Salvage rates and prognostic factors after relapse in children and adolescents with malignant peripheral nerve sheath tumors

Contemporary surgical management of pediatric non-rhabdomyosarcoma soft tissue sarcoma

Non-rhabdomyosarcoma soft tissue sarcoma (STS) comprises most STS in pediatric patients. It is a diverse set of over 30 histologic subtypes. Treatment is based on risk group determined by tumor size, grade, and the presence of metastases. Surgical resection is a cornerstone of therapy, as tumors are often resistant to chemotherapy or radiation. While patients with isolated tumors less than 5 cm may undergo upfront resection, strong consideration should be given to neoadjuvant chemoradiotherapy to ensure negative margins at surgical resection and optimal outcomes. Sentinel lymph node biopsy is strongly recommended for clear cell and epithelioid sarcomas. The most common metastatic site is the lung, and metastases should be resected at the end of therapy, when feasible. Unfortunately, many high-risk patients progress on therapy, and alternative strategies including earlier metastatic control require investigation.

Local recurrence in malignant peripheral nerve sheath tumours: multicentre cohort study

BACKGROUND

Malignant peripheral nerve sheath tumours (MPNSTs) have high local recurrence (LR) rates. Literature varies on LR risk factors and treatment. This study aimed to elucidate treatment options and risk factors for first and second LRs (LR1 and LR2) in a large multicentre cohort.

METHOD

Surgically treated primary MPNSTs between 1988 and 2019 in the MONACO multicentre cohort were included. Cox regression analysed LR1 and LR2 risk factors and overall survival (OS) after LR1. Treatment of LR1 and LR2 was evaluated.

RESULTS

Among 507 patients, 28% developed LR1. Median follow-up was 66.9 months, and for survivors 111.1 months. Independent LR1 risk factors included high-grade tumours (HR 2.63; 95% c.i. 1.15 to 5.99), microscopically positive margins (HR 2.19; 95% c.i. 1.51 to 3.16) and large tumour size (HR 2.14; 95% c.i. 1.21 to 3.78). Perioperative radiotherapy (HR 0.62; 95% c.i. 0.43 to 0.89) reduced the risk. LR1 patients had poorer OS. Synchronous metastasis worsened OS (HR 1.79; 95% c.i. 1.02 to 3.14) post-LR1, while surgically treated LR was associated with better OS (HR 0.38; 95% c.i. 0.22 to 0.64) compared to non-surgical cases. Two-year survival after surgical treatment was 71% (95% c.i. 63 to 82%) versus 28% (95% c.i. 18 to 44%) for non-surgical LR1 patients. Most LR1 (75.4%) and LR2 (73.7%) patients received curative-intent treatment, often surgery alone (64.9% versus 47.4%). Radiotherapy combined with surgery was given to 11.3% of LR1 and 7.9% of LR2 patients.

CONCLUSION

Large, high-grade MPNSTs with R1 resections are at higher LR1 risk, potentially reduced by radiotherapy. Surgically treated recurrences may provide improved survival in highly selected cases.

Survival outcomes of malignant peripheral nerve sheath tumors (MPNSTs) with and without neurofibromatosis type I (NF1): a meta-analysis

INTRODUCTION

Malignant peripheral nerve sheath tumors (MPNSTs) are malignancies that demonstrate nerve sheath differentiation in the peripheral nervous system. They can occur sporadically or be associated with neurofibromatosis type 1 (NF1), an autosomal dominant neurocutaneous disorder, with up to 13% of patients developing MPNSTs in their lifetimes. Previous studies have suggested conflicting findings regarding the prognosis of NF1 for patients with MPNSTs. The elucidation of NF1 as an independent prognostic factor on mortality has implications for clinical management. We aim to investigate the role of NF1 status as an independent prognostic factor of overall survival (OS) and disease-specific survival (DSS) in MPNSTs.

METHODS

An electronic literature search of PubMed and MEDLINE was performed on studies reporting OS or DSS outcomes of MPNSTs with and without NF1. A grey literature search by reviewing bibliographies of included studies and review articles was performed to find pertinent studies. Data was extracted and assessed in accordance with the PRISMA guidelines. A meta-analysis was performed to calculate hazard ratios (HRs) using a random-effects model. The primary and secondary outcomes were all-cause and disease-specific mortality, respectively, with NF1 as an independent prognostic factor of interest.

RESULTS

A total of 59 retrospective studies involving 3602 patients fulfilled the inclusion criteria for OS analysis, and 23 studies involving 704 MPNST patients were included to evaluate DSS outcomes. There was a significant increase in the hazard of all-cause mortality (HR 1.63, 95% CI 1.45 to 1.84) and disease-specific mortality (HR 1.52, 95% CI 1.24 to 1.88) among NF1 as compared to sporadic cases. Subgroup analyses and meta-regression showed that this result was consistent regardless of the quality of the study and year of publication.

CONCLUSION

NF1 is associated with a substantially higher risk of all-cause and disease-specific mortality. This finding suggests that closer surveillance is required for NF1 patients at risk of developing MPNSTs.

Role of perioperative chemotherapy and radiotherapy for localized high-grade malignant peripheral nerve sheath tumor at the extremities and trunk wall: a population-based cohort study

BACKGROUND

Primary tumor resection is the mainstay of treatment for malignant peripheral nerve sheath tumors. However, the efficacy of perioperative chemotherapy and radiotherapy for malignant peripheral nerve sheath tumors has not been elucidated.

METHODS

This retrospective analysis based on a Japanese registry included patients with localized malignant peripheral nerve sheath tumors arising at the extremities and trunk wall. Disease-specific overall survival and local recurrence-free survival were estimated using the Kaplan-Meier method. A Cox regression model was used to identify prognostic factors. Characteristics of groups with or without chemotherapy were adjusted using propensity score matching.

RESULTS

In total, 291 patients were included. The 5-year disease-specific overall survival rate was 70.6%. Multivariate analysis of disease-specific overall survival revealed that deep-seated tumors were a poor prognostic factor, but perioperative chemotherapy was not associated with disease-specific overall survival (hazard ratio, 0.81; 95% confidence interval, 0.45-1.43, P = 0.46). Local recurrence was observed in 55 patients (19.0%), and surgical margins (R1 and R2) were significant risk factors. Overall, perioperative chemotherapy did not prolong disease-specific overall survival (5-year disease-specific overall survival: 74.1% vs. 69.3%, P = 0.75) and had limited efficacy in the group with tumor size ≥ 5 cm, although the difference was not statistically significant (5-year disease-specific overall survival: 77.2% vs. 68.6%, respectively, P = 0.13). After adjustment by propensity score matching, perioperative chemotherapy significantly prolonged disease-specific overall survival (5-year disease-specific overall survival: 74.9% vs. 57.1%, P = 0.03), but this effect was not observed in local recurrence-free survival. In all patients, perioperative radiotherapy did not correlate with local recurrence-free survival (hazard ratio, 1.43; 95% confidence interval 0.78-2.62, P = 0.25).

CONCLUSIONS

Perioperative chemotherapy had limited efficacy for disease-specific overall survival in patients with localized malignant peripheral nerve sheath tumors.

Analysis of treatment sequence and outcomes in patients with relapsed malignant peripheral nerve sheath tumors

Background

Malignant peripheral nerve sheath tumors (MPNST) are aggressive soft tissue sarcomas originating from cellular components within the nerve sheath. The incidence of MPNST is highest in people with neurofibromatosis type 1 (NF1), and MPNST is the leading cause of death for these individuals. Complete surgical resection is the only curative therapeutic option, but is often unfeasible due to tumor location, size, or presence of metastases. Evidence-based choices of chemotherapy for recurrent/refractory MPNST remain elusive. To address this gap, we conducted a retrospective analysis of our institutional experience in treating patients with relapsed MPNST in order to describe patient outcomes related to salvage regimens.

Methods

We conducted a retrospective electronic health record analysis of patients with MPNST who were treated at Johns Hopkins Hospital from January 2010 to June 2021. We calculated time to progression (TTP) based on salvage chemotherapy regimens.

Results

Sixty-five patients were included in the analysis. Upfront therapy included single or combined modalities of surgery, chemotherapy, or radiotherapy. Forty-eight patients received at least 1 line of chemotherapy, which included 23 different regimens (excluding active clinical studies). Most patients (n = 42, 87.5%) received a combination of doxorubicin, ifosfamide, or etoposide as first-line chemotherapy. Salvage chemotherapy regimens and their TTP varied greatly, with irinotecan/temozolomide-based regimens having the longest average TTP (255.5 days, among 4 patients).

Conclusions

Patients with advanced or metastatic MPNST often succumb to their disease despite multiple lines of therapy. These data may be used as comparative information in decision-making for future patients and clinical trials.

Soft tissue sarcoma in adolescent and young adult patients: a retrospective study using a nationwide bone and soft tissue tumor registry in Japan

OBJECTIVE

The relationship between the adolescent and young adult age groups and poor overall survival in soft tissue sarcoma and the risk factors for poor outcomes in adolescent and young adult patients with soft tissue sarcoma were analyzed.

METHODS

The medical records of 7759 Japanese patients diagnosed with soft tissue sarcoma from 2006-13 were accessed from the Bone and Soft Tissue Tumor registry. The epidemiological features of adolescent and young adult patients were compared with those of other age groups. The cancer survival rates were calculated using the Kaplan-Meier method. The prognostic factors for cancer survival were analyzed with the Cox proportional hazards models. The primary endpoint for prognosis was tumor-related death.

RESULTS

There were 210 children, 1467 adolescent and young adults, 2771 adults and 3311 elderly among the 7759 patients identified with soft tissue sarcoma. Compared with other age groups, the proportions of myxoid/round cell liposarcoma, synovial sarcoma, malignant peripheral nerve sheath tumor, primitive neuroectodermal tumor and rhabdomyosarcoma in adolescent and young adult patients were the highest, but none was significantly more prevalent in adolescent and young adult patients. On multivariate analysis, age was not a prognostic factor for poor cancer survival among adolescent and young adult patients with soft tissue sarcoma. The cancer survival rates of adolescent and young adult patients with malignant peripheral nerve sheath tumor were poorer than those of the other age groups; however, adolescent and young adult age was not a prognostic factor on multivariate analysis in malignant peripheral nerve sheath tumor patients.

CONCLUSIONS

Our study is the first to investigate soft tissue sarcoma in adolescent and young adult patients using the nationwide Bone and Soft Tissue Tumor registry. Adolescent and young adult age is not a prognostic factor for poor cancer survival among those with soft tissue sarcoma in Japan.

Efficacy of MEK inhibition in a recurrent malignant peripheral nerve sheath tumor

The prognosis of recurrent malignant peripheral nerve sheath tumors (MPNST) is dismal, with surgical resection being the only definitive salvage therapy. Treatment with chemoradiation approaches has not significantly improved patient outcomes. Similarly, trials of therapies targeting MPNST genomic drivers have thus far been unsuccessful. Improved understanding of the molecular pathogenesis of MPNST indicates frequent activation of the mitogen-activated protein kinase (MAPK) cell signaling pathway. MEK inhibitors have shown activity in preclinical studies; however, their clinical efficacy has not been reported to date. We describe here a case of sustained complete response to MEK inhibition in an adolescent patient with a recurrent metastatic MPNST with multiple alterations in the MAPK pathway, guided by a precision oncology approach.

Prognosis and risk factors for malignant peripheral nerve sheath tumor: a systematic review and meta-analysis

Background

No available meta-analysis was printed to systematically introduce the MPNST clinic outcome and risk factors based on largely pooled data. This systematic review and meta-analysis aimed to investigate 5-year OS rate, 5-year EFS rate, and LR rate for MPNST, and to assess potential risk factors for prognosis.

Methods

Electronic articles published between January 1, 1966 and February 29, 2020 were searched and critically evaluated. The authors independently reviewed the abstracts and extracted data for 5-year OS rate, 5-year EFS rate, LR rate, and potential risk factors for prognosis.

Results

Twenty-eight literatures were finally included for meta-analysis. The pooled 5-year OS rate, 5-year EFS rate, and LR rate were 49%, 37%, and 38%, respectively. The significant prognostic factors for survival were NF1 status, tumor size, depth, location, malignant grade, margin status, chemotherapy, and radiotherapy. Age and sex were not associated with survival.

Conclusion

Survival and local recurrence of MPNST are poor. Worse prognosis is mainly associated with NF 1, large size, deep to fascia, high grade, metastases, and location (trunk and head and neck). Complete resection with adequate surgical margins is the mainstay protective factor of MPNST patients, following necessary adjuvant therapies.

Malignant peripheral nerve sheath tumor of the bladder A case report

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon malignant tumor often associated with Neurofibromatosis type 1 (NF1). Although different soft tissue mesenchymal tumors may arise in the bladder, MPNST is a very rare occurrence. Here, we present a case of MPNST of the bladder in a 50 year old patient with NF1 with involvement of the entire wall of the organ leading to a functional exclusion. The principal differential diagnoses and a short review of the literature are presented.

Pediatric peripheral nerve tumors: clinical and surgical aspects

PURPOSE

Pediatric peripheral nerve tumors (PNTs) are rare. Most are related to neurofibromatosis type 1 (NF1) with the potential for malignancy. An ongoing debate occurs about the best approach to such patients. This study describes a cohort of pediatric patients with PNTs and discusses clinical characteristics and surgical treatment.

METHODS

We retrospectively reviewed the charts of seven pediatric patients with eight PNTs surgically treated from 2007 to 2018. Information concerning patient demographics, clinical presentation, PNTs characteristics, treatment choice, and outcome were recorded.

RESULTS

All children presented with intense pain and a palpable mass. Three of the eight tumors were associated with a neurological deficit. Among the four patients with NF1, two had a neurofibroma and two a malignant peripheral nerve sheath tumor (MPNST). Histologically, three of the lesions were a benign peripheral nerve sheath tumor (BPNST), three a MPNST, and one each a desmoid tumor and Ewing's sarcoma. Two of the eight tumors underwent partial tumor excision and six gross total excisions.

CONCLUSIONS

Intense pain at rest, day, and/or night, preventing normal activities; a palpable, hard, immobile mass; an intense Tinel's sign related to the lump; clinical evidence of NF1; and high-speed growth of a tumor in the trajectory of the nerve or plexus should alert the clinician to the potential for malignancy. Preoperative biopsy is not indicated when clinical and imaging findings suggest a benign tumor. The surgical management of PNTs must be to achieve total resection, including wide margins with malignant tumors, though this is not always possible.

Malignant triton tumor of trigeminal nerve-case report

INTRODUCTION

Here we are presenting a unique case of malignant triton tumor of the trigeminal nerve in a 4-year-old boy who presented with diplopia and ptosis.

INTERVENTION

Near total excision of the tumor was performed, and adjuvant chemotherapy and radiotherapy were administered.

RESULTS

The patient is in good health and has no evidence of clinical and radiological tumor recurrence for 22  months.