Long-term outcomes of surgical resection with or without adjuvant therapy for treatment of primary spinal peripheral primitive neuroectodermal tumors

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.

Cranial Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumors: A Retrospective Study Focused on Prognostic Factors and Long-Term Outcomes

Purpose: Cranial Ewing sarcoma (ES)/peripheral primitive neuroectodermal tumors (pPNETs) are rarely reported because of their extremely low incidence, and the current understanding of these tumors is poor. The purpose of this study was to illustrate the clinical, radiological, and pathological features of cranial ES/pPNETs and to discuss prognostic factors by survival analysis.

Methods: A total of 31 patients who were pathologically diagnosed with cranial ES/pPNETs between 2000 and 2019 were enrolled in this study. To identify which parameters were associated with higher progression-free survival (PFS) and overall survival (OS) rates, univariate and multivariate analyses were performed.

Results: The mean follow-up period was 24.8 months (range, 1–109 months). Eighteen (58.1%) patients had local recurrence and seven (22.6%) patients had distant metastasis. The results of the univariate analysis suggest that the extent of resection and adjuvant radiotherapy are potential prognostic factors for PFS and OS. Adjuvant chemotherapy was associated with OS (P = 0.027) but not with PFS (P = 0.053). The multivariate analysis revealed that the extent of resection and adjuvant radiotherapy were independent prognostic factors for both PFS and OS. In addition, metastasis was an adverse prognostic factor for OS.

Conclusions: Surgical management plays a crucial role in the treatment of cranial ES/pPNETs, and gross total resection should be striven for whenever possible. Post-operative radiotherapy is highly recommended to improve PFS and OS. This study also confirms that metastasis is an adverse prognostic factor for cranial ES/pPNETs.

Clinical presentation and long-term outcome of primary spinal intradural malignant peripheral nerve sheath tumors

OBJECTIVE

Primary spinal intradural malignant peripheral nerve sheath tumors (MPNSTs) are exceedingly rare, and there is limited published information regarding these lesions. The purpose of this study was to analyze the clinical course, treatment, and outcome of primary spinal intradural MPNSTs.

PATIENTS AND METHODS

A retrospective study was performed on 8 patients with primary spinal intradural MPNSTs who were surgically treated and pathologically confirmed in our institution between 2007 and 2018.

RESULTS

There were 3 females and 5 males, with a median age of 46.5 years (range, 21-68 years). Limb weakness was the most common clinical symptom (5/8, 62.5%). The radiological diagnosis was meningioma or schwannoma in most patients (7/8, 87.5%). Malignancies were graded high in 5 cases (62.5%) and low in 3 cases (37.5%). Gross total resection (GTR) was performed in 5 cases, while subtotal resection (STR) was achieved in 3 cases. The mean follow-up period was 48.9 months (range, 10-160 months). During follow-up, local recurrence occurred in 6/8 cases (75.0%) and distant metastasis occurred in 2/8 cases (25.0%). The median survival time (MST) of these 8 patients was 21.0 months. The overall 1-year, 2-year, and 5-year survival rates were 87.5% (7/8), 50.0% (4/8), and 25.0% (2/8), respectively.

CONCLUSIONS

Primary spinal intradural MPNST is a challenging clinical entity given its high local relapse rate. Primary spinal intradural MPNSTs radiologically present themselves heterogeneous and thus difficult to distinguish from schwannomas or meningiomas. Surgical resection, especially GTR, is the preferential treatment for primary spinal intradural MPNSTs.