Li Jiuhong, Wang Qiguang, Zhang Menglan, Zhang Guisheng, Zhang Si, Hui Xuhui
Department of Neurosurgery of West China Hospital, Sichuan University, Chengdu, China.
West China School of Medicine, West China Hospital, Sichuan University, Chengdu, China.
Front Oncol. 2021 Apr 14;11:655260. doi: 10.3389/fonc.2021.655260. eCollection 2021.
Vestibular schwannomas (VSs) are generally considered benign tumors, and malignant transformation of VSs (MTVSs) are rare findings. The clinical features, treatment strategy, outcomes and prognostic factors remain unclear. We endeavored to analyze the natural history, management, outcomes and prognostic factors of MTVSs.
The clinical features, radiologic findings, pathological investigations and surgical outcomes of 4 patients with MTVSs treated at the authors' institution between 2010 and 2019 were retrospectively collected. Related literature published until December 2019 (63 articles, 67 patients) was evaluated. The authors also made a pooled analysis to evaluate the risk factors for overall survival (OS) time.
Of the 4 cases in our series, 3 cases were malignant transformation following previous treatment (surgery and radiosurgery) and 1 was primary MTVS. Of the 71 MTVSs from the literature, 27 were male and 39 were female, with the mean age of 47.2 ± 17.5 years old. Twelve patients (18.5%) were diagnosed with NF2 (15.4%) or NF1 (3.1%). Forty-three (61.4%) patients underwent previous treatment (surgery and/or radiotherapy) prior to the pathological diagnosis of MTVSs. The mean size of the MTVSs was 35.1 ± 13.2mm. The mean Ki-67 index was 30.6% ± 18.8%. Twenty-four (49.0%) patients underwent gross total resection, 25 (51.0%) patients underwent incomplete resection. Twenty-five (44.6%) underwent adjuvant radiotherapy (RT) postoperatively. During the average follow-up of 9.9 ± 9.5 months (range, 0-40 months), 37 (82.2%) patients developed a local recurrence or metastasis. Forty-seven (73.4%) patients died of tumor progression or postoperative complications. The overall 1-year and 2-year survival rate was 42.3% and 18.6% respectively. Log-rank testing for Kaplan-Meier survival analysis identified that size (P = 0.047) and adjuvant radiotherapy (P=0.001) were significant prognostic factors for OS. Multivariate analysis revealed that adjuvant RT was the only prognostic factor for longer OS (P = 0.005).
MTVSs are rare, fatal disease, prone to recur and metastasize rapidly, resulting in death in most of the cases. We found that GTR did not improve the survival in MTVSs but postoperative adjuvant RT can significantly improve the OS, and we recommend early postoperative RT in MTVSs regardless of extent of resection.
前庭神经鞘瘤（VSs）通常被认为是良性肿瘤，而VSs的恶性转化（MTVSs）则较为罕见。其临床特征、治疗策略、治疗结果及预后因素仍不明确。我们致力于分析MTVSs的自然病史、治疗方法、治疗结果及预后因素。
回顾性收集了2010年至2019年间在作者所在机构接受治疗的4例MTVSs患者的临床特征、影像学表现、病理检查及手术结果。对截至2019年12月发表的相关文献（63篇文章，67例患者）进行了评估。作者还进行了汇总分析以评估总生存（OS）时间的危险因素。
在我们的系列4例病例中，3例是在先前治疗（手术和放射外科）后发生的恶性转化，1例是原发性MTVS。在文献中的71例MTVSs中，男性27例，女性39例，平均年龄为47.2±17.5岁。12例患者（18.5%）被诊断为NF2（15.4%）或NF1（3.1%）。43例（61.4%）患者在MTVSs病理诊断之前接受过先前治疗（手术和/或放疗）。MTVSs的平均大小为35.1±13.2mm。平均Ki-67指数为30.6%±18.8%。24例（49.0%）患者接受了全切除，25例（51.0%）患者接受了不完全切除。25例（44.6%）患者术后接受了辅助放疗（RT）。在平均9.9±9.5个月（范围0 - 40个月）的随访期间，37例（82.2%）患者出现局部复发或转移。47例（73.4%）患者死于肿瘤进展或术后并发症。总体1年和2年生存率分别为42.3%和18.6%。Kaplan-Meier生存分析的对数秩检验确定肿瘤大小（P = 0.047）和辅助放疗（P = 0.001）是OS的重要预后因素。多因素分析显示辅助放疗是OS延长的唯一预后因素（P = 0.005）。
MTVSs是罕见的致命疾病，易于复发且迅速转移，大多数病例会导致死亡。我们发现全切除并不能提高MTVSs的生存率，但术后辅助放疗可显著提高OS，并且我们建议无论切除范围如何，MTVSs术后均应尽早进行放疗。
