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

Multiple primary dermatofibrosarcoma protuberans tumors in a single patient with chromosomal microarray analysis: A case report and review

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma with a high propensity for local invasion and recurrence. Although it is a rare event, the occurrence of multiple tumors in a single patient raises a diagnostic dilemma, as metastatic disease should be differentiated from multiple primary malignant events. In more than 90% of DFSP, a pathogenic t(17;22) translocation leads to the expression of COL1A1::PDGFB fusion transcripts. Karyotype analysis, fluorescence in situ hybridization, and RT-PCR can be useful ancillary studies in detecting this characteristic rearrangement, and sequencing of the fusion transcript can be used to support a clonal origin in metastatic and multifocal disease. However, previous reports have demonstrated variable sensitivity of these assays, in part due to the high sequence variability of the COL1A1::PDGFB fusion. Here, we report a patient who developed two distinct DFSP tumors over the course of 7 years. Chromosomal microarray analysis identified distinctive genomic alterations in the two tumors, supporting the occurrence of multiple primary malignant events.

Overcoming Secondary Mutations of Type II Kinase Inhibitors

Type II kinase inhibitors bind in the "DFG-out" kinase conformation and are generally considered to be more potent and selective than type I inhibitors, which target a DFG-in conformation. Nine type II inhibitors are currently clinically approved, with more undergoing clinical development. Resistance-conferring secondary mutations emerged with the first series of type II inhibitors, most commonly at residues within the kinase activation loop and at the "gatekeeper" position. Recently, new inhibitors have been developed to overcome such mutations; however, mutations activating other pathways (and/or other targets) have subsequently emerged on occasion. Here, we systematically summarize the secondary mutations that confer resistance to type II inhibitors, the structural basis for resistance, newer inhibitors designed to overcome resistance, as well as the challenges and opportunities for the development of new inhibitors to overcome secondary kinase domain mutations.

Metastatic Fibrosarcomatous Transformation of Dermatofibrosarcoma Protuberans With Lung Metastasis: A Case Report

Dermatofibrosarcoma protuberans (DFSP) is a low- to intermediate-grade dermal soft tissue malignant tumor (sarcoma) with a high local recurrence rate but low metastatic potential. DFSP is characterized by uniform spindle cell fascicles arranged classically in a storiform pattern and by CD34 immunoreactivity. On gross examination, DFSP usually manifests as a white or yellow soft tissue mass with a smooth outer surface and poor circumscription. In this study, we report a case of DFSP with fibrosarcomatous transformation, a rare but well-known phenomenon encountered in DFSP that is correlated with an increased risk of adverse outcomes in patients with DFSP. A 45-year-old male presented with a progressively enlarging lump on his left shoulder, initially suspected of being a lipoma but diagnosed as a fibrosarcomatous transformation of DFSP. Surgical resection was performed, with the subsequent identification of metastatic sarcoma in pulmonary nodules. Robotic-assisted thoracoscopy excised the nodules, confirming metastatic sarcoma with aggressive behavior. Despite negative adjuvant treatment plans, the patient remains under surveillance with imaging, showing no recurrence in recent scans. Continued follow-up with medical and surgical oncology is planned. DFSP is a rare soft tissue sarcoma characterized by indolent growth and low metastatic potential, except in fibrosarcomatous transformation cases. Molecularly, DFSP is defined by a COL1A1-PDGFB fusion transcript that is targetable with imatinib therapy. Treatment involves wide surgical resection, with adjuvant radiation therapy in select cases. Radiation therapy may be employed in cases with close or positive margins, while conventional chemotherapy has limited utility. Multidisciplinary collaboration is crucial for optimal management. Overall, this case underscores the challenges in diagnosing and managing aggressive sarcomas like fibrosarcomatous DFSP, emphasizing the importance of vigilant surveillance and multidisciplinary collaboration in optimizing patient outcomes. Further research is needed to understand the mechanisms underlying fibrosarcomatous transformation and to explore novel therapeutic avenues for this challenging malignancy.

Fibrosarcomatous Dermatofibrosarcoma Protuberans of the Head

This article highlights the case of a 37-year-old male who presented with a recurrent, exponentially enlarging head mass, emphasizing the diagnostic and therapeutic challenges associated with a very rare type of tumor, fibrosarcomatous dermatofibrosarcoma protuberans (DFSP) of the head. Our patient presented with a rapidly growing head mass, initially diagnosed as a spindle cell tumor, and was managed with surgical excision and skin flap grafting. Follow-up revealed relapse and interval development of hemiparesis and hemisensory loss. MRI revealed tumor recurrence, with compression of the right parietal lobe and superior sagittal sinus. Histopathology revealed stroma with fascicles of spindle cells homogenous to fibrillar cytoplasm, with oval vesicular nuclei. Immunohistochemical staining showed positivity for CD34 and SMA. Oral chemotherapy with imatinib 800 mg/day was started. Follow-up imaging showed a marked reduction in the size of the tumor and resolution of the compression of the underlying brain parenchyma with cystic degeneration and decreased contrast enhancement. Future plans include possible surgical tumor debulking and/or radiation therapy. Although extremely rare, awareness of this tumor, with a multi-disciplinary approach to the management of the case, is vital to maximize treatment outcomes.

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.

Detailed DNA methylation characterisation of phyllodes tumours identifies a signature of malignancy and distinguishes phyllodes from metaplastic breast carcinoma

Phyllodes tumours (PTs) are rare fibroepithelial lesions of the breast that are classified as benign, borderline, or malignant. As little is known about the molecular underpinnings of PTs, current diagnosis relies on histological examination. However, accurate classification is often difficult, particularly for distinguishing borderline from malignant PTs. Furthermore, PTs can be misdiagnosed as other tumour types with shared histological features, such as fibroadenoma and metaplastic breast cancers. As DNA methylation is a recognised hallmark of many cancers, we hypothesised that DNA methylation could provide novel biomarkers for diagnosis and tumour stratification in PTs, whilst also allowing insight into the molecular aetiology of this otherwise understudied tumour. We generated whole-genome methylation data using the Illumina EPIC microarray in a novel PT cohort (n = 33) and curated methylation microarray data from published datasets including PTs and other potentially histopathologically similar tumours (total n = 817 samples). Analyses revealed that PTs have a unique methylome compared to normal breast tissue and to potentially histopathologically similar tumours (metaplastic breast cancer, fibroadenoma and sarcomas), with PT-specific methylation changes enriched in gene sets involved in KRAS signalling and epithelial-mesenchymal transition. Next, we identified 53 differentially methylated regions (DMRs) (false discovery rate < 0.05) that specifically delineated malignant from non-malignant PTs. The top DMR in both discovery and validation cohorts was hypermethylation at the HSD17B8 CpG island promoter. Matched PT single-cell expression data showed that HSD17B8 had minimal expression in fibroblast (putative tumour) cells. Finally, we created a methylation classifier to distinguish PTs from metaplastic breast cancer samples, where we revealed a likely misdiagnosis for two TCGA metaplastic breast cancer samples. In conclusion, DNA methylation alterations are associated with PT histopathology and hold the potential to improve our understanding of PT molecular aetiology, diagnostics, and risk stratification. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Head-and-neck dermatofibrosarcoma protuberans: Survival analysis and Clinically relevant immunohistochemical indicators

BACKGROUND

Head and neck dermatofibrosarcoma protuberans (HNDFSP) is extremely rare and not entirely understood.

OBJECTIVE

To investigate the clinicopathological features of HNDFSP and identify the expression of its clinically relevant indicators, with the expectation of improving the existing treatment strategies.

METHODS

A long-term follow-up of patients with HNDFSP who received treatment between 2000 and 2021 at Shanghai Ninth People's Hospital was conducted. The clinical, histological, and immunohistochemical data of the patients were retrieved and analyzed. The endpoint of the study was the incidence of significant disease-related clinical events (recurrences or metastasis).

RESULTS

A total of 49 patients with HNDFSP were included in the study, with males (92.7%) predominating than females (7.3%). Eighteen patients developed recurrent disease (36.8%) after surgery, and the median time of recurrence was 48 months (interquartile, 20-74 months). Metastasis occurred in two cases (4.1%). Two patients died during follow-up, both with local recurrence, and one of them with intestinal metastasis. Post-operation radiotherapy was administered to eight patients (16.3%) and the effect in local control was remarkable. Age, tumor size, and negative margins with sufficient safety width were the main independent factors affecting the disease-free survival. Several potential targeted therapeutic indicators, including EZH2 (80.0%), EGFR (91.4%), PDGF (97.1%), PD-L1 (77.1%), and VEGF (77.1%), were positively expressed in most tumor samples.

CONCLUSION

HNDFSP is rare, significantly challenging to control locally, and has a worse prognosis with current treatment strategies. Wide local excision and long-term follow-up are needed. Radiotherapy could improve the prognosis of patients with HNDFSP.

COL1A1::PDGFB fusion-associated uterine fibrosarcoma: A case report and review of the literature

BACKGROUND

Mesenchymal neoplasms of the uterus encompass a diverse group of tumors, with varying characteristics and origins, collectively accounting for 8% of uterine malignancies. The most common variants include uterine leiomyosarcoma, low-grade and high-grade endometrial stromal sarcoma, adenosarcoma, and undifferentiated sarcoma. Clinical presentation is often nonspecific and can lead to delayed diagnosis. Uterine sarcomas are generally aggressive, resulting in poorer prognosis compared to carcinomas. Recent advances in molecular techniques, such as next-generation sequencing (NGS), have led to the identification of new subtypes of uterine sarcomas, including COL1A1::PDGFB fusion-associated fibrosarcoma, which has a specific chromosomal translocation t(17;22)(q22;q13). Imatinib, a tyrosine kinase inhibitor (TKI), is an effective treatment for dermatofibrosarcoma protuberans (DFSP), marked by this translocation.

CASE

We present the case of a 42-year-old woman diagnosed with COL1A1::PDGFB fusion-associated uterine fibrosarcoma. The patient underwent total hysterectomy and excision of the tumor, initially misdiagnosed as a low-grade leiomyosarcoma. Subsequent histological examination, immunohistochemistry, and fluorescence in situ hybridization (FISH) confirmed the diagnosis. After 10 months, disease recurrence was detected, and Imatinib therapy was initiated at a dose of 400 mg daily. An allergic reaction led to a temporary discontinuation, but upon resumption with appropriate medication, a positive radiological response was observed. The patient achieved a complete remission after 2 years and is still on Imatinib treatment.

CONCLUSIONS

COL1A1::PDGFB fusion-associated uterine fibrosarcoma is an extremely rare mesenchymal neoplasm. In a case we present herein, we treated a patient with imatinib as first-line medical therapy. The patient is currently in complete remission after 37 months from treatment start. To the best of our knowledge, this represents a unique observation. We also provide a detailed literature review of the published cases so far. Prospective case series are needed to further understand the natural history of these tumors and optimize treatment strategies.

Multi-omic profiling and real time ex vivo modelling of imatinib-resistant dermatofibrosarcoma protuberans with fibrosarcomatous transformation

Dermatofibrosarcoma protuberans (DFSP) is a rare and indolent cutaneous sarcoma, with the risk of aggressive fibro-sarcomatous transformation. Limited effective options are available for un-resectable or metastatic DFSP beyond targeting the oncogenic PDGF pathway with imatinib therapy. We established a patient-derived xenograft (PDX) and cell line model (designated MDFSP-S1) of imatinib-resistant DFSP with fibro-sarcomatous transformation. Whole genome sequencing identified high-level amplification at chromosomes 17 and 22, whilst homozygous deep deletion was demonstrated at chromosome 9 (CDKN2A, CDKN2B, MTAP). RNA sequencing followed by Sanger sequencing confirmed the pathognomonic COL1A1-PDGFB t (17;22) rearrangement in the original tumour, PDX and cell line model. Immunohistochemistry profiles of the PDX model were consistent with the patient's tumour sample (CD34 + /MIB1 + /SOX10- ). Gene set enrichment analysis highlighted top-scoring Hallmark gene sets in several oncogenic signalling pathways, including potentially targetable MTORC1 signalling and angiogenesis pathways. Antiangiogenic agents (sunitinib, regorafenib, pazopanib, axitinib) and the third-generation irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor osimertinib exhibited modest anti-proliferative activity in the cell line, with IC50 values between 1 and 10 µM at 72 h. No significant activity was observed with imatinib, palbociclib, everolimus, olaparib, gefitinib and erlotinib (IC50 all > 10 µM). In conclusion, we established MDFSP-S1, a new PDX and cell line model of imatinib-resistant DFSP with fibro-sarcomatous transformation.

Establishment and characterization of NCC-DFSP4-C1: a novel cell line from a patient with dermatofibrosarcoma protuberans having the fibrosarcomatous transformation

Dermatofibrosarcoma protuberans (DFSP) is a superficial low-grade sarcoma, genetically characterized by a fusion gene in collagen type I α (COL1A1) gene and platelet-derived growth factor subunit β (PDGFB). DFSP is locally aggressive and does not typically metastasize. However, DFSP with fibrosarcomatous transformation, which occurs in 7-16% of DFSP cases, demonstrates a poor prognosis than classic DFSP with a higher local recurrence rate and metastatic potential. Although imatinib, a PDGF receptor inhibitor, is a potent therapeutic agent for classic DFSP, it is less effective for DFSP with fibrosarcomatous transformation. The development of definitive chemotherapies for DFSP with fibrosarcomatous transformation is required. Patient-derived tumor cell lines are indispensable tools for preclinical research to discover novel therapeutic agents. However, only seven cell lines were derived from DFSP, out of which only two were established from DFSP with fibrosarcomatous transformation. Hence, in the present study, we established a novel DFSP cell line, NCC-DFSP4-C1, from a surgically resected DFSP tumor specimen with fibrosarcomatous transformation. NCC-DFSP4-C1 harbored an identical COL1A1-PDGFB fusion gene as its donor tumor. NCC-DFSP4-C1 cells retained the morphology of their donor tumor and demonstrated constant proliferation, spheroid formation, and invasion capability in vitro. By screening a drug library, we found that bortezomib and romidepsin demonstrated the strongest suppressive effects on the proliferation of NCC-DFSP4-C1 cells. In conclusion, we report a novel cell line of DFSP with fibrosarcomatous transformation, and demonstrate its utility in the development of novel therapeutic agents for DFSP.

Dermatofibrosarcoma protuberans: a case report of an abdominal wall mass and review of the literature

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing malignancy that often presents with an ambiguous clinical presentation due to its nonspecific findings. We present the case of a 41-year-old male who presented with a slow-growing mass on his abdomen that became protuberant and firm, prompting his desire to pursue excision. Upon return of histologic examination, the specimen was noted to be DFSP. DFSP is a rare cutaneous neoplasm that originates from the dermis and invades the underlying tissue creating a classic protuberant appearance. In some cases, chemotherapy and radiation may be indicated based on margins and locations. The sarcoma is notoriously complicated with early recurrence, making the disease process difficult to control. Surgeons should be familiar with this malignancy due to the indication of additional nonsurgical treatments and the necessity for long-term follow-up for surveillance of recurrence.

Targeted therapy and immunotherapy for orbital and periorbital tumors: a major review

Traditionally, for patients who are poor candidates for surgery and/or radiotherapy, palliative chemotherapy is often offered but with significant toxic side effects. However, recent advancements in our understanding of tumor biology and molecular genetics have brought new understanding to the molecular pathways of certain tumors and cancers. This has ushered in a new era of precision medicine specific to a tumor or cancer treatment pathway (targeted therapy) or directed to host-tumor responses (immunotherapy). This article will focus on recent updates in the application of available targeted and immunotherapy for managing orbital and periorbital tumors and tumor-like conditions, which include cutaneous basal cell carcinoma, cutaneous squamous cell carcinoma, cutaneous melanoma, Merkel cell carcinoma, sebaceous gland carcinoma, solitary fibrous tumor, dermatofibrosarcoma protuberans, orbital meningioma, neurofibromatosis, Langerhans cell histiocytosis, ocular adnexal lymphoma, orbital lymphatic malformation, and adenoid cystic carcinoma.

Dermatofibrosarcoma protuberans of the scalp: Surgical management in a multicentric series of 11 cases and systematic review of the literature

BACKGROUND

Dermatofibrosarcoma protuberans is a rare, slow-growing soft-tissue malignancy originating in the dermis that is characterized by an infiltrating growth pattern with a marked tendency of local recurrence. Complete surgical resection with pathological margin clearance must be achieved to reduce the risk of tumor recurrence. Resulting defects often require extensive reconstructive procedures. Dermatofibrosarcoma protuberans of the scalp poses particular challenges owing to the proximity to the face and brain. This study aims to evaluate treatment options and proposes an algorithm for management of scalp dermatofibrosarcoma protuberans based on a multicentric case series and systematic review of the literature.

METHODS

A retrospective multicentric chart analysis of 11 patients with scalp dermatofibrosarcoma protuberans who presented within the last 20 years was performed regarding demographic data, pathological tumor characteristics, and surgical management (resection and reconstruction). Additionally, a further 42 patients (44 cases) were identified through a systematic Preferred Reporting Systems for Systematic Reviews and Meta-Analysis-based review of the literature searching the Medline and Embase databases.

RESULTS

In total, 30 cases were classified as primary and 20 cases as recurring scalp dermatofibrosarcoma protuberans (data from 5 cases were missing). The median tumor size was 24 cm2 (interquartile range 7.8-64), and the median defect size was 55.8 cm2 (interquartile range 48-112). Recurring scalp dermatofibrosarcoma protuberans was more often associated with invasion of deeper layers and required more extensive tumor resection to achieve negative margins. Within the subgroup that was managed with peripheral and deep en face margin assessment, no recurrence was observed. Most patients required local (41. 8%) or free flap (27.8%) reconstruction after dermatofibrosarcoma protuberans resection.

CONCLUSION

Whenever possible, peripheral and deep en face margin assessment-based techniques should be preferred for resection of scalp dermatofibrosarcoma protuberans because they provide superior oncological safety while preserving uninvolved tissue. Patients with locally advanced and recurring scalp dermatofibrosarcoma protuberans often require multidisciplinary treatment including neurosurgery, radiotherapy, and microvascular reconstructive surgery and should be referred to a specialized center.

Epidemiological trends and survival outcomes for dermatofibrosarcoma protuberans of the head and neck region

BACKGROUND

Given the rarity of dermatofibrosarcoma protuberans (DFSP) of the head and neck, the incidence and prognosis specific to this region are poorly defined. The purpose of this study was to determine epidemiology, clinicopathological characteristics, and prognostic factors of patients with DFSP of the head and neck region, using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

A cohort analysis was performed for primary head and neck DFSP reported to the SEER database between 2000 and 2018. Overall survival was determined using Kaplan-Meier analysis while Cox regression modeling was used to examine predictive factors.

RESULTS

A total of 681 cases were reported to the SEER database between 2000 and 2018. Incidence rates decreased over time. Overall survival was 94%, and disease-specific survival was 99% at 5 years. Cases of head and neck DFSP were found to occur more frequently in males. There was no difference in incidence rates between White patients and Black patients. Age ≥ 60 years old, tumor size, and living location were the most significant predictors of overall survival.

CONCLUSIONS

This analysis of DFSP of the head and neck demonstrates a downward trend in incidence, higher age-standardized incidence in males, and similar race-based incidences, which differs from data reported on DFSP of other anatomic locations.

Case Report: A case of COL1A1–PDGFB fusion uterine sarcoma at cervix and insights into the clinical management of rare uterine sarcoma

COL1A1–PDGFB gene fusion uterine sarcoma is an especially rare malignant mesenchymal tumor that was previously classified as an undifferentiated uterine sarcoma due to the lack of specific features of differentiation. Till now, only five cases have been reported, and here we presented another case recently diagnosed in a Chinese woman who had vaginal bleeding. She presented with a cervical mass at the anterior lip of the cervix invading the vagina and was treated with laparoscopic total hysterectomy plus bilateral salpingo-oophorectomy (TH+BSO) and partial vaginal wall resection with the final pathology of COL1A1–PDGFB fusion uterine sarcoma. Our aim is to emphasize the importance of differential diagnosis of this rare tumor, as early precise diagnosis may allow patients to benefit from the targeted therapy imatinib. This article also serves as further clinical evidence of this disease, serving to increase clinical awareness of this rare sarcoma to avoid misdiagnosis.

Targeted therapies for the treatment of soft tissue sarcoma

Soft tissue sarcomas are rare malignant tumors derived from mesenchymal cells that have a high morbidity and mortality related to frequent occurrence of advanced and metastatic disease. Over the past two decades there have been significant advances in the use of targeted therapies for the treatment of soft tissue sarcoma. The ability to study various cellular markers and pathways related to sarcomagenesis has led to the creation and approval of multiple novel therapies. Herein, we describe the current landscape of targeted medications used in the management of advanced or metastatic soft tissue sarcomas, excluding GIST. We distinguish three categories: targeted therapies that have current US Food and Drug Administration (FDA) approval for treatment of soft tissue sarcoma, non-FDA approved targeted therapies, and medications in development for treatment of patients with soft tissue sarcoma.

Recurrent Dermatofibrosarcoma Protuberans of the Head and Neck: a Case Series

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous sarcoma that develops from dermal fibroblasts and spreads within the dermis and subcutaneous fat. It is locally aggressive, with a high local recurrence rate after excision but has extremely low metastatic potential. In the case of recurrent tumors, surgical excision with adequate margins is the gold standard treatment and may require adjuvant radiotherapy or chemotherapy in some cases. We conducted a retrospective analysis of individuals with dermatofibrosarcoma protuberance of the head and neck region that had treatment at our facility between 2016 and 2021. We gathered the data on the surgical techniques, reconstructive techniques used, histopathological features, adjuvant therapy, and outcomes. We treated three patients with head and neck dermatofibrosarcoma protuberance: one scalp lesion and two on the cheek. All three patients had recurrent tumors, two of whom were treated elsewhere for the primary lesion. One patient underwent surgery for a benign spindle cell tumor of the right cheek, but a final histopathological examination revealed dermatofibrosarcoma protuberance, and the tumor recurred within 3 months. The duration of recurrence is between 3 and 24 months. The size of the tumor ranges from 7.2 to 10.5 cm. The wide local excision margins range from 2 to 4 cm. Reconstruction ranges from split skin graft to regional flap. Inadequate margins raise the possibility of local recurrence in dermatofibrosarcoma protuberance.

A Case of COL1A1-PDGFB Fusion Uterine Sarcoma

COL1A1-PDGFB gene fusion uterine sarcoma is a recently described entity which shows some overlapping features with dermatofibrosarcoma protuberans. To date, only 4 cases have been reported in the literature. Due to its rarity, succinct clinicopathologic characteristics are yet to be established. We report a fifth case initially mistaken as a uterine fibroid which histologically proved to be a CD34 + high-grade spindle cell proliferation which on fluorescence in situ hybridization analysis displayed COL1A1-PDGFB gene rearrangement. With this case description we hope to raise awareness and aid in the characterization of this emerging entity.

Tyrosine kinase inhibitors versus radiation therapy in unresectable dermatofibrosarcoma protuberans (DFSP): A narrative systematic review

BACKGROUND

In unresectable dermatofibrosarcoma protuberans (DFSP), no clear guideline exists regarding the use of tyrosine kinase inhibitors (TKI) versus radiotherapy. This study reviews current literature regarding TKI and radiotherapy in unresectable DFSP.

METHODS

Following PROSPERO registration (CRD42021232508), a systematic literature search was performed including all studies reporting clinical results of TKI and/or radiotherapy in the treatment of unresectable DFSP. A narrative synthesis was used to compare patient characteristics, outcomes, and adverse effects.

RESULTS

Of 1345 screened studies, 14 were included for review. Patient age ranged 18-77 years and 55% were male. Radiotherapy patients exhibited lower grade disease than TKI patients. Overall clinical benefit following TKI ranged from 70% to 96%. Radiotherapy patients exhibited control or resolution on last follow-up in 90% of cases. Radiotherapy adverse effects were mild, while TKI adverse effects were more severe and managed with dose reduction.

CONCLUSION

TKI may be employed in unresectable DFSP of all histology types whereas radiation alone may be limited to low-grade and classic-type DFSP. TKI may cause more severe adverse effects compared to radiation alone.

Oncological efficiency of wide local excision in dermatofibrosarcoma protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a slow-growing, low- to intermediate-grade malignant sarcoma. Its optimal treatment is resection with wide margins; the likelihood of local control associated with this procedure exceeds 90%. The probability of regional or distant metastases is <5%.

OBJECTIVE

We examined the clinical, epidemiological, and pathological features, the treatment types, and outcomes of patients to investigate the width of safe surgical margins (SM) and how the width of SMs affected recurrence in DFSP.

METHODS

We retrospectively examined the records of 60 patients who were initially operated on with wide local excision for DFSP in the period 2008-2019. Optimal cutoff points for SMs were calculated with the receiver operating characteristic curve analysis and found as 1.925 cm histopathologically and 2.26 cm macroscopically.

RESULTS

During the mean 89.6-month follow-up, local recurrence was seen in 36.7% and distant metastasis in 20% of the patients. Recurrences were significantly related to peripheral resection margins. Analysis by histopathologic cutoff points showed that the local recurrence rate was 84% when SM was ≤1.925 cm, but only 2.85% when >1.925 cm (p = 0.002). Recurrence-free survival was 40.92 months when SM was ≤1.925 cm and 225.75 months when s >1.925 cm (p<0.001). Analysis by macroscopic cutoff points showed that the local recurrence rate was 95.5% when SM was ≤2.26 cm, but only 4% when >2.26 cm (p = 0.001). Recurrence-free survival was 43 months when SM was ≤2.26 cm and 222 months when >2.26 cm (p<0.001). In metastatic patients, progression-free survival was 9 months with cytotoxic chemotherapy, whereas 38.4 months with tyrosine kinase inhibitor (imatinib) (p = 0.002).

CONCLUSION

This study showed SMs >2.5 cm to be sufficiently safe for WLE and optimized the balance among safe margin width, reconstruction need, and surgical morbidity. In metastatic DFSP patients, tyrosine kinase inhibitor imatinib is more effective than cytotoxic chemotherapy for progression-free survival.

Outcome After Surgical Treatment of Dermatofibrosarcoma Protuberans (DFSP): Does it Require Extensive Follow-up and What is an Adequate Resection Margin?

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumour of indeterminate malignant potential. The mainstay treatment for DFSP is surgical resection. Given the reported high local recurrence rate, the ideal resection margin for DFSP is unclear. The purpose of this study was to ascertain the local recurrence and metastatic rate of DFSP and DFSP with fibrosarcomatous degeneration (FS-DFSP), with specific attention to margin status in an attempt to address the issue of margin adequacy.

METHODS

Patients treated for DFSP at a single sarcoma centre were identified from a prospective database. DFSP and FS-DFSP patients with and without prior surgery were included. Patients were followed after surgery to monitor complications, local recurrence and metastasis.

RESULTS

The study included 200 patients: 166 patients with DFSP and 34 patients with FS-DFSP. In the DFSP group, nine patients (5.4%) had positive margins, one case (0.6%) developed local recurrence (LR) and no patients developed distant metastases. In the FS-DFSP group, seven patients (20.6%) had positive margins, six patients (17.6%) developed local recurrence (LR) and eight patients (23.5%) developed distant metastases, of which three (37.5%) were in the lungs, one (12.5%) in bone and four (50%) in other soft tissue sites.

DISCUSSION AND CONCLUSION

Local recurrence and metastases are extremely rare in patients with DFSP. Achieving a negative as opposed to a wide surgical margin may be sufficient to avoid local recurrence of most DFSP. We suggest that no ongoing surveillance for local or systemic relapse is required for DFSP patients after negative margin resection. For FS-DFSP, we recommend the same surveillance schedule, based on tumour grade, as other soft tissue sarcoma.

Comparison of the Basal Cell Carcinoma (BCC) Tumour Microenvironment to Other Solid Malignancies

Basal cell carcinoma (BCC) is the most common form of skin cancer, contributing to nearly a third of new cancer cases in Western countries. Most BCCs are considered low risk "routine" lesions that can either be excised through surgery or treated with chemotherapeutic agents. However, around 1-2% of BCC cases are locally aggressive, present a high risk of metastasis, and often develop chemoresistance, termed advanced BCC. There currently exists no animal model or cell line that can recapitulate advanced BCC, let alone intermediate-risk and high-risk early BCC. We previously found that aggressive BCC tumours presented a Th2 cytokine inflammation profile, mesenchymal stem cell properties, and macrophage-induced tumoral inflammation. In this study, we aimed to identify potential BCC "relatives" among solid-organ malignancies who present similar immune cell proportions in their microenvironment compositions. Using immune cell type deconvolution by CIBERSORTx, and cell type enrichment by xCell, we determined three cancers with the most similar tumour microenvironments as compared to BCC. Specifically, chromophobe renal cell carcinoma, sarcoma, and skin cutaneous melanoma presented significance in multiple cell types, namely in CD4+ T lymphocytes, gammadelta T lymphocytes, and NK cell populations. Consequently, further literature analysis was conducted to understand similarities between BCC and its "relatives", as well as investigating novel treatment targets. By identifying cancers most like BCC, we hope to propose prospective druggable pathways, as well as to gain insight on developing a reliable animal or cell line model to represent advanced BCC.

Regorafenib for the Treatment of Sarcoma

OPINION STATEMENT

Sarcomas are a rare group of tumors with many subtypes, conventionally classified into soft-tissue sarcomas and bone sarcomas. Chemotherapeutic regimens form the mainstay of systemic therapy but are not well defined beyond the first-line setting and clinical outcomes are variable. Tyrosine kinase inhibitors (TKIs), with a broad inhibition profile which have been shown to target tumor angiogenesis, have an established role in the treatment of sarcomas without characteristic driver alterations. One such TKI, regorafenib, has been evaluated in sarcomas and clinical data are discussed in this review. An overview of regorafenib data from five phase 2 and one phase 1b clinical trials in over 10 sarcoma subtypes (both soft-tissue and bone) in adult and pediatric patients is reviewed. Regorafenib demonstrated clinical benefit in patients with non-adipocytic soft-tissue sarcomas, osteosarcoma and Ewing sarcoma who had progressed on prior therapy. Patients with otherwise limited treatment options may therefore benefit from regorafenib therapy.

Pediatric Non-Rhabdomyosarcoma Soft Tissue Sarcomas: Standard of Care and Treatment Recommendations from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

This paper describes the standard of care for patients with non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) and the therapeutic recommendations developed by the European paediatric Soft tissue sarcoma Study Group (EpSSG). NRSTS form a very mixed group of mesenchymal extraskeletal malignancies. Their rarity, heterogeneity, and aggressiveness make the management of children and adolescents with these tumors complex and challenging. The overall cure rate for patients with NRSTS is around 70%, but survival depends on several prognostic variables, such as histotype and tumor grade, extent of disease and stage, tumor size, and tumor site. While surgery remains the mainstay of treatment for most of these tumors, a multimodal therapeutic approach including radiotherapy and chemotherapy is required in many cases. The EpSSG NRSTS 2005 study was the first prospective protocol tailored specifically to NRSTS. Together with the ARST0332 study developed by the North-American Soft Tissue Sarcoma Committee of the Children's Oncology Group (COG), the EpSSG NRSTS 2005 study currently represents the benchmark for these tumors, establishing risk-adapted standards of care. The EpSSG has developed common treatment recommendations for the large group of adult-type NRSTS (including synovial sarcoma), and specific treatment recommendations for other particular adult-type histologies (ie, alveolar soft-part sarcoma, clear cell sarcoma and dermatofibrosarcoma protuberans); other highly malignant tumors with a biology and clinical behavior differing from those of adult-type NRSTS (ie, rhabdoid tumors and desmoplastic small round cell tumor); and soft tissue tumors of intermediate malignancy (ie desmoid-type fibromatosis, inflammatory myofibroblastic tumors, and infantile fibrosarcoma). New effective drugs are needed for patients whose NRSTS carries the worst prognosis, ie, those with unresectable tumors, metastases at diagnosis, or relapsing disease. Progress in this area relies on our ability to develop international integrated prospective collaborations, both within existing pediatric oncology networks and, importantly, between the communities of specialists treating pediatric and adult sarcoma.

Dermatofibrosarcoma Protuberans: What Is This?

Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive dermal-based sarcoma. Metastatic potential is extremely low, primarily in the setting of fibrosarcomatous transformation. DFSP is characterized by a t(17;22) (q22;q13) translocation that results in active PDGFB signaling. Surgical resection with negative margins (typically including the underlying fascia) is the potentially curative treatment. Delayed wound closure should be considered for cases requiring extensive resection or tissue rearrangement. Tyrosine kinase inhibitors, such as imatinib, have shown response rates of 50% to 60% in patients with locally advanced or metastatic disease. Radiation can be useful for residual or recurrent diseases.

The Molecular Biology of Soft Tissue Sarcomas: Current Knowledge and Future Perspectives

Simple Summary

Over the past 20 years, significant advances in the field of genetics and molecular biology have led to the dismantlement of multiple subtypes of sarcomas. As a result, molecular approaches nowadays play a critical role in the diagnosis, prognostic classification, and therapeutic management of numerous mesenchymal tumor subtypes. This review of the current literature illustrates the main uses of molecular biology in the field of soft tissue sarcomas and the future challenges that remain to be addressed.

Abstract

Soft tissue sarcomas are malignant tumors of mesenchymal origin, encompassing a large spectrum of entities that were historically classified according to their histological characteristics. Over the last decades, molecular biology has allowed a better characterization of these tumors, leading to the incorporation of multiple molecular features in the latest classification of sarcomas as well as to molecularly-guided therapeutic strategies. This review discusses the main uses of molecular biology in current practice for the diagnosis and treatment of soft tissue sarcomas, in addition to perspectives for this rapidly evolving field of research.

The European MAPPYACTS Trial: Precision Medicine Program in Pediatric and Adolescent Patients with Recurrent Malignancies

ABSTRACT

MAPPYACTS (NCT02613962) is an international prospective precision medicine trial aiming to define tumor molecular profiles in pediatric patients with recurrent/refractory malignancies in order to suggest the most adapted salvage treatment. From February 2016 to July 2020, 787 patients were included in France, Italy, Ireland, and Spain. At least one genetic alteration leading to a targeted treatment suggestion was identified in 436 patients (69%) with successful sequencing; 10% of these alterations were considered "ready for routine use." Of 356 patients with follow-up beyond 12 months, 107 (30%) received one or more matched targeted therapies-56% of them within early clinical trials-mainly in the AcSé-ESMART platform trial (NCT02813135). Overall, matched treatment resulted in a 17% objective response rate, and of those patients with ready for routine use alterations, it was 38%. In patients with extracerebral tumors, 76% of actionable alterations detected in tumor tissue were also identified in circulating cell-free DNA (cfDNA).

SIGNIFICANCE

MAPPYACTS underlines the feasibility of molecular profiling at cancer recurrence in children on a multicenter, international level and demonstrates benefit for patients with selected key drivers. The use of cfDNA deserves validation in prospective studies. Our study highlights the need for innovative therapeutic proof-of-concept trials that address the underlying cancer complexity. This article is highlighted in the In This Issue feature, p. 1171.

Kutane Sarkome – nicht alle sind wirklich selten, die meisten „low risk“

Die biologische und morphologische Vielfalt der Weichteilmalignome, der Sarkome, ist enorm.

Diese Übersicht fokussiert deshalb auf die 5 am häufigsten vorkommenden Weichteilmalignome. Betrachtet werden soll dabei, was der Kliniker wissen muss, was neu ist und welche Fallstricke es gibt. Ziel dieses Artikels ist es dabei, eine Übersicht zu geben sowie die Konzeptbildung darüber, womit man es im Wesentlichen zu tun hat.

Dermatofibrosarcoma Protuberans in Children

OPINION STATEMENT

Paediatric dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue malignant tumour which displays aggressive local behaviour and has low metastatic potential. The diagnosis is often delayed as DFSP is usually mistaken for other skin conditions, particularly in the early stages of disease. DFSP tends to follow an indolent course after the initial presentation with what is often described as a "rubbery lump". As the disease progresses, the lump tends to enlarge, change colour, and exhibit a more nodular consistency. In rare cases, DFSP can present as an ulcerated exophytic lesion or a depressed area of skin, making diagnosis even more challenging. A high index of suspicion is warranted for early diagnosis, and referral to a specialist unit with expertise in both oncologic resection and reconstruction. DFSP tumours arise from the dermis and grow with finger-like projections. Therefore, in cosmetically sensitive or functionally important locations, an excision and analysis technique that assesses all excision margins is the gold standard of care. Slow Mohs technique performed with en bloc excision is a well-tolerated option for oncologic resection of the tumour. Mohs technique can also be considered but can be challenging in children for reasons explained below. As an alternative, depending on the anatomical location, tumours can be excised with a wide local excision. While an excision technique that incorporates the deep fascia with a 3-cm peripheral margin is acceptable in adults, planning of the excision margin in children should involve consideration of preoperative imaging with MRI, site of the tumour, age, and physical built of the child. Patients should be offered all treatment options considering the local outcomes, available expertise, and cost. A multidisciplinary approach and good communication between team members is crucial. Close collaboration with a pathologist who is familiar with sectioning technique that allows margin control is of paramount importance. Soft tissue reconstruction should be performed immediately after oncologic clearance, although a staged approach may be required. Adjuvant radiotherapy should be avoided in children due to the long-term risk of secondary malignancies and potential for growth disruption.

S, Ninutha S, Dasappa L, MC SB, KN L, AH R, LK R, Saldanha S. Soft Tissue Sarcomas with Special Reference to Molecular Aberration, Chemotherapy, and Recent Advances: A Review Article

Soft tissue sarcomas (STS) are a diverse group of rare solid tumors of mesenchymal cell origin with distinct clinical and pathological features. They account for less than 1% of all adult malignancies and 15% of pediatric neoplasms. They include over hundreds of different histological subtypes. Many of these subtypes can occur at any age and are not confined to a specific site. Each subtype displays variable clinical behavior. Low incidence, variable presentation, behavior, and long-term outcomes further make it challenging to treat. There are multiple ongoing trials that focus on the anatomic site and histologic subtype to tailor the treatment. Further rarity of each histotype is a major barrier to recruit patients to randomized controlled trials. A multidisciplinary approach is mandatory in all cases of soft tissue sarcomas.

The purpose of this review is to thoroughly understand the existing literature on history, incidence, epidemiology, etiology, histology, pathogenesis, diagnostic modalities, prognosis, management, and post treatment surveillance of STS. Uterine sarcomas, gastrointestinal stromal tumors (GIST), and pediatric sarcomas are not included here. It briefly highlights various molecular aberrations, changes in staging as per the American Joint Committee on Cancer (AJCC) 8, drugs that are used off-label in specific subtypes of sarcoma along with the recent advances. The classification of STS is undergoing continuous evolution. A wide variety of subtypes can only be diagnosed accurately with sophisticated molecular diagnostic tests and with the involvement of expert geneticists and pathologists to interpret it.

There is no clarity on tailoring the treatment of STS to date. There is always a question on how best we can incorporate chemotherapy and radiotherapy along with surgery as a part of multimodality treatment. The heterogeneity of STS has hindered the development of robust, evidence-based treatment strategies, and our therapeutic approach is neither histology-specific nor widely standardized. Increased knowledge about sarcoma biology could help to discover new and more effective treatment strategies and help overcome the therapeutic challenge imposed by this deadly disease. Continued collaboration among various sarcoma centers globally will be of prime importance to optimize STS management. This will allow studies to be both sufficiently large and reasonably focused to generate evidence that is clinically meaningful in specific STS patient populations.

Dermatofibrosarcoma Protuberans Presenting in a Patient With Neurofibromatosis Type 1: Potential Implications on Treatment

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma. Neurofibromatosis type 1 (NF1) is a neurocutaneous syndrome that affects multiple organ systems. We present the case of a 47-year-old African American male with a two-year history of a slowly enlarging right lower back lesion. Upon workup, the 3 × 2 cm mass was biopsied confirming a diagnosis of DFSP. This was identified in concert with axillary freckling, café-au-lait spots, and pedunculated plaques evaluated with biopsy. The findings were consistent with neurofibromas, leading to a new diagnosis of NF1. The patient was definitively treated with wide local excision of the DFSP lesion without tumor recurrence over six years. DFSP has a favorable prognosis when treated with wide local excision and negative surgical margins. However, lesions may recur with inadequate margins. Although deferred in our patient, treatment with imatinib mesylate, a tyrosine kinase inhibitor, may be employed in the setting of advanced disease, metastasis, positive surgical margins, or irresectable locations. Imatinib has also been used to treat NF1. Hence, we posit that the concomitant presentation of these two disease entities in our patient highlights a potentially unique treatment with imatinib mesylate. To our knowledge, this is the second reported case of both entities in the same patient.

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.

Diagnostic Difficulties and Complexities in the Management of Dermatofibrosarcoma Protuberans in the Breast: A Case Report and Review of the Literature

Dermatofibrosarcoma protuberans (DFSP) is an extremely rare sarcoma with an incidence between 0.8-5.0 cases per one million persons per year. DFSP accounts for less than 0.1% of all malignancies and approximately 1-6% of all soft tissue sarcomas. Only a few cases of DFSP have been found within the breast tissue. We report a case of DFSP in a 30-year-old female within the left breast. The sarcoma presented as a painless, rubbery, mobile lump that gradually increased in size. It was initially identified on an ultrasound scan and subsequently confirmed with MRI and core biopsy. DFSP is a rare condition and treatment guidelines are not well established. The current recommendation is for surgical excision with 2-cm margins. Mastectomy may be considered in some circumstances. In our case, the aim was for surgical resection with 2-cm margins at both breast tissue and skin, but insufficient margins were taken. The recommendation for re-excision of the inadequate margins was declined. It is uncertain what the implications of this are given the lack of research on DFSP in the breast. Therefore, close surgical surveillance will be imperative. We present this case to highlight the difficulties associated with the diagnosis, treatment, and management of DFSP due to the lack of literature on this disease.

Management of dermatofibrosarcoma protuberans

PURPOSE OF REVIEW

Provide an up to date review of the diagnosis, workup and treatment of dermatofibrosarcoma protuberans (DFSP). DFSP can be a challenging disease to manage and adequate understanding of the most up to date literature can help provide comprehensive treatment strategies.

RECENT FINDINGS

DFSP is an infiltrative cutaneous sarcoma. It tends to have deep local invasion with a high risk of local recurrence, but a low risk of distant metastasis. It presents typically as a slow growing, asymptomatic skin lesion. It presents rarely in the head and neck, only 15% of the time. Recent data has discussed the role of wide local excision (WLE) vs. Mohs surgery. In addition, for unresectable disease the role of systemic therapy and immunomodulatory agents such as Imatinib has shown success.

SUMMARY

Typically, surgical management is the first line for DFSP, however the risk for local recurrence still remains high with negative margins. Due to this risk, lifelong surveillance is required after initial diagnosis and management. Similar to other head and neck tumors, most recurrences happen within the first 3 years after treatment. DFSP can be treated with WLE or Mohs. For aggressive disease that is considered unresectable systemic therapy does exist, including molecular targeted therapies.

Atrophic Pigmented Dermatofibrosarcoma Protuberans: A Case Report and Literature Review

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma characterized by the proliferation of spindle cells arranged in a storiform pattern. Here we report a case of DFSP presenting as a bluish-black atrophic plaque. The tumor had the histopathologic characteristics of both the pigmented and atrophic variants of DFSP. We describe the histopathologic, molecular, and imaging features of this patient and review other cases of DFSP that have been reported in the literature. Early identification of this DFSP variant can help clinicians implement clinical management strategies to prevent recurrence.

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.

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.

Comparing the Efficacy of Cancer Therapies between Subgroups in Basket Trials

The need to test anticancer drugs in multiple indications has been addressed by basket trials, which are Phase I or II clinical trials involving multiple tumor subtypes and a single master protocol. Basket trials typically involve few patients per type, making it challenging to rigorously compare responses across types. We describe the use of permutation testing to test for differences among subgroups using empirical null distributions and the Benjamini-Hochberg procedure to control for false discovery. We apply the approach retrospectively to tumor-volume changes and progression-free survival in published basket trials for neratinib, larotrectinib, pembrolizumab, and imatinib and uncover examples of therapeutic benefit missed by conventional binomial testing. For example, we identify an overlooked opportunity for use of neratinib in lung cancers carrying ERBB2 Exon 20 mutations. Permutation testing can be used to design basket trials but is more conservatively introduced alongside established approaches to enrollment such as Simon’s two-stage design.

Basket clinical trials simultaneously test a single drug in multiple tumor subtypes, but statistical challenges limit the comparison of responses across subtypes. We describe a rigorous approach to permutation testing using empirical null distributions that can identify previously overlooked opportunities for use of targeted therapy in genetically defined cancer subtypes.

Tyrosine Kinase Receptors in Oncology

Tyrosine kinase receptors (TKR) comprise more than 60 molecules that play an essential role in the molecular pathways, leading to cell survival and differentiation. Consequently, genetic alterations of TKRs may lead to tumorigenesis and, therefore, cancer development. The discovery and improvement of tyrosine kinase inhibitors (TKI) against TKRs have entailed an important step in the knowledge-expansion of tumor physiopathology as well as an improvement in the cancer treatment based on molecular alterations over many tumor types. The purpose of this review is to provide a comprehensive review of the different families of TKRs and their role in the expansion of tumor cells and how TKIs can stop these pathways to tumorigenesis, in combination or not with other therapies. The increasing growth of this landscape is driving us to strengthen the development of precision oncology with clinical trials based on molecular-based therapy over a histology-based one, with promising preliminary results.

NTRK and other recently described kinase fusion positive uterine sarcomas: A review of a group of rare neoplasms

The landscape of uterine sarcomas has greatly expanded in recent years to include neoplasms with recurrent gene fusions, such as BCOR and YWHAE translocated high-grade endometrial stromal sarcomas. Sophisticated molecular techniques have also resulted in the description of "new" entities associated with recurrent kinase fusions involving NTRK and RET as well as COL1A1-PDGFB rearranged uterine sarcomas. These rare neoplasms will be discussed in this review, highlighting that some of the underlying molecular events are clinically actionable and potentially susceptible to targeted therapy. While relatively few of these neoplasms have been described to date, likely being previously lumped under the spectrum of undifferentiated uterine sarcoma, the number of cases will expand in the future given their recognition and the increasing availability of molecular testing. These neoplasms have overlapping morphology (often with a "fibrosarcoma-like" appearance) and immunohistochemical features, and are characterized by variable clinical outcomes. Although immunohistochemistry may assist in some cases, a definitive subclassification requires confirmatory molecular studies. As these molecular assays may not be routinely available in most laboratories, referral to reference centers may be needed. In order to assist the pathologist, we suggest a diagnostic algorithm for routine practice when dealing with a malignant or potentially malignant uterine spindle cell neoplasm.

Upregulated GRB7 promotes proliferation and tumorigenesis of Bladder Cancer via Phospho-AKT Pathway

Growth factor receptor-bound protein 7 (GRB7) has been found closely related to the occurrence and development of various tumors, but its function in bladder cancer has not yet been elucidated. The study is aiming at investigating the expression and function of GRB7 in bladder cancer. The Cancer Genome Atlas (TCGA) database was selected to analyze mRNA levels of GRB7 in bladder cancer. RT-qPCR and Western blot were conducted to detect the expression of GRB7 in normal bladder epithelial cells, seven bladder cancer cell lines and eight pairs of malignant/nonmalignant bladder tissues. The role of GRB7 in tumor proliferation and tumorigenesis was explored by establishing stable cells, in vitro cell experiments and in vivo xenograft models. The molecular regulation mechanism of GRB7 in bladder cancer was investigated by treatment with AKT inhibitor. GRB7 mRNA was upregulated in bladder cancer samples compared with that in normal tissue samples. Overexpressing GRB7 significantly promoted the proliferation and tumorigenesis of bladder cancer. However, silencing GRB7 played the retarding part. GRB7 promoted G1/S transition by activating the AKT pathway. Our results indicate that GRB7 plays an important role in promoting proliferation and tumorigenesis of bladder cancer.