local excision, with 2 cases treated with radiotherapy. With a median follow-up of 36 months, all 6 patients survived without recurrence or metastasis. The PubMed database was used to search for similar cases. Eventually, 36 cases were included in this review, while cases without detailed clinical information or not reported in English were excluded from the analysis. To summarize, DFSP of the breast is an extremely rare malignancy characterized by spindle tumor cells arranged in a storiform pattern and positivity for CD34. The core needle biopsy is one of the crucial methods for its preoperative diagnosis. Management of DFSP is mainly based on surgical excision. It is prone to local recurrence, so long-term follow-up is required.

Dermatofibrosarcoma protuberance in a black African cohort-a clinicopathologic study

Background

Dermatofibrosarcoma protuberance (DFSP) is the commonest, yet rare, dermal sarcoma globally. There are few reports in the literature of this neoplasm in Nigerians and indeed in sub-Saharan Africa. This study documents our institutional practice observation and compares it with those from other regions of the world.

Methods and materials

This study was a retrospective review of all cases of histologically diagnosed DFSP at the University College Hospital, Ibadan, Nigeria, spanning a period of 27 years (January 1989–December 2016). Data on patient age, gender, tumour location, size, tumour recurrence and metastasis status were obtained from clinical and surgical pathology archival files and records.

Results

Sixty-nine cases of DFSP were recorded over the period reviewed with a male–female ratio of 1.6:1. The mean age of the study population was 39.6 years. The youngest patient was 5-year old, while the oldest was 86 years and the modal age group was the 4th decade. The trunk was the commonest anatomic tumour location. Recurrences were seen in seven cases with recurrence interval ranging from 6 to 240 months. The correlation between tumour size and age was non-significant (r = −0.183; p = 0.182). There was fibrosarcoma-like transformation in three cases (4.3%) studied.

Conclusion

Dermatofibrosarcoma protuberance is rare in our population and occurs more commonly in males and on the trunk. Recurrence can occur beyond the recommended follow-up period of 10 years.

Cancer Stem Cells in Soft-Tissue Sarcomas

Soft tissue sarcomas (STS) are a rare group of mesenchymal solid tumors with heterogeneous genetic profiles and clinical features. Systemic chemotherapy is the backbone treatment for advanced STS; however, STS frequently acquire resistance to standard therapies, which highlights the need to improve treatments and identify novel therapeutic targets. Increases in the knowledge of the molecular pathways that drive sarcomas have brought to light different molecular alterations that cause tumor initiation and progression. These findings have triggered a breakthrough of targeted therapies that are being assessed in clinical trials. Cancer stem cells (CSCs) exhibit mesenchymal stem cell (MSC) features and represent a subpopulation of tumor cells that play an important role in tumor progression, chemotherapy resistance, recurrence and metastasis. In fact, CSCs phenotypes have been identified in sarcomas, allied to drug resistance and tumorigenesis. Herein, we will review the published evidence of CSCs in STS, discussing the molecular characteristic of CSCs, the commonly used isolation techniques and the new possibilities of targeting CSCs as a way to improve STS treatment and consequently patient outcome.

Use of Fluorescence In Situ Hybridization (FISH) in Diagnosis and Tailored Therapies in Solid Tumors

Fluorescence in situ hybridization (FISH) is a standard technique used in routine diagnostics of genetic aberrations. Thanks to simple FISH procedure is possible to recognize tumor-specific abnormality. Its applications are limited to designed probe type. Gene rearrangements e.g., ALK, ROS1 reflecting numerous translocational partners, deletions of critical regions e.g., 1p and 19q, gene fusions e.g., COL1A1-PDGFB, genomic imbalances e.g., 6p, 6q, 11q and amplifications e.g., HER2 are targets in personalized oncology. Confirmation of genetic marker is frequently a direct indication to start specific, targeted treatment. In other cases, detected aberration helps pathologists to better distinguish soft tissue sarcomas, or to state a final diagnosis. Our main goal is to show that applying FISH to formalin-fixed paraffin-embedded tissue sample (FFPE) enables assessing genomic status in the population of cells deriving from a primary tumor or metastasis. Although many more sophisticated techniques are available, like Real-Time PCR or new generation sequencing, FISH remains a commonly used method in many genetic laboratories.

Dermatofibrosarcoma protuberans - the use of neoadjuvant imatinib for treatment of an uncommon breast malignancy: a case report

BACKGROUND

Dermatofibrosarcoma protuberans is a rare soft tissue malignancy that, if left untreated, can be locally destructive and life-threatening. Dermatofibrosarcoma protuberans is uncommon in the breast, and the similarity of its morphologic features with other spindle cell malignancies can make correct identification difficult. Immunohistochemistry and molecular testing can aid in the correct diagnosis when there is diagnostic uncertainty. Imatinib, a selective tyrosine kinase inhibitor, has been used for adjuvant treatment of dermatofibrosarcoma protuberans following surgical resection. When used as a neoadjuvant treatment, imatinib offers the opportunity to decrease tumor size prior to surgery to lessen the chance for disfigurement.

CASE PRESENTATION

We present the case of a Caucasian woman who was 46-year-old when she first noted a mass in her right breast in 2015; she was initially diagnosed as having metaplastic breast carcinoma. Mastectomy and systemic chemotherapy were planned; however, after review of pathology at a referral center, the diagnosis was changed to dermatofibrosarcoma protuberans. She was treated with 4 months of neoadjuvant imatinib with adequate tumor shrinkage to perform breast conservation.

CONCLUSION

This patient's case stresses the importance of correctly diagnosing this rare breast tumor through the histopathologic appearance of dermatofibrosarcoma protuberans, molecular pathogenesis, and immunohistochemistry. These techniques can help differentiate dermatofibrosarcoma protuberans from metaplastic breast carcinoma and other spindle cell lesions of the breast. This is critical, as the treatment options for metaplastic breast carcinoma significantly differ from treatment options for dermatofibrosarcoma protuberans. This case describes the use of imatinib as a neoadjuvant option to reduce preoperative tumor size and improve surgical outcomes.

IGF2/IGF1R Signaling as a Therapeutic Target in MYB-Positive Adenoid Cystic Carcinomas and Other Fusion Gene-Driven Tumors

Chromosome rearrangements resulting in pathogenetically important gene fusions are a common feature of many cancers. They are often potent oncogenic drivers and have key functions in central cellular processes and pathways and encode transcription factors, transcriptional co-regulators, growth factor receptors, tyrosine kinases, and chromatin modifiers. In addition to being useful diagnostic biomarkers, they are also targets for development of new molecularly targeted therapies. Studies in recent decades have shown that several oncogenic gene fusions interact with the insulin-like growth factor (IGF) signaling pathway. For example, the MYB-NFIB fusion in adenoid cystic carcinoma is regulated by IGF1R through an autocrine loop, and IGF1R is a downstream target of the EWSR1-WT1 and PAX3-FKHR fusions in desmoplastic small round cell tumors and alveolar rhabdomyosarcoma, respectively. Here, we will discuss the mechanisms behind the interactions between oncogenic gene fusions and the IGF signaling pathway. We will also discuss the role of therapeutic inhibition of IGF1R in fusion gene driven malignancies.

The efficacy of Mohs micrographic surgery over the traditional wide local excision surgery in the cure of dermatofibrosarcoma protuberans

Usually most patients with dermatofibrosarcoma protuberans (DFSP) may present rather late when the tumor is in protuberant phase due to its rarity and indolent onset. It has a high propensity for local recurrence and destructive nature. Management of DFSP requires a biopsychosocial and Multidisplinary approach regardless of the clinical or immunohistochemical variant. Surgery is the Gold standard management of localized disease. DFSP rarely exhibits any lymphatic or hematogenous dissemination. It is because of its high recurrence rate associated with Wide Local Excision (WLE), the introduction of Mohs micrographic surgery (MMS) has really helped in reducing the rates of recurrence of DFSP. Thus, the aim of this meta-analysis and systemic review is to advocate for MMS over WLE for DFSP and other cutaneous malignancies using DFSP as a prototype. The objective of this study were to conduct a meta-analysis on comparative surgical methods used in the cure of DFSP with regards to WLE verses MMS, to evaluate the cure rates with relation to recurrence rates, offer a recommendation on the various treatment modalities based on the location of lesion, and use of adjuvant therapy in different clinical-medical setups. A comprehensive retrospective analysis search in EMBASE, Google Scholar and Medline (PubMed) for studies published from 2008 to 2018 containing the surgical management of DFSP with WLE verses MMS were reviewed. Five studies of moderate-quality evidence (level B) with a pooled patient load of 684 was analyzed and found for recurrence of DFSP after WLE and MMS to be 9.10% and 2.72% respectively after an average follow-up time for both groups of 5.32 years with a female predominance of 1.58. The trunk is the commonest site for the DFSP lesion which was at 52.80% then the upper and lower extremities zones and the head and neck zones at 31.75% and 15.45% respectively. The pooled adjusted odds ratio (OR) analysis indicated that there was a direct relationship with regards the reduced recurrence rate of DFSP in the MMS group compared to the WLE group (OR:0.31;95%; CI :0.17-0.56). Furthermore, there was significant association between the reduced recurrence rate with the MMS in DFSP patients with a statistical P-value of 0.0001 at 95% CI. The expected increased recurrence rate by zones was in WLE head and neck zone at 38.19% then trunk and extremities zone at 13.34%. In the MMS group it was at of 23.4% as compared to 16.0% in the head and neck zone. Mohs Micrographic Surgery (MMS) is more efficacious in the cure rate and recurrence reduction of DFSP and should be advocated for as first line therapy especially in high recurrence prone zones.

Advances in the Understanding of Skin Cancer: Ultraviolet Radiation, Mutations, and Antisense Oligonucleotides as Anticancer Drugs

Skin cancer has always been and remains the leader among all tumors in terms of occurrence. One of the main factors responsible for skin cancer, natural and artificial UV radiation, causes the mutations that transform healthy cells into cancer cells. These mutations inactivate apoptosis, an event required to avoid the malignant transformation of healthy cells. Among these deadliest of cancers, melanoma and its ‘younger sister’, Merkel cell carcinoma, are the most lethal. The heavy toll of skin cancers stems from their rapid progression and the fact that they metastasize easily. Added to this is the difficulty in determining reliable margins when excising tumors and the lack of effective chemotherapy. Possibly the biggest problem posed by skin cancer is reliably detecting the extent to which cancer cells have spread throughout the body. The initial tumor is visible and can be removed, whereas metastases are invisible to the naked eye and much harder to eliminate. In our opinion, antisense oligonucleotides, which can be used in the form of targeted ointments, provide real hope as a treatment that will eliminate cancer cells near the tumor focus both before and after surgery.

Dermatofibrosarcoma protuberans: A rare and devastating tumor of the vulva

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Biopsies of a large mass are prone to sampling errors and may lead to an incorrect diagnosis.

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MRI imaging of vulvar tumors can aid in surgical planning.

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Large sarcomas of the vulva require a multi-disciplinary approach.

Clinical Utility of In Situ Hybridization Assays in Head and Neck Neoplasms

Head and neck pathology present a unique set of challenges including the morphological diversity of the neoplasms and presentation of metastases of unknown primary origin. The detection of human papillomavirus and Epstein-Barr virus associated with squamous cell carcinoma and newer entities like HPV-related carcinoma with adenoid cystic like features have critical prognostic and management implications. In salivary gland neoplasms, differential diagnoses can be broad and include non-neoplastic conditions as well as benign and malignant neoplasms. The detection of specific gene rearrangements can be immensely helpful in reaching the diagnosis in pleomorphic adenoma, mucoepidermoid carcinoma, secretory carcinoma, hyalinizing clear cell carcinoma and adenoid cystic carcinoma. Furthermore, molecular techniques are essential in diagnosis of small round blue cell neoplasms and spindle cell neoplasms including Ewing sarcoma, rhabdomyosarcoma, synovial sarcoma, biphenotypic sinonasal sarcoma, dermatofibrosarcoma protuberans, nodular fasciitis and inflammatory myofibroblastic tumor. The detection of genetic rearrangements is also important in lymphomas particularly in identifying 'double-hit' and 'triple-hit' lymphomas in diffuse large B cell lymphoma. This article reviews the use of in situ hybridization in the diagnosis of these neoplasms.

Dermatofibrosarcoma protuberans (DFSP) arising from a keloid scar - A case report

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous sarcoma with an indolent early course that may be misdiagnosed for benign skin pathology. In this case-report we highlight an instance of DFSP arising from a keloid scar de novo and present a reconstruction with a local pedicled LD flap. We subsequently appraise the related literature and discuss the diagnostic challenges.

Dermatofibrosarcoma Protuberans

OPINION STATEMENT

Dermatofibrosarcoma protuberans (DFSP) is a slow growing tumor with a very low metastatic potential but with significant subclinical extension and great capacity for local destruction. Thus, the first surgeon approached with such challenging tumor must attempt to cure the patient with a method that spares healthy tissue and ensures an optimal oncological, functional, and esthetic result. The treatment of DFSP often requires a multidisciplinary approach. Depending on location, dermatologic surgeons, surgical oncologists, head and neck surgeons, neurosurgeons, plastic surgeons, and occasionally medical oncologists may be involved with the management. Mohs micrographic surgery (MMS) is the preferred method when available. In our institution, most of the DFSP cases are often advanced cases; thus, dermatologic surgeons obtain clear margins peripherally and other surgical specialties assist with resection of the fascia and any critical deeper structures. When MMS is not available, wide local excision (at least 2- to 3-cm margins of resection) with exhaustive pathologic assessment of margin status is recommended, and it is best to confirm tumor extirpation prior to any reconstruction. Subclinical extension of the tumor could be related to the size; how long it has been growing or histological markers that are unknown right now. No clinical trials comparing MMS vs WLE are available, and further research should be focused on these subjects as well as the use of imatinib and other targeted therapies for recurrent and metastatic tumors and for neoadjuvant treatment.

A patient with germ-line gain-of-function PDGFRB p.N666H mutation and marked clinical response to imatinib

PurposeHeterozygous germ-line activating mutations in PDGFRB cause Kosaki and Penttinen syndromes and myofibromatosis. We describe a 10-year-old child with a germ-line PDGFRB p.N666H mutation who responded to the tyrosine kinase inhibitor imatinib by inhibition of PDGFRB.MethodsThe impact of p.N666H on PDGFRB function and sensitivity to imatinib was studied in cell culture.ResultsCells expressing the p.N666H mutation showed constitutive PDGFRB tyrosine phosphorylation. PDGF-independent proliferation was abolished by imatinib at 1 μM concentration. Patient fibroblasts showed constitutive receptor tyrosine phosphorylation that was also abrogated by imatinib with reduced proliferation of treated cells.This led to patient treatment with imatinib at 400 mg daily (340 mg/m²) for a year with objective improvement of debilitating hand and foot contractures, reduced facial coarseness, and significant improvement in quality of life. New small subcutaneous nodules developed, but remained stable. Transient leukopenia, neutropenia, and fatigue resolved without intervention; however, mildly decreased growth velocity resulted in reducing imatinib dose to 200 mg daily (170 mg/m²). The patient continues treatment with ongoing clinical response.ConclusionTo our knowledge, this is one of the first personalized treatments of a congenital disorder caused by a germ-line PDGF receptor mutation with a PDGFRB inhibitor.