The Role of ER Stress-Related Phenomena in the Biology of Malignant Peripheral Nerve Sheath Tumors.

Malignant peripheral nerve sheath tumors (MPNST) are rare but one of the most aggressive types of cancer. Currently, there are no effective chemotherapy strategies for these malignancies. The inactivation of the neurofibromatosis type I (NF1) gene, followed by loss of TP53, is an early stage in MPNST carcinogenesis. NF1 is a negative regulator of the Ras proteins family, which are key factors in regulating cell growth, homeostasis and survival. Cell cycle dysregulation induces a stress phenotype, such as proteotoxic stress, metabolic stress, and oxidative stress, which should result in cell death. However, in the case of neoplastic cells, we observe not only the avoidance of apoptosis, but also the impact of stress factors on the treatment effectiveness. This review focuses on the pathomechanisms underlying MPNST cells physiology, and discusses the possible ways to develop a successful treatment based on the molecular background of the disease.

Circulating tumor DNA for malignant peripheral nerve sheath tumors in neurofibromatosis type 1.

PURPOSE: The leading cause of early death in patients with neurofibromatosis type 1 (NF1) is malignant peripheral nerve sheath tumor (MPNST). The principles of management include early diagnosis, surgical clearance and close monitoring for tumor recurrence. Current methods for diagnosis, detection of residual disease and monitoring tumor burden are inadequate, as clinical and radiological features are non-specific for malignancy in patients with multiple tumors and lack the sensitivity to identify early evidence of malignant transformation or tumor recurrence. Circulating tumor DNA (ctDNA) is a promising tool in cancer management and has the potential to improve the care of patients with NF1. In the following article we summarise the current understanding of the genomic landscape of MPNST, report on the previous literature of ctDNA in MPNST and outline the potential clinical applications for ctDNA in NF1 associated MPNST. Finally, we describe our prospective cohort study protocol investigating the utility of using ctDNA as an early diagnostic tool for MPNSTs in NF1 patients.

Chromosomal translocations inactivating CDKN2A support a single path for malignant peripheral nerve sheath tumor initiation.

Malignant peripheral nerve sheath tumors (MPNST) are aggressive soft tissue sarcomas with poor prognosis, developing either sporadically or in persons with neurofibromatosis type 1 (NF1). Loss of CDKN2A/B is an important early event in MPNST progression. However, many reported MPNSTs exhibit partial or no inactivation of CDKN2A/B, raising the question of whether there is more than one molecular path for MPNST initiation. We present here a comprehensive genomic analysis of MPNST cell lines and tumors to explore in depth the status of CDKN2A. After accounting for CDKN2A deletions and point mutations, we uncovered a previously unnoticed high frequency of chromosomal translocations involving CDKN2A in both MPNST cell lines and primary tumors. Most identified translocation breakpoints were validated by PCR amplification and Sanger sequencing. Many breakpoints clustered in an intronic 500 bp hotspot region adjacent to CDKN2A exon 2. We demonstrate the bi-allelic inactivation of CDKN2A in all tumors (n = 15) and cell lines (n = 8) analyzed, supporting a single molecular path for MPNST initiation in both sporadic and NF1-related MPNSTs. This general CDKN2A inactivation in MPNSTs has implications for MPNST diagnostics and treatment. Our findings might be relevant for other tumor types with high frequencies of CDKN2A inactivation.

Personal and Familial Malignancy History in Patients with Malignant Peripheral Nerve Sheath Tumors with a Focus on Sporadic Tumors.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) occur sporadically, in patients with neurofibromatosis 1, and in patients with prior radiation therapy. The incidence of unrelated prior malignancies and family history of malignancy in patients with MPNSTs has not been previously described. METHODS: A retrospective search for cases of MPNSTs at our institution for the years 1994-2019 was performed. The electronic medical record was reviewed for documentation of personal and family history of malignancies. RESULTS: The study included 331 patients. Of patients, 301 had documentation of their personal history of prior unrelated malignancies; 70 (23.3%) of these patients had a personal history of an unrelated previous malignancy. Of patients, 285 had information in the chart regarding family history of cancer; 210 (73.7%) of these patients had a family history of malignancy. Of patients, 145 had sporadic MPNSTs, 118 had neurofibromatosis 1-associated MPNSTs, 31 had radiation-induced MPNSTs, and 37 were missing this information. Among the sporadic cases, 29 had a personal history of an unrelated prior malignancy, and 10 developed an unrelated malignancy following diagnosis of MPNST. A family history of malignancy was present in 109 patients. There was a trend toward longer time to recurrence, time to metastasis, and overall survival in patients with sporadic MPNSTs and negative personal and family histories compared with patients with positive personal or family histories or both. CONCLUSIONS: Patients with sporadic MPNSTs had a high incidence of personal and family history of malignancy. The genetics associated with sporadic MPNSTs include RAS and p53 mutations, which are found in multiple oncologic processes and tumor-forming syndromes. This suggests an underlying genetic predisposition to formation of malignancies, including MPNSTs.

Sarcoma neurogénico de la mama masculina. Presentación de un caso / Male breast neurogenic sarcoma. A case

RESUMEN El cáncer de mama en el sexo masculino es una entidad clínica poco frecuente, tiene una presentación unimodal a los 71 años de edad, generalmente se presenta de manera similar a la forma en que se presenta en el sexo femenino. Su causa es poco conocida. Los sarcomas son tumores de componentes mesenquimatoso que constituyen del 0,2-1 % de todos los tumores de mama, y menos del 5 % del total. El sarcoma neurogénico, a su vez, es un tumor extremadamente raro. Representa del 1-2 % aproximadamente, de los tumores de los nervios periféricos con transformación maligna. Debido a la rareza geográfica e histopatológica de este tipo y mucho más en pacientes masculinos se presentó este caso. Paciente masculino de 57 años de edad, con el diagnóstico de un sarcoma de la mama derecha. Se le realizó una mastectomía radical más quimioterapia y radioterapia adyuvante. Los estudios de inmunohistoquímicos permitieron llegar al diagnóstico de sarcoma neurogénico.

ABSTRACT Breast cancer in men (BCM) is a rare clinical entity that has a unimodal presentation at the age of 71 years, and generally presents in a similar way it presents in the female sex. Its etiology remains almost unknown. Sarcomas are tumors of mesenchymal components representing from 0.2 to 1 % of all the breast tumors and less than 5 % of the total. The neurogenic sarcoma is also an extremely rare tumor. It represents around 1-2 % of the peripheral nerves tumors with malignant transformations. Due to location and histopathological rarity of this kind of tumors, much more in male patients, the authors presented the case of a male patient, aged 57 years, with the diagnosis of a left breast sarcoma. He undergone a radical mastectomy plus adjuvant chemotherapy and radiotherapy. The immunohystochemical studies allowed arriving to the diagnosis of neurogenic sarcoma.

Comments on the US National Toxicology Program technical reports on toxicology and carcinogenesis study in rats exposed to whole-body radiofrequency radiation at 900 MHz and in mice exposed to whole-body radiofrequency radiation at 1,900 MHz.

During the use of handheld mobile and cordless phones, the brain is the main target of radiofrequency (RF) radiation. An increased risk of developing glioma and acoustic neuroma has been found in human epidemiological studies. Primarily based on these findings, the International Agency for Research on Cancer (IARC) at the World Health Organization (WHO) classified in May, 2011 RF radiation at the frequency range of 30 kHz­300 GHz as a 'possible' human carcinogen, Group 2B. A carcinogenic potential for RF radiation in animal studies was already published in 1982. This has been confirmed over the years, more recently in the Ramazzini Institute rat study. An increased incidence of glioma in the brain and malignant schwannoma in the heart was found in the US National Toxicology Program (NTP) study on rats and mice. The NTP final report is to be published; however, the extended reports are published on the internet for evaluation and are reviewed herein in more detail in relation to human epidemiological studies. Thus, the main aim of this study was to compare earlier human epidemiological studies with NTP findings, including a short review of animal studies. We conclude that there is clear evidence that RF radiation is a human carcinogen, causing glioma and vestibular schwannoma (acoustic neuroma). There is some evidence of an increased risk of developing thyroid cancer, and clear evidence that RF radiation is a multi­site carcinogen. Based on the Preamble to the IARC Monographs, RF radiation should be classified as carcinogenic to humans, Group 1.

Differentiation of peripheral nerve sheath tumors in patients with neurofibromatosis type 1 using diffusion-weighted magnetic resonance imaging.

BACKGROUND: We sought to determine the value of diffusion-weighted (DW) magnetic resonance imaging (MRI) for characterization of benign and malignant peripheral nerve sheath tumors (PNSTs) in patients with neurofibromatosis type 1 (NF1). METHODS: Twenty-six patients with NF1 and suspicion of malignant transformation of PNSTs were prospectively enrolled and underwent DW MRI at 3T. For a set of benign (n = 55) and malignant (n = 12) PNSTs, functional MRI parameters were derived from both biexponential intravoxel incoherent motion (diffusion coefficient D and perfusion fraction f) and monoexponential data analysis (apparent diffusion coefficients [ADCs]). A panel of morphological MRI features was evaluated using T1- and T2-weighted imaging. Mann-Whitney U-test, Fisher's exact test, and receiver operating characteristic (ROC) analyses were applied to assess the diagnostic accuracy of quantitative and qualitative MRI. Cohen's kappa was used to determine interrater reliability. RESULTS: Malignant PNSTs demonstrated significantly lower diffusivity (P < 0.0001) compared with benign PNSTs. The perfusion fraction f was significantly higher in malignant PNSTs (P < 0.001). In ROC analysis, functional MRI parameters showed high diagnostic accuracy for differentiation of PNSTs (eg, ADCmean, 92% sensitivity with 98% specificity, AUC 0.98; Dmean, 92% sensitivity with 98% specificity, AUC 0.98). By contrast, morphological imaging features had only limited sensitivity (18-94%) and specificity (18-82%) for identification of malignancy. Interrater reliability was higher for monoexponential data analysis. CONCLUSION: DW imaging shows better diagnostic performance than morphological features and allows accurate differentiation of benign and malignant peripheral nerve sheath tumors in NF1.

The characteristics of 76 atypical neurofibromas as precursors to neurofibromatosis 1 associated malignant peripheral nerve sheath tumors.

Background: Neurofibromatosis 1 (NF1) leads to the development of benign and malignant peripheral nerve sheath tumors (MPNST). MPNST have been described to develop in preexisting benign plexiform neurofibromas (PN) and have a poor prognosis. Atypical neurofibromas (ANF) were recently described as precursor lesions for MPNST, making early detection and management of ANF a possible strategy to prevent MPNST. We aimed to clinically characterize ANF and identify management approaches. Methods: We analyzed clinical, imaging, and pathology findings of all patients with NF1 and ANF at 3 institutions. Results: Sixty-three patients had 76 ANF (32M/31F; median age 27.1 y). On MRI, most ANF appeared as distinct nodular lesions and were 18F-fluorodeoxyglucose (FDG) avid. Forty-six ANF were associated with pain, 19 with motor weakness, 45 were palpable or visible, and 13 had no clinical signs. Completely resected ANF (N = 57) have not recurred (median follow-up, 4.1 y; range, 0-14 y). Four ANF transformed into MPNST and 17 patients had a history of MPNST in a different location than was their ANF. Conclusions: Growth of distinct nodular lesions, pain, and FDG-PET avidity should raise concern for ANF in NF1. Patients with ANF are at greater risk for development of MPNST. Complete resection of ANF may prevent development of MPNST.

Patterns of recurrence and survival in sporadic, neurofibromatosis Type 1-associated, and radiation-associated malignant peripheral nerve sheath tumors.

OBJECTIVE Malignant peripheral nerve sheath tumors (MPNSTs) are an aggressive group of soft tissue sarcomas that can arise sporadically, in the context of neurofibromatosis Type 1 (NF1) or at a site of prior irradiation. Large series profiling the features and outcomes of sporadic, NF1-associated, and radiation-associated MPNSTs are limited. The goal of this study was to elucidate differences between MPNST etiologies in a large single-institution retrospective study. METHODS Patients (n = 317) were identified through the tumor registry of The University of Texas MD Anderson Cancer Center. Clinicopathological features were retrospectively collected. Features were compared among MPNST subtypes for patients who had sufficient clinical history (n = 289), and clinicopathological features were used to identify adverse predictors of recurrence and survival outcomes. RESULTS Five-year local recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), and disease-specific survival (DSS) estimates were 56.6%, 49.6%, and 53.6%, respectively, for the high-grade MPNST cohort. Five-year DSS was lower in NF1-associated and radiation-associated MPNST than in sporadic MPNST (52%, 47%, and 67%, respectively, p = 0.140). Patients with radiation-associated MPNST had worse 5-year LRFS than those with the sporadic and NF1-associated subtypes (RT-associated vs sporadic, p = 0.010; RT-associated vs NF1-associated, p = 0.232). Truncally located tumors, positive surgical margins, local recurrence, and metastasis were predictors of adverse DSS in multivariate analysis. CONCLUSIONS Radiation-associated MPNSTs are associated with poorer local recurrence-free and disease-specific survival than sporadic and NF1-associated tumors. NF1-associated MPNSTs may have worse survival outcomes owing to large tumor size, compromising truncal location, and lower rate of negative resection margins compared with sporadic tumors.

[Malignant tumors of the peripheral nerve sheath (MPNST) after irradiation]. / Tumore maligno della guaina dei nervi periferici (MPNST) post-irradiazione.

A case of relapsed malignant tumor of the brachial plexus and its nervous roots (MPNST) was observed in a patient treated with radiotherapy for Hodgkin's disease 24 years previously. A known risk of radiation therapy is the induction of secondary neoplasms, less commonly malignant peripheral nerve sheath tumor (MPNST). The clinico-pathological features of this rare tumor are presented and the possible relationship between radiotherapy and MPNST is discussed.

Malignant change in cutaneous neurofibromas--case reports.

Neurofibromatosis is the most common single gene disorder to affect the nervous system, with an estimated incidence of 1 in 3000 live births. Neurofibromatosis (NF) may be classified into von Recklinghausen NF (NFI) and bilateral acoustic NF (NFII) based on the distribution of lesions. The most common lesion associated with the von Recklinghausen type is the neurofibroma. Various complications are associated with neurofibromatosis, the most feared of which is malignant change in the neurofibroma. This article describes the study of 7 cases of proven malignant change in neurofibromas with regards to presentation, clinical progress and treatment followed by a review of the present literature.

Subcutaneous sarcomas of probable neuronal origin in a transgenic mouse strain containing an albumin promoter-fused simian virus 40 large T antigen gene.

Frequent development of subcutaneous neurogenic sarcomas was observed in a hepatocellular carcinoma-producing transgenic mouse strain harboring an albumin-promoted simian virus 40 (SV40) large T antigen gene. Found unexpectedly in 19 out of 306 mice (6.2%) by 6 months of age, all the sarcomas were similar and were characterized as neurogenic on the basis of histological features including Homer-Wright type rosette formation, the presence of dense core granules of 100-200 nm diameter under the electron microscope, expression of neuron specific enolase, S-100 protein, and catecholamines, and nerve cell-like differentiation in culture in response to But2cAMP. Immunohistochemical study revealed tiny clusters of SV40 T antigen-expressing cells with neurogenic character in normal-appearing adult mouse subcutis as candidate progenitors of the sarcomas. The tumor cells strongly expressed large T antigen but did not express albumin or albumin mRNA at the detection sensitivity used. Transient transfection assay (CAT assay), however, revealed the presence of transcriptional factor(s) acting on the albumin promoter in tumor cells. Thus, the present investigation suggested the presence of specifically differentiated neurogenic cells in the mouse subcutis with aberrant expression of the transgene.