Dermatofibrosarcoma protuberans: a surgical disease with a molecular savior

Clinicopathologic Features and Whole Genome Sequencing of a Primary Osteosarcoma of the Uterus

Primary osteosarcoma (OS) of the uterus is a distinctly rare and aggressive disease with fewer than 20 cases reported worldwide. We describe a case of primary uterine OS with rapid development of pulmonary and brain metastasis in a 50-year-old woman. Histopathologic examination of the uterine tumor showed atypical spindle cells producing an osteoid matrix with calcification in keeping with OS. Despite initial response to doxorubicin and ifosfamide, the patient succumbed to brain metastases just 8 months from diagnosis. Whole genome sequencing was performed on tumor and blood samples to analyze genetic alterations in this highly aggressive tumor. A pathogenic somatic missense mutation resulting in substitution of glutamate for lysine at position 653 within the protein kinase domain of the platelet-derived growth factor receptor beta (PDGFRB) was found. The PDGF pathway is involved in cell proliferation and angiogenesis, and it has been implicated in malignancy. Crucially, this pathogenic mutation may be amenable to PDGFR tyrosine kinase inhibition, representing a possible treatment approach in this rare sarcoma.

Protein kinase inhibitor-based cancer therapies: Considering the potential of nitric oxide (NO) to improve cancer treatment

The deregulation of a wide variety of protein kinases is associated with cancer cell initiation and tumor progression. Owing to their indispensable function in signaling pathways driving malignant cell features, protein kinases constitute major therapeutic targets in cancer. Over the past two decades, intense efforts in drug development have been dedicated to this field. The development of protein kinase inhibitors (PKIs) have been a real breakthrough in targeted cancer therapy. Despite obvious successes across patients with different types of cancer, the development of PKI resistance still prevails. Combination therapies are part of a comprehensive approach to address the problem of drug resistance. The therapeutic use of nitric oxide (NO) donors to bypass PKI resistance in cancer has never been tested in clinic yet but several arguments suggest that the combination of PKIs and NO donors may exert a potential anticancer effect. The present review summarized the current state of knowledge on common targets to both PKIs and NO. Herein, we attempt to provide the rationale underlying a potential combination of PKIs and NO donors for future directions and design of new combination therapies in cancer.

Novel PDGFRB rearrangement in multifocal infantile myofibromatosis is tumorigenic and sensitive to imatinib

Infantile myofibromatosis (IM) is an aggressive neoplasm composed of myofibroblast-like cells in children. Although typically localized, it can also present as multifocal disease, which represents a challenge for effective treatment. IM has previously been linked to activating somatic and germline point mutations in the PDGFRβ tyrosine kinase encoded by the PDGFRB gene. Clinical panel-based targeted tumor sequencing of a tumor from a newborn with multifocal IM revealed a novel PDGFRB rearrangement, which was reported as being of unclear significance. Additional sequencing of cDNA from tumor and germline DNA confirmed a complex somatic/mosaic PDGFRB rearrangement with an apparent partial tandem duplication disrupting the juxtamembrane domain. Ectopic expression of cDNA encoding the mutant form of PDGFRB markedly enhanced cell proliferation of mouse embryo fibroblasts (MEFs) compared to wild-type PDGFRB and conferred tumor-forming capacity on nontumorigenic 10T1/2 fibroblasts. The mutated protein enhanced MAPK activation and retained sensitivity to the PDGFRβ inhibitor imatinib. Our findings reveal a new mechanism by which PDGFRB can be activated in IM, suggest that therapy with tyrosine kinase inhibitors including imatinib may be beneficial, and raise the possibility that this receptor tyrosine kinase might be altered in a similar fashion in additional cases that would similarly present annotation challenges in clinical DNA sequencing analysis pipelines.

Myxoid Dermatofibrosarcoma Protuberans of the Vulva: Case Report of a Rare Variant in an Unusual Location, With Unusual Morphologic and Immunohistochemical Features

Dermatofibrosarcoma protuberans (DFSP) is a low-to-intermediate grade infiltrative dermal neoplasm with a predilection for the trunk and extremities. DFSP in the vulvar region is extremely rare, with fewer than 50 cases reported to date in the literature. The histologic diagnosis of this neoplasm is facilitated by the characteristic storiform pattern of spindle cells with infiltration into the subcutaneous fat in a "honeycomb" pattern. However, morphologic variants including the very rare myxoid DFSP have been recognized that pose significant diagnostic difficulties, especially when they occur at unusual sites. The authors describe a case of myxoid DFSP of the vulva in a 44-year-old woman that was initially misdiagnosed as a neurofibroma. Subsequent excision led to significant challenges in diagnosis due to lack of typical morphology and unusual immunohistochemical staining pattern. Presence of peripheral adipose tissue trapping was noted focally that led to suspicion of DFSP. The diagnosis was confirmed by the detection of the characteristic COL1A1/PDGFB fusion transcript by reverse-transcription polymerase chain reaction. This case underscores the diagnostic challenge presented by variants of DFSP presenting in unusual locations and the value of molecular confirmation of the diagnosis.

A Network-Based Data Integration Approach to Support Drug Repurposing and Multi-Target Therapies in Triple Negative Breast Cancer

The integration of data and knowledge from heterogeneous sources can be a key success factor in drug design, drug repurposing and multi-target therapies. In this context, biological networks provide a useful instrument to highlight the relationships and to model the phenomena underlying therapeutic action in cancer. In our work, we applied network-based modeling within a novel bioinformatics pipeline to identify promising multi-target drugs. Given a certain tumor type/subtype, we derive a disease-specific Protein-Protein Interaction (PPI) network by combining different data-bases and knowledge repositories. Next, the application of suitable graph-based algorithms allows selecting a set of potentially interesting combinations of drug targets. A list of drug candidates is then extracted by applying a recent data fusion approach based on matrix tri-factorization. Available knowledge about selected drugs mechanisms of action is finally exploited to identify the most promising candidates for planning in vitro studies. We applied this approach to the case of Triple Negative Breast Cancer (TNBC), a subtype of breast cancer whose biology is poorly understood and that lacks of specific molecular targets. Our “in-silico” findings have been confirmed by a number of in vitro experiments, whose results demonstrated the ability of the method to select candidates for drug repurposing.

Neoadjuvant treatment of Dermatofibrosarcoma Protuberans of pancreas with Imatinib: case report and systematic review of literature

Dermatofibrosarcoma Protuberans (DFSP) is a rare skin tumor, characterized by frequent local recurrence but is seldom metastatic. It is histologically characterized by storiform arrangement of spindle cells. Cytogenetically, most tumors are characterized by translocation 17:22 leading to overexpression of tyrosine kinase PDGFB which can be targeted with tyrosine kinase inhibitor, Imatinib. We describe the first case of unresectable pancreatic metastases from DFSP treated with neoadjuvant Imatinib and subsequently R0 metastectomy. Additionally, a comprehensive systematic review of DFSP pancreatic metastases and the current published data on the use of Imatinib in DFSP is summarized.

Dermatofibrosarcoma protuberans (DFSP) successfully treated with sorafenib: case report

DFSP is a locally invasive, slow-growing tumor of the subcutaneous tissue that rarely metastasizes but recurs frequently after surgical excision. We report herein a case of highly recurrent, locally invasive DFSP that failed both postoperative radiation therapy and complete trial of Imatinib, but was successfully treated with Sorafenib, which showed unprecedented response.

A Phase I clinical trial of the combination of imatinib and paclitaxel in patients with advanced or metastatic solid tumors refractory to standard therapy

PURPOSE

Pre-clinical data suggest that combining imatinib with traditional cytotoxic chemotherapy may improve imatinib efficacy. We conducted a Phase I study of imatinib in combination with paclitaxel in patients with advanced or metastatic solid tumors.

METHODS

Patients were accrued to the study in a standard 3 + 3 design. Patients were restaged every two cycles, and those with stable disease (SD), or better, continued study treatment without interruption. Maximally tolerated doses (MTDs) and pharmacokinetic profiles of combination imatinib and paclitaxel were assessed.

RESULTS

Fifty-eight patients were enrolled, including 40 in the Phase I dose escalation portion. Alternating dose escalation of imatinib and paclitaxel on a 28-day cycle resulted in MTDs of 800 mg imatinib daily, on days 1-4, 8-11, 15-18, and 22-25, and 100 mg/m(2) paclitaxel weekly, on days 3, 10, and 17. Two expansion cohorts, comprising 10 breast cancer patients and 8 patients with soft-tissue sarcomas, were enrolled at the MTDs. The most common adverse events were flu-like symptoms (64 %) and nausea/vomiting (71 %). The most common Grade 3/4 toxicities were neutropenia (26 %), flu-like symptoms (12 %), and pain (12 %). There were no relevant differences in the pharmacokinetic profiles of either drug when given in combination compared with alone. Thirty-eight subjects were evaluable for response, 18 (47.4 %) of whom experienced clinical benefit. Five patients (13.2 %) had a partial response (PR) and 13 patients (34.2 %) had SD; the average time to progression in those with clinical benefit was 17 weeks (range: 7-28 weeks).

CONCLUSIONS

This combination of imatinib and paclitaxel was reasonably safe and tolerable, and demonstrated evidence of anti-tumor activity. Further exploration in disease-specific Phase II trials is warranted.

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.

Changing pathology with changing drugs: skin cancer

Today skin cancer is mainly treated by surgical interventions. New findings concerning molecular biology and the signaling pathways in epithelial skin cancers such as basal cell carcinoma, squamous cell carcinoma or melanoma, and mesenchymal skin cancers such as angiosarcoma and dermatofibrosarcoma protuberans (DFSP) have identified new molecular targets for a systemic or local treatment approach. For DFSP there is an opportunity already today to reduce the intensity of surgical procedures by pretreatment with targeted therapy. This article highlights important aspects in several skin cancer types.

Dermatofibrosarcoma protuberans (DFSP): predictors of recurrence and the use of systemic therapy

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue malignancy that typically presents with local invasion but rarely metastasizes. We examine clinicopathologic factors associated with disease-free survival (DFS) in patients with primary and recurrent DFSP and evaluate responses to multimodality therapy.

MATERIALS AND METHODS

Patients treated for DFSP were identified in a prospectively maintained database. Clinicopathologic factors associated with DFS were analyzed using univariate and multivariate analysis.

RESULTS

A total of 244 patients with DFSP were identified. Median follow-up was 50 months. A total of 14 patients had local recurrence (LR), and 2 patients had distant recurrence (DR), with a median time to recurrence of 35 months. At time of last follow-up, 70% and 47% of patients showed no evidence of disease (NED) in the primary (n = 197) and recurrent groups (n = 47), respectively. On univariate analysis, tumor location and depth were associated with DFS in the primary group, while margin status (R1 vs. R0) was associated with DFS in the LR group. On multivariate analysis, only depth (primary group) and margin status (LR group), remained significant. Also, 22 patients had therapy other than surgical resection: 14 radiotherapy, 4 tyrosine kinase inhibitor (TKI) only, 2 conventional chemotherapy only, and 2 chemotherapy plus TKI. Responses to other therapies were variable.

CONCLUSIONS

DFS after treatment for DFSP is strongly predicted by tumor depth in the primary setting and margin status in recurrent tumors. The treatment for DFSP in the primary or recurrent setting is excision with negative margins, resulting in low recurrence rates and infrequent metastatic spread. Multimodality treatment, especially TKI use, can be effective, but is not curative.

Imatinib mesylate in children and adolescents with cancer

Imatinib is an inhibitor of the BCR-ABL fusion gene product that characterizes chronic myeloid leukemia (CML), and of the related tyrosine kinases c-KIT and platelet-derived growth factor (PDGF) receptor. The drug is now included as front-line therapy for CML and Philadelphia chromosome-positive acute lymphoblastic leukemia in children and adolescents, though valid concerns about serious late sequelae remain unresolved and are important issues for further study. European and North American consortia have conducted phase I and II clinical trials of imatinib in children and adolescents with brain and other solid tumors that have provided little evidence of efficacy.

Unusual skin tumors: Merkel cell carcinoma, eccrine carcinoma, glomus tumors, and dermatofibrosarcoma protuberans

This article discusses the epidemiology, etiology, presentation, pathology, evaluation and staging, and treatment of unusual skin tumors, such as Merkel cell carcinoma, eccrine carcinoma, glomus tumors, and dermatofibrosarcoma protuberans.

Remission with Imatinib mesylate treatment in a patient with initially unresectable dermatofibrosarcoma protuberans--a case report

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare, malignant dermal mesenchymal neoplasm characterized by a slow, infiltrative growth. These neoplasms have a high tendency to recur locally after surgical excision. However, metastasizing cases are exceedingly rare. Cytogenetically, DFSP is characterized by a t(17;22)(22;q13) aberration with fusion of the COL1A1 gene on chromosome 17 with the PDGFB gene on chromosome 22. Here, we report on a successful treatment of a patient with a targeted therapy using the tyrosine kinase inhibitor Imatinib mesylate in neoadjuvant intention.

PATIENTS AND METHODS

A patient with recurrent and initially unresectable but non-metastatic DFSP of the scalp received Imatinib over 3 months with increasing dosage from 400 mg/day to 800 mg/day orally. Due to the location of the DFSP in our patient, we intended to decrease tumor size preoperatively to allow complete surgical resection. Response to therapy was assessed by computed tomography.

RESULTS

Preoperative treatment with Imatinib resulted in decrease of tumor size by over 60% in the greatest dimension during 3 months of therapy, enabling the complete resection of the DFSP by radical surgery with achieving an acceptable cosmetic result. Surgery was followed by adjuvant Imatinib therapy over 6 months.

CONCLUSIONS

Imatinib mesylate is effective in neoadjuvant treatment of primary unresectable dermatofibrosarcoma protuberans and can be considered as a useful option in the therapy regimen.

Congenital atrophic dermatofibrosarcoma protuberans in a 7-month-old boy treated with Mohs micrographic surgery

Dermatofibrosarcoma protuberans is a rare, malignant, slow-growing, locally invasive tumor of the skin. Although most cases are acquired and diagnosed in adulthood, there have been an increasing number of congenital dermatofibrosarcoma protuberans mimicking benign birthmarks described in the literature. The clinical presentation of this tumor is often one of an indurated exophytic plaque or nodule; however, a rare variant can present as atrophic or sclerotic in nature. We report a case of congenital atrophic dermatofibrosarcoma protuberans of the groin in a 7-month-old boy, successfully treated with Mohs micrographic surgery.

Dermatofibrosarcoma protuberans: recent clinical progress

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumor of low malignant grade characterized by a pattern of slow, infiltrative growth and a marked tendency to recur locally after surgical excision. Wide surgical resection is generally accepted as optimal treatment for DFSP. However, despite optimal surgical management, distant metastases may develop in up to 5% of patients. More than 90% of DFSP are characterized by a reciprocal chromosomal translocation, t(17;22). This rearrangement leads to constitutive activation of the platelet-derived growth factor receptor (PDGFR) as a result of deregulated ligand expression, thus providing a rationale for targeted inhibition of PDGFR as a treatment strategy for patients with unresectable locally advanced or metastatic DFSP.

METHODS

This article reviews the current understanding of DFSP, with emphasis on molecular-level pathogenetic events and their implications for management, and evidence for the role of tyrosine kinase inhibition in improving the outcomes of patients with unresectable locally advanced or metastatic DFSP.

RESULTS

Surgery with wide margins remains the cornerstone in the management of DFSP. Recently, imatinib, a potent, selective inhibitor of the PDGFR alpha and PDGFR beta protein-tyrosine kinases, has been reported to induce complete or partial remissions in most patients treated for advanced DFSP.

CONCLUSIONS

Imatinib is approved for treatment of adult patients with unresectable, recurrent, and/or metastatic DFSP who are not eligible for surgery. Future investigations will determine whether imatinib can also be used in the neoadjuvant setting to reduce tumor volume, thereby allowing resection of very large DFSP that would otherwise not be resectable.

Clinical relevance of molecular genetics to paediatric sarcomas

The application of cytogenetic and molecular genetic analyses to paediatric sarcomas has identified a number of characteristic changes associated with types and subtypes of sarcomas. This has led to increased understanding of the underlying molecular biology of some sarcomas and provided an important adjunct to standard morphological and immunohistochemical diagnoses. Characteristic genetic abnormalities, particularly specific chromosome translocations and associated fusion genes, have diagnostic and in some cases prognostic value. There is also the potential to detect micrometastastic disease. Fusion genes are most readily detected by fluorescence in situ hybridisation and reverse transcription-PCR technologies. The expression profiles of tumours with specific fusion genes are characteristically similar and the molecular signatures of sarcomas are also proving to be of diagnostic and prognostic value. Furthermore, fusion genes and other emerging molecular events associated with sarcomas represent potential targets for novel therapeutic approaches which are desperately required to improve the outcome of children with certain categories of sarcoma, including rhabdomyosarcomas and the Ewing's family of tumours. Increased understanding of the molecular biology of sarcomas is leading towards more effective treatments which may complement or be less toxic than conventional radiotherapy and cytotoxic chemotherapy. Here we review paediatric sarcomas that have associated molecular genetic changes which can increase diagnostic and prognostic accuracy and impact on clinical management.

PDGF Receptors as Targets in Tumor Treatment

Signaling through platelet-derived growth factor (PDGF) receptors contributes to multiple tumor-associated processes. The recent introduction of clinically useful PDGF inhibitors have the last years validated PDGF receptors in malignant and stromal cells as relevant cancer drug targets. Mutational activation of PDGF receptor signaling in malignant cells has been described in some rare tumor types such as dermatofibrosarcoma protuberans, a subset of GISTs, and some hematologic malignancies. Furthermore, expression of PDGF receptors on pericytes is a common characteristic of solid tumors. The clinical efficacy of novel multikinase inhibitors, such as sunitinib and sorafenib, most likely involves targeting of PDGF receptor-dependent pericytes. Preclinical studies suggest that targeting of stromal PDGF receptors might also constitute a novel strategy to enhance tumor drug uptake. Finally, recent studies have implied both pro- and antimetastatic effects of PDGF receptors on malignant and stromal cells. The studies on the roles of PDGF receptors in cancer signaling are thus presently in a dynamic phase where collaborations between oncologists, pathologists, and tumor biologists are predicted to be highly productive.