Treatment and survival differences across tumor sites in malignant peripheral nerve sheath tumors: a SEER database analysis and review of the literature

Malignant Peripheral Nerve Sheath Tumor, a Heterogeneous, Aggressive Cancer with Diverse Biomarkers and No Targeted Standard of Care: Review of the Literature and Ongoing Investigational Agents

BACKGROUND

Malignant peripheral sheath tumor (MPNST) is a rare, aggressive form of soft-tissue sarcoma that presents a unique set of diagnostic and treatment challenges and is associated with major unmet treatment medical needs.

OBJECTIVE

The chief aim of this review is to consider the epidemiology, histology, anatomic distribution, pathologic signaling pathways, diagnosis, and management of MPNST, with a focus on potential targeted therapies. A subordinate objective was to establish benchmarks for the antitumor activity of such treatments.

RESULTS

MPNST has an incidence of 1:100,000 in the general population and 1:3500 among patients with the inherited condition of neurofibromatosis-1. Spindle-cell sarcomas of neural-crest origin, MPNSTs are frequently situated in the extremities and pelvis/trunk, often at the confluence of large nerve roots and bundles. Highly copy-number aberrant and enriched in chromosome 8, MPNSTs have a complex molecular pathogenesis that likely involves the interplay of multiple signaling pathways, including Ras/AKT/mTOR/MAPK, EGFR, p53, PTEN, and PRC2, as well as factors in the tumor microenvironment. A combination of magnetic resonance imaging (MRI) and positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) enables comprehensive assessment of both morphology and metabolism, while MRI- and ultrasound-guided core needle biopsy can confirm histopathology. Although surgery with wide excisional margins is now the chief curative approach to localized disease, MPNST-specific survival has not improved in decades. For advanced and metastatic MPNST, radiation and chemotherapy (chiefly with anthracyclines plus ifosfamide) have somewhat promising but still largely uncertain treatment roles, chiefly in local control, downstaging, and palliation. No single druggable target has emerged, no objective responses have been observed with a number of targeted therapies (cumulative disease control rate in our review = 22.9-34.8%), and combinatorial approaches directed toward multiple signal transduction mechanisms are hallmarks of ongoing clinical trials.

CONCLUSIONS

Despite advances in our understanding of the genetics and molecular biology of MPNST, further research is warranted to: (1) unravel the complex pathogenesis of this condition; (2) improve diagnostic yield; (3) delineate the appropriate roles of chemotherapy and radiation; and (4) develop a targeted therapy (or combination of such treatments) that is well tolerated and prolongs survival.

Health-related quality of life in patients with peripheral nerve tumors: results from the German multicentric Peripheral Nerve Tumor Registry

Objective

Peripheral nerve tumors (PNTs) are rare diseases. So far, no multicenter data on diagnostics, the efficacy of treatment, long-term outcomes, and health-related quality of life (HRQoL) exist. The establishment of the Peripheral Nerve Tumor Registry (PNTR) in 2015 allows for the systematic analysis of patients with tumors associated with peripheral nerves. The present study aims to investigate the impact of PNT on an individual's HRQoL and the effect of surgery.

Methods

HRQoL was pre- and postoperatively assessed by the Euro-Qol-5D-5L (EQ-5D-5L) and Euro-Qol visual analog scale (EQ-VAS) survey in the retrospective and prospective study arm in three active participating study centers. An index was calculated based on the EQ-5D-5L for the quantification of health state (0: worst possible state of health, 1: best possible state of health). The EQ-VAS ranges from 0% (worst imaginable health status) to 100% (best possible health status). Patient characteristics (age, sex), as well as disease (histopathological entity) and treatment (pre- and postoperative symptoms, type of treatment)-specific data, were analyzed.

Results

Data from 171 patients from three high-volume centers were included, with schwannoma (70.8%, n = 121) and neurofibroma (15.8%, n = 27) being the most prevalent histopathological diagnoses. Both the median health index value (preoperative: 0.887, n = 167; postoperative: 0.910, n = 166) and the median EQ-VAS (preoperative: 75%, n = 167; postoperative: 85%, n = 166) of the entire cohort regarding all histopathological diagnosis improved significantly after surgical therapy (p < 0.001). Preoperatively, 12.3% (n = 21) reached the highest index score of 1.0 in EQ-5D-5L and 100% in the EQ-VAS score in 5.3% (n = 9) of all patients. Postoperatively, the highest index score of 1.0 and 100% in the EQ-VAS score increased significantly and were achieved in 33.3% (n = 57) and 11.1% (n = 19) of the patients, respectively (p < 0.001).

Conclusion

For the first time, our study presents multicenter data on life quality and the effect of surgery in primarily benign peripheral nerve tumors. Early surgery at a specialized center could improve neurological outcomes and, in conclusion, better QoL. In summary, surgical therapy significantly improved the entire cohort's QoL, VAS, and analgesia.

Delayed emergence from anesthesia caused by an intraoperative cerebral embolism of a malignant peripheral nerve sheath tumor in a neurofibromatosis type 1 patient: a case report

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas which commonly arise from neurofibromatosis type 1. Lung metastases of the tumors are well-known, but intraoperative cerebral tumor embolisms of MPNSTs have not been reported in literature.

CASE PRESENTATION

A 52-year-old female patient with neurofibromatosis type 1 underwent a right lung partial resection for lung tumors. She was extubated after adequate recovery of spontaneous breathing; however, she could not respond to verbal commands. In the intensive care unit, her neurological examination revealed conjugate eye deviation, right hemiparalysis, and aphasia. Magnetic resonance imaging revealed acute cerebral ischemia, so she underwent an endovascular thrombectomy. The histopathological diagnosis of emboli was a MPNST, which was identical with that of the resected lung tumor.

CONCLUSION

We report the first case of delayed emergence caused by a cerebral tumor embolism of MPNST during partial lung resection.

Results of surgical treatment of patients with malignant peripheral nerve sheath tumors: a retrospective and prospective study

Background. Peripheral nerve sheath malignancies (PNSM) are a rare and aggressive group of sarcomas that can occur sporadically, after radiation therapy, or related to neurofibromatosis type 1. Loss of function of NF1, TP53, and CDKN2A genes is thought to contribute to the progression of benign neurofibroma to PNSM and is a poor prognostic sign. The optimal management of patients with this disease is currently unresolved, and specific prognostic factors have not been established. Aim. To analyze the results of surgical treatment in patients with PNSM and establish prognostic factors of overall and recurrence-free survival rate. Materials and methods. The retrospective and prospective studies enrolled adult patients with histologically confirmed PNSM treated between 1998 and 2021 at the N.N. Blokhin National Medical Research Center for Oncology. Surgical intervention was performed on 61 patients, 38 (62%) females and 23 (38%) males. The most common PNSM localization was paravertebral (22 [36%] patients), followed by retroperitoneal (14 [23%] patients), and upper and lower extremities (13 [21%] and 12 [20%] patients, respectively). Results. For PNSM patients with a history of surgery, the median overall survival (OS) was 46 months (95% confidence interval 26.165.9). The 3-year and 5-year OS was 46% and 31%, respectively. The median recurrence-free survival (RFS) was 27 months (8.745.3), and 3-year and 5-year RFS was 26% and 13%, respectively. Median OS for grade 1 malignancies was not achieved, while grade 2 and grade 3 malignancy was 53 and 33 months, respectively (p=0.033). The median RFS for grade 1, 2, and 3 tumors was 119, 43, and 15 months, respectively (p=0.078). Patients who underwent radical (R0) surgery had higher RFS (p=0.006) and OS (p0.0001). After radical (R0) surgery, the median OS was not achieved; after nonradical (R1/R2) surgery, the median was 34 months. The median RFS was 124 months after R0-resection and 48 months after R1/R2. Conclusion. The most significant prognostic factors in PNSM patients are the radicality of the surgery performed and the malignancy grade. In our study, tumor size and localization did not affect the long-term treatment results.

The Role of Socioeconomic Status and Race/Ethnicity in Malignant Peripheral Nerve Sheath Tumor Survival: A Surveillance, Epidemiology, and End Results-Based Analysis

BACKGROUND

Recent investigations of malignant peripheral nerve sheath tumor (MPNST) survival have reported higher mortality among non-White individuals. However, previous analyses have not examined the impact of socioeconomic status (SES) on these observations. This study aims to characterize factors associated with cause-specific MPNST survival, including information related to census-tract-level SES (CT-SES).

METHODS

We identified 2,432 primary MPNSTs using the Surveillance, Epidemiology, and End Results (SEER) 18 (2000-2016) database. We used Cox proportional hazards modeling to estimate the effects of sex, race/ethnicity, CT-SES quintile, metastasis at diagnosis, tumor site, age at diagnosis, and treatment by surgery on survival. Models were fit in both the full population and, separately, stratified by race/ethnicity and age at diagnosis (&lt;40 vs. ≥40).

RESULTS

In adjusted models, age at diagnosis, CT-SES, and metastasis at diagnosis were associated with mortality. In race/ethnicity-stratified analysis, higher CT-SES was found to improve survival only in the White population. Among those diagnosed before age 40, metastasis at diagnosis and American Indian/Alaska Native race/ethnicity were associated with mortality, and both Hispanic ethnicity and Asian/Pacific Islander race were suggestive for increased mortality. Among cases, diagnoses at age 40 and above, age at diagnosis, male sex, and CT-SES were associated with mortality.

CONCLUSIONS

This analysis provides evidence that among pediatric and young adult patients, non-White populations experience inferior survival compared with Whites, independent of CT-SES. Our findings also suggest that the effect of CT-SES on MPNST survival may differ by racial/ethnic group.

IMPACT

These findings suggest that barriers to healthcare for certain racial/ethnic groups extend beyond SES.

Epidemiology, Characteristic, and Prognostic Factors of Primary Sporadic Intradural Malignant Peripheral Nerve Sheath Tumor in the Spinal Canal: A Systematic Literature Review

Purpose

Primary sporadic intradural malignant peripheral nerve sheath tumor (MPNST) in the spinal canal is a type of rare neoplasm with challenging diagnosis and therapy. The overall prognosis of this tumor is markedly different from that of the usual spinal intradural tumors. The purpose of this systematic review is to reduce the misdiagnosis and enhance the prognosis of the disease by reviewing the literature.

Methods

PubMed, Medline, and Embase databases were searched for articles in English language published from 1980 to May 2021, yielding 500 potentially relevant articles. The keywords were as follows: “spinal”, “malignant peripheral nerve sheath tumor”, “neurosarcoma”, “malignant schwannoma”, and “malignant neurofibroma”. Thirteen papers met the eligibility criteria, including 55 cases with spinal intradural primary sporadic MPNSTs, which were confirmed by post-operation pathology. We further analyzed the clinical manifestations, radiological manifestations, pathological features, comprehensive treatment strategies, and prognosis.

Results

Fifty-five spinal intradural primary sporadic MPNSTs from 30 (54.5%) male and 25 (45.5%) female patients with an average age at diagnosis of 40 years (range, 3–70 years) were included in the study. The most common clinical manifestations were local or radicular pain and motor disturbance. All tumors had significant enhancement and heterogeneous enhancement was more common. Out of 18 lesions, 14 were diagnosed as high grade and the remaining 4 were diagnosed as low grade. The ki-67 labeling index ranged from 5% to 60%. The median recurrence and survival time were 36 and 72 months, respectively. The log-rank tests indicated that significant predictors of OS were patient age (≤30 vs. >30 years) at the time of diagnosis and the presence of metastatic disease, and similar analyses for RFS demonstrated that the presence of metastatic disease was the only significant predictor (60 vs. 10 months). The multivariate Cox proportional hazards regression analysis revealed that absence of metastasis was an independent factor for predicting a favorable prognosis.

Conclusions

Spinal intradural primary sporadic MPNSTs are challenging malignant tumors without a systematic treatment plan. The factors affecting its prognosis are not clear. Even after surgical treatment and adjuvant treatment, the recurrence rate and mortality rate are still high. Clinicians should be alert to the possibility of this disease and achieve early detection and treatment.

Parotid Neurogenic Tumors: MPNST Sarcoma to Schwannoma-Review of Literature and Guidelines in Management

Objective

To delineate a distinct clinical, pathological, cytoimmunohistochemical distinguishing features of extracranial parotid neurogenic tumors. Pleomorphic adenoma, the most common parotid neoplasm by itself can mimic a neurogenic tumor, i.e., schwannoma. We have reported such rare entity in earlier publications. This is a systematic review with a case discussion of the third only documented malignant peripheral nerve sheath tumor (MPNST) arising in the parotid in a noncontiguous fashion. We review the management, diagnostic immunohistochemistry of this low-grade sarcoma, which has not been documented thus far.

Purpose

Significant diagnostic and management pitfalls may occur even with fine-needle aspiration or biopsy, as they will not be ideal in diagnosis of parotid neurogenic neoplasms preoperatively. Ultrasound as well as magnetic resonance imaging may not offer a specific facial nerve course in association to the neoplastic lesion. Majority of the neurogenic tumors can be misdiagnosed and hence, improperly managed leading to facial nerve injury and tumor morbidity. Due to the lack of ideal diagnostic modality and morbidity of facial nerve injury, a thorough review of differential diagnosis inclusive of neurogenic tumors of the parotid is to be considered in indications of surgical approaches. We retrospectively review successful resection with preservation of facial nerve function in our parotid neurogenic tumors.

Conclusion

The objective of this paper is to review the guidelines and treatment planning of parotid neurogenic tumors.

Malignant Peripheral Nerve Sheath Tumor of the Cerebellar Hemisphere: An Unusual Location and Multiple Intracranial Parenchyma Metastases

Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue malignancies that can occur in any part of the body. The most common sites are the proximal limbs and trunk. Intracranial MPNSTs are rare; most originate from the auditory, trigeminal, and other cranial nerves, and occurrence within the brain parenchyma is rarer. Here, we describe a malignant peripheral schwannoma in the cerebellar hemisphere of the brain parenchyma. To our knowledge, this is the first case of brain parenchymal metastasis of an MPNST. We observed no effects on the tumor after the application of multiple chemotherapy drugs; thereafter, we explored the literature surrounding the condition.

Prognostic Significance of Immunohistochemical Markers and Genetic Alterations in Malignant Peripheral Nerve Sheath Tumors: A Systematic Review

Background

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas with dismal prognosis. Pathological and genetic markers may predict more aggressive behavior in MPNSTs but have uncommonly been investigated, and few are used in daily practice. This study reviews the prognostic value of immunohistochemical markers and genetic alterations in MPNST.

Methods

A systematic search was performed in PubMed and Embase databases according to the PRISMA guidelines. Search terms related to ‘MPNST’ and ‘prognostic’ were used. Studies investigating the association of immunohistochemical markers or genetic alterations with prognosis were included. Qualitative synthesis was performed on all studies. A distinction was made between univariable and multivariable associations.

Results

Forty-six studies were included after full-text screening. Sixty-seven different immunohistochemical markers were investigated. Absence of S100 and H3K27me3 and high Ki67 and p53 staining was most commonly independently associated with worse survival and disease-free survival. Several genetic alterations were investigated as well with varying association to survival. TP53, CDK4, RASSF1A alterations were independently associated with worse survival, as well as changes in chromosomal length in Xp, 10q, and 16p.

Conclusions

MPNSTs harbor complex and heterogeneous biology. Immunohistochemical markers and genetic alterations have variable prognostic value. Absence of S100 and H3K27me3 and increased Ki67 can be of prognostic value. Alterations in TP53 or increase in p53 staining may distinguish MPNSTs with worse outcomes. Genetic alterations and staining of other cell cycle regulatory and Ras pathway proteins may also help stratifying patients with worse outcomes. A combination of markers can increase the prognostic value.

Histopathologic findings in malignant peripheral nerve sheath tumor predict response to radiotherapy and overall survival

Background

Malignant peripheral nerve sheath tumor (MPNST) is an aggressive and poorly understood malignant neoplasm. Even in the setting of multimodal therapy, the clinical course of MPNST is frequently marked by metastatic conversion and poor overall prognosis, with optimal treatment paradigms for this rare tumor unknown.

Methods

We reviewed the medical records and histopathology of 54 consecutive patients who were treated at University of California San Francisco between 1990 and 2018.

Results

Our cohort consisted of 24 male and 30 female patients (median age 38 years). Fédération Nationale des Centres de Lutte Contre Le Cancer (FNCLCC) sarcoma grading criteria segregated patients into groups with differences in overall survival (OS) (P = .02). Increasing Ki-67 labeling index was associated with poor OS (hazard ratio [HR] 1.36 per 10%, P = .0002). Unsupervised hierarchical clustering-based immunohistochemical staining patterns identified 2 subgroups of tumors with differences in H3K27me3, Neurofibromin, S100, SOX10, p16, and EGFR immunoreactivity. In our cohort, cluster status was associated with improved locoregional failure-free rate (P = .004) in response to radiation.

Conclusions

Our results lend support to the FNCLCC sarcoma grading criteria as a prognostic scheme for MPNST, although few cases of grade 1 were included. Further, we identify increased Ki-67 labeling as a strong predictor of poor OS from MPNST. Finally, we identify a subset of MPNSTs with a predictive immunohistochemical profile that has improved local control with adjuvant radiotherapy. These data provide insights into the grading and therapy for patients with MPNST, although further studies are needed for independent validation.

Neurofibromatosis-associated malignant peripheral nerve sheath tumors in children have a worse prognosis: A nationwide cohort study

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNST) are rare and aggressive non-rhabdomyoblastic soft-tissue sarcomas (NRSTS) in children. This study set out to investigate clinical presentation, treatment modalities, and factors associated with survival in pediatric MPNST using Dutch nationwide databases.

METHODS

Data were obtained from the Netherlands Cancer Registry (NCR) and the Dutch Pathology Database (PALGA) from 1989 to 2017. All primary MPNSTs were collected. Demographic differences were analyzed between adult and pediatric (age ≤18 years) MPNST. In children, demographic and treatment differences between neurofibromatosis type 1 (NF1) and non-NF1 were analyzed. A Cox proportional hazard model was constructed for localized pediatric MPNSTs.

RESULTS

A total of 70/784 MPNST patients were children (37.1% NF1). Children did not present differently from adults. In NF1 children, tumor size was more commonly large (> 5 cm, 92.3% vs 59.1%). Localized disease was primarily resected in 90.6%, and radiotherapy was administered in 37.5%. Non-NF1 children tended to receive chemotherapy more commonly (39.5% vs 26.9%). Overall, estimated five-year survival rates of localized NF1-MPNST was 52.4% (SE: 10.1%) compared with 75.8% (SE: 7.1%) in non-NF1 patients. The multivariate model showed worse survival in NF1 patients (HR: 2.98; 95% CI, 1.17-7.60, P = 0.02) and increased survival in patients diagnosed after 2005 (HR: 0.20; 95% CI, 0.06-0.69, P = 0.01). No treatment factors were independently associated with survival.

CONCLUSION

Pediatric MPNSTs have presentations similar to adult MPNSTs. In children, NF1 patients present with larger tumors, but are treated similarly to non-NF1 MPNSTs. In localized pediatric MPNST, NF1 is associated with worse survival. Promisingly, survival has increased for pediatric MPNSTs after 2005.

Oncological Treatment Considerations Differ across Surgical Subspecialties Treating Malignant Peripheral Nerve Sheath Tumors: An International Survey

Background

Malignant peripheral nerve sheath tumors (MPNSTs) are rare and aggressive soft tissue sarcomas (STS) that, because of their origin, are operated by several surgical subspecialties. This may cause differences in oncologic treatment recommendations based on presentation. This study investigated these differences both within and between subspecialties.

Methods

A survey was distributed among several (inter)national surgical societies. Differences within and between subspecialties were analyzed by χ²-tests.

Results

In total, 30 surgical oncologists, 30 neurosurgeons, 85 plastic surgeons, and 29 “others” filled out the survey. Annual caseload, tumor sites operated, and fellowship training differed significantly between subspecialties. While most surgeons agreed upon preoperative use of MRI, the use of radiological staging and FDG-PET use differed between subspecialties. Surgical oncologists agreed upon core needle biopsies as an ideal type of biopsy while other subspecialties differed in opinion. On average, 53% of surgeons always consider preservation of function preoperatively, but 42% would never perform less extensive resections for function preservation. Respondents agreed that radiotherapy should be considered in tumor sizes >10 cm, microscopic, and macroscopic positive margins. A preferred sequence of radiotherapy administration differed between subspecialties. There was no consensus on indications and sequence of administration of chemotherapy in localized disease.

Conclusion

Surgical oncologists generally agree on preoperative diagnostics; other subspecialties do not. Considering the preservation of function differed among all subspecialties. Surgeons do agree on some indications for radiotherapy, yet the use of chemotherapy in localized MPNSTs lacks consensus. A preferred sequence of multimodal therapy differs between and within surgical subspecialties, but surgical oncologists prefer neoadjuvant radiotherapy.

Treatment of malignant peripheral nerve sheath tumors in pediatric NF1 disease

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) are rare yet highly aggressive soft tissue sarcomas. Children with neurofibromatosis type 1 (NF1) have a 10% lifetime risk for development of MPNST. Prognosis remains poor and survival seems worse for NF1 patients.

METHODS

This narrative review highlights current practices and pitfalls in the management of MPNST in pediatric NF1 patients.

RESULTS

Preoperative diagnostics can be challenging, but PET scans have shown to be useful tools. More recently, functional MRI holds promise as well. Surgery remains the mainstay treatment for these patients, but careful planning is needed to minimize postoperative morbidity. Functional reconstructions can play a role in improving functional status. Radiotherapy can be administered to enhance local control in selected cases, but care should be taken to minimize radiation effects as well as reduce the risk of secondary malignancies. The exact role of chemotherapy has yet to be determined. Reports on the efficacy of chemotherapy vary as some report lower effects in NF1 populations. Promisingly, survival seems to ameliorate in the last few decades and response rates of chemotherapy may increase in NF1 populations when administering it as part of standard of care. However, in metastasized disease, response rates remain poor. New systemic therapies are therefore desperately warranted and multiple trials are currently investigating the role of drugs. Targeted drugs are nevertheless not yet included in first line treatment.

CONCLUSION

Both research and clinical efforts benefit from multidisciplinary approaches with international collaborations in this rare malignancy.