Department of Respiratory Medicine, Kanagawa Prefectural Cardiovascular and Respiratory Center, Yokohama, Japan.
Lung Cancer. 2012 Jul;77(1):64-9. doi: 10.1016/j.lungcan.2011.12.017. Epub 2012 Feb 13.
Miliary brain metastasis is a rarity and refers to the presence of numerous small tumors in a perivascular distribution without intraparenchymal invasion and focal edema. Although the presence of epidermal growth factor receptor (EGFR) mutation and good response to gefitinib have been reported in non-small cell lung cancer (NSCLC) patients with miliary brain metastases, the influence of the EGFR mutations on the radiographic features remains unclear.
All NSCLC patients with synchronous brain metastases detected at the time of a new diagnosis of NSCLC from March 2005 through May 2011 were divided according to EGFR mutation status. The number of brain tumors, size of the largest brain tumors, and size of peritumoral brain edema were compared among the groups.
Fifty-seven patients who met the criteria were divided into three groups: wild-type EGFR group (31 patients), exon 19 deletion group (18 patients), and exon 21 point mutation group (8 patients). The exon 19 deletion group had more multiple and smaller brain tumors with smaller peritumoral brain edema than did the wild-type group (P = 0.024, P = 0.0016, and P = 0.0036, respectively). The exon 21 point mutation group showed no significant difference in any of the radiographic values when compared with the wild-type group.
Our results indicate that NSCLC patients with the exon 19 deletion have such a peculiar pattern of brain metastases as multiple small metastases with small brain edema. This metastatic pattern may be similar to that of miliary brain metastases. Because it is unclear whether or not severe neurologic symptoms develop during their clinical courses like miliary brain metastases, regular evaluation with brain magnetic resonance imaging (MRI) should be considered, regardless of the presence of neurologic symptoms. Accumulation of knowledge about specific pattern of brain metastasis will help approach to "individual" management.
脑多发性转移是一种罕见的疾病，指的是在血管周围分布存在许多小肿瘤，没有脑实质侵犯和局灶性水肿。虽然已经报道在非小细胞肺癌（NSCLC）伴有脑多发性转移的患者中存在表皮生长因子受体（EGFR）突变和对吉非替尼的良好反应，但 EGFR 突变对影像学特征的影响尚不清楚。
所有在 2005 年 3 月至 2011 年 5 月期间新诊断为 NSCLC 时同时检测到脑转移的 NSCLC 患者，根据 EGFR 突变状态进行分组。比较各组脑肿瘤数量、最大脑肿瘤大小和肿瘤周围脑水肿大小。
符合标准的 57 例患者分为三组：野生型 EGFR 组（31 例）、外显子 19 缺失组（18 例）和外显子 21 点突变组（8 例）。外显子 19 缺失组的脑转移瘤数量更多，体积更小，肿瘤周围脑水肿更小（P = 0.024，P = 0.0016，P = 0.0036）。外显子 21 点突变组与野生型组在任何影像学值上均无显著差异。
我们的结果表明，外显子 19 缺失的 NSCLC 患者具有多发性小转移瘤伴小水肿的独特脑转移模式。这种转移模式可能类似于脑多发性转移。由于在其临床过程中是否会出现严重的神经症状尚不清楚，无论是否存在神经症状，都应考虑定期进行脑磁共振成像（MRI）评估。对脑转移特定模式的知识积累将有助于“个体化”管理方法的制定。
