Geng Ruixuan, Zheng Zhibo, Lin Yuxiao, Li Yaguang, Ge Guannan, Zhang Jieshi, Wang Chenyu, Dai Xiaoyan, Ye Qiuyue, Zhen Junfeng, Zhang Ying, Fu Chenwei, Li Yongning
Department of International Medical Services, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, China.
Department of Thoracic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
World J Urol. 2021 Apr;39(4):1211-1217. doi: 10.1007/s00345-020-03311-y. Epub 2020 Jun 19.
Yolk sac tumor (YST) is a rare malignant germ cell tumor, which usually affects young males. Because of the low incidence, few studies on YST have been published. In our study, we aim to investigate the clinical characteristics, survival and risk factors of male YST patients based on the Surveillance, Epidemiology, and End Results (SEER) program.
We identified 569 male YST patients from the SEER-18 database with additional treatment fields. Clinical characteristics, survival and prognostic factors were described in the study. Chi-square tests were applied to analyze categorical and continuous variables between different groups. Univariate and multivariate Cox proportional hazard model were performed to assess the relative impacts of risk factors on cancer-specific survival (CSS) in YST patients. Kaplan-Meier method and the log-rank test were used to analyze differences in survival that were significant.
The major primary sites of YST were testis (74.69%), mediastinum (15.47%), retroperitoneum (2.64%) and central nervous system (1.24%). The 3-year and 5-year CSS was 70.0%, 56.5% vs. 97.2%, 96.0% for the mediastinal and testicular YST patients, respectively (p < 0.001). Primary site of mediastinum, distant SEER Summary stage were independent factors of poor prognosis (hazard ratio (HR) = 2.010 (1.094-3.695), p = 0.025; HR = 6.501 (2.294-18.424), p < 0.001, respectively). Receiving surgery was a good prognosis factor for all patients (HR = 0.495 (0.260-0.940), p = 0.032) and for the mediastinal group (p = 0.0019). Being treated with chemotherapy indicated poor outcome in all patients (HR = 3.624 (1.050-12.507), p = 0.042) and in the localized testicular YST patients (p = 0.0077).
For the first time, our study revealed the primary site distribution of male YST, and summarized the clinical characteristics, survival and prognostic factors based on the SEER database, which provided important epidemiological evidence for clinical practice.
卵黄囊瘤（YST）是一种罕见的恶性生殖细胞肿瘤，通常影响年轻男性。由于发病率低，关于YST的研究报道较少。在本研究中，我们旨在基于监测、流行病学和最终结果（SEER）计划，调查男性YST患者的临床特征、生存率及危险因素。
我们从SEER - 18数据库中确定了569例有额外治疗区域的男性YST患者。本研究描述了其临床特征、生存率及预后因素。采用卡方检验分析不同组间的分类变量和连续变量。运用单因素和多因素Cox比例风险模型评估危险因素对YST患者癌症特异性生存（CSS）的相对影响。采用Kaplan - Meier法和对数秩检验分析生存率的显著差异。
YST的主要原发部位为睾丸（74.69%）、纵隔（15.47%）、腹膜后（2.64%）和中枢神经系统（1.24%）。纵隔和睾丸YST患者的3年和5年CSS分别为70.0%、56.5%和97.2%、96.0%（p < 0.001）。纵隔原发部位、远处SEER总结分期是预后不良的独立因素（风险比（HR）= 2.010（1.094 - 3.695），p = 0.025；HR = 6.501（2.294 - 18.424），p < 0.001）。接受手术对所有患者（HR = 0.495（0.260 - 0.940），p = 0.032）及纵隔组患者（p = 0.0019）而言是一个良好的预后因素。接受化疗对所有患者（HR = 3.624（1.050 - 12.507），p = 0.042）及局限性睾丸YST患者（p = 0.0077）而言提示预后不良。
我们的研究首次揭示了男性YST的原发部位分布，并基于SEER数据库总结了其临床特征、生存率及预后因素，为临床实践提供了重要的流行病学证据。
