Departments of1Neurosurgery.
2Oncology and Neurology.
Neurosurg Focus. 2023 Aug;55(2):E3. doi: 10.3171/2023.5.FOCUS23212.
Brain metastases (BMs) are the most common CNS tumors, yet their prevalence is difficult to determine. Most studies only report synchronous metastases, which make up a fraction of all BMs. The authors report the incidence and prognosis of patients with synchronous and metachronous BMs over a decade.
Study data were obtained from the TriNetX Research Network. Patients were included if they had a primary cancer diagnosis and a BM diagnosis, with primary cancer occurring between January 1, 2013, and January 1, 2023. Metachronous BM was defined as BM diagnosed more than 2 months after the primary cancer. Cohorts were balanced by propensity score matching for age, extracranial metastasis, and antineoplastic or radiation therapy. Kaplan-Meier plots were used to evaluate survival differences between synchronous and metachronous BMs and associations with clinical conditions. A log-rank test was used to evaluate BM-free survival for metachronous BM and overall survival (OS) for all BMs. Hazard ratios and 95% CIs were calculated.
Of the 11,497,663 patients with 15 primary cancers identified, 300,863 (2.6%) developed BMs. BMs most commonly arose from lung and breast cancers and melanoma. Of all BMs, 113,827 (37.8%) presented synchronously and 187,036 (62.2%) presented metachronously. Lung and bronchial cancer had the highest metastasis rate (11.0%) and the highest synchronous presentation (51.0%). For metachronous presentations, the time from primary diagnosis to metastasis ranged from 1.3 to 2.5 years, averaging 1.8 years. Metachronous BM diagnosis was associated with longer survival over synchronous BM from primary diagnosis (11.54 vs 37.41 months, p < 0.0001), but shorter survival than extracranial metastases without BM (38.75 vs 69.18 months, p < 0.0001). Antineoplastic therapy prior to BM was associated with improved BM-free survival (4.46 vs 17.80 months, p < 0.0001) and OS (25.15 vs 42.26 months, p < 0.0001). Radiotherapy showed a similar effect that was statistically significant but modest for BM-free survival (5.25 vs 11.44 months, p < 0.0001) and OS (30.13 vs 32.82 months, p < 0.0001).
The majority of BMs present metachronously and arise within 2 years of primary cancer diagnosis. The substantial rate of BMs presenting within 6 months of primary cancer, especially liver, lung, and pancreatic cancer, may guide future recommendations on intracranial staging. Antineoplastic therapy prior to the development of BM may prolong the time before metastasis and improve survival. Further characterization of this population can better inform screening, prevention, and treatment efforts.
脑转移瘤（BMs）是最常见的中枢神经系统肿瘤，但难以确定其患病率。大多数研究仅报告同步转移瘤，而同步转移瘤仅占所有 BMs 的一部分。作者报告了在十年间患有同步和异时性 BMs 的患者的发病率和预后。
研究数据来自于 TriNetX 研究网络。如果患者有原发性癌症诊断和 BMs 诊断，且原发性癌症发生在 2013 年 1 月 1 日至 2023 年 1 月 1 日之间，则纳入研究。异时性 BMs 定义为原发性癌症诊断后 2 个月以上发生的 BMs。通过年龄、颅外转移和抗肿瘤或放射治疗的倾向评分匹配来平衡队列。使用 Kaplan-Meier 图评估同步和异时性 BMs 之间的生存差异，并评估与临床状况的关联。对数秩检验用于评估异时性 BMs 的无 BMs 生存和所有 BMs 的总生存（OS）。计算了危险比和 95%置信区间。
在确定的 11497663 例 15 种原发性癌症患者中，有 300863 例（2.6%）发生了 BMs。BMs 最常源自肺癌、乳腺癌和黑色素瘤。在所有 BMs 中，113827 例（37.8%）为同步发生，187036 例（62.2%）为异时发生。肺癌和支气管癌的转移率最高（11.0%），同步发生的比例最高（51.0%）。对于异时性表现，从原发性诊断到转移的时间范围为 1.3 至 2.5 年，平均为 1.8 年。与同步性 BMs 相比，从原发性诊断到异时性 BMs 的诊断后的生存时间更长（11.54 个月与 37.41 个月，p < 0.0001），但比无 BMs 的颅外转移短（38.75 个月与 69.18 个月，p < 0.0001）。BM 发生前的抗肿瘤治疗与 BM 无进展生存（4.46 个月与 17.80 个月，p < 0.0001）和 OS（25.15 个月与 42.26 个月，p < 0.0001）的改善相关。放疗对 BM 无进展生存（5.25 个月与 11.44 个月，p < 0.0001）和 OS（30.13 个月与 32.82 个月，p < 0.0001）的影响相似，但统计学上有显著意义，但幅度较小。
大多数 BMs 呈异时性表现，发生在原发性癌症诊断后 2 年内。原发性癌症后 6 个月内发生 BMs 的比例相当高，尤其是肝癌、肺癌和胰腺癌，这可能会指导未来对颅内分期的建议。BM 发生前的抗肿瘤治疗可能会延长转移前的时间并改善生存。对该人群的进一步特征描述可以更好地为筛查、预防和治疗工作提供信息。
