结直肠癌脑转移的临床特征及预后因素分析

Clinical features and prognostic factors of brain metastasis from colorectal cancer

目的探讨结直肠癌脑转移的临床特征及预后因素。方法回顾性分析45例结直肠癌脑转移患者的临床特征，以及影响结直肠癌脑转移和预后的因素，探讨非手术单一治疗（非手术组）、放疗为主的综合治疗（放疗组）和手术为主的综合治疗（手术组）对患者预后的影响。结果45例结直肠癌脑转移患者中，64．4％的原发病灶来源于直肠，35．6％来源于结肠。80．0％患者合并颅外转移，其中57舟％合并肺转移，35．6％合并肝转移。合并肝转移的患者脑转移瘤的部位均为幕上，不合并肝转移者幕下转移率为44．8％，差异有统计学意义（P〈0．05）。剔除同步脑转移患者后，Dukes分期A期（仅1例）、B期、C期和D期患者的脑转移时间分别为24．0、36．0、29．0和12．0个月，差异有统计学意义（P〈0．05）。1年内发生颅外转移和未发生颅外转移患者的中位脑转移时间分别为12．0和38．0个月，差异有统计学意义（P〈0．05）。全组患者脑转移后的中位生存时间为6．0个月，1年生存率为21．1％。单因素分析显示，卡氏评分和脑转移瘤数目与患者的预后均有关（均P〈0．05）。多因素分析显示，脑转移瘤数目和治疗方式为结直肠癌脑转移患者的独立预后因素（均P〈0．05）。非手术组、放疗组和手术组患者的中位生存时间为4．0、10．0和12．0个月，手术组患者的中位生存时间与非手术组和放疗组比较，差异均有统计学意义（均P〈0．05）；非手术组患者的中位生存时间与放疗组比较，差异无统计学意义（P〉0．05）。结论直肠癌、原发病灶确诊时为Dukes分期D期、1年内发生颅外转移，尤其是合并肺转移的患者容易发生脑转移。合并肝转移患者幕上转移率较高，而不合并肝转移患者幕下转移率较高。结直肠癌脑转移的患者同时合并较高比例的其他脏器转移，预后较差，脑转移瘤数目和治疗方式为影响结直肠癌脑转移患者的独立因素；手术为主的综合治疗能最大程度地延长患者的生存时间。

Objective The aim of this study was to analyze the clinical features and prognostic factors in patients with brain metastasis from colorectal cancer （ CRC ）. Methods Clinical materials of 45 colorectal cancer patients who developed brain metastasis were collected, and the data and follow-up data of those patients were retrospectively analyzed. Results Most brain metastases were from rectal cancer （64.4%）, and 80.0% of the 45 cases had extracranial metastases. The most common extracranial metastatic site was the lung （57.8%）, followed by the liver （35.6%）. All the brain metastases in patients with liver metastases were supratentorial, while in contrast, 44.8% of the patients without liver metastasis had subtentorial metastasis, showing a significant difference between them （P〈0.05）. The interval time from diagnosis of CRC to the development of brain metastases in case of Dukes D stage was 12.0 months, significantly shorter than that in the cases of Dukes A stage （24.0 months） , B （36.0 months） and C （29.0 months） （P〈0.05）. The interval time was also shorter in the patients who developed extracranial metastasis within one year than those more than one year （ 12.0 months vs. 38.0 months） （P〈0.05）. The median survival time of patients with brain metastasis from colorectal was 6.0 months, with a 1-year survival rate of 21.1% and 2-year survival rate of 3.3% only. Univariate analysis showed that the median survival of patients with a KPS score of ≥70 was 8.0 months, significantly higher than 2.0 months in those with a KPS score of 〈70 （P〈0.05）. The median survival of patients with one or two brain metastases was 8.0 months, significantly higher than 4.0 months of those with 〉2 brain metastases （P〈0.05）. The median survival time after diagnosis of brain metastasis was 4.0 months for those who received monotherapy （only steroids, only chemotherapy or only radiotherapy） , significantly shorter than 10.0 months of patients who received ehemoradiotherapy, and 12.0 months of those who underwent surgery （ P 〈 0.05 ）. Comparing each two differently treated groups, the survival time of surgery combined with chemotherapy or radiotherapy group was significantly different from that of all of other groups （P〈0.05）. The median survival time of chemoradiotherapy group was longer than that of monotherapy, but the difference was not significant （P〉 0.05 ）. Multivariate analysis showed that brain metastases 〉2 and treatment modality type are independent prognostic factors for survival. Conclusions Patients initially diagnosed with a Dukes D stage primary colorectal tumor and occurrence of extracranial metastasis （especially, pulmonary metastasis ） within one year are associated to an increased risk of brain metastases and have a shorter survival time. Most brain metastases in patients with liver metastases are supratentorial, while many patients without liver metastasis have subtentorial metastasis. Brain metastases 〉2 and the type of treatment modality are independent prognostic factors for survival. The prognosis of patients who received chemoradiotherapy is better than those treated only with chemotherapy or radiotherapy. Some subsets of patients may benefit from surgery plus chemotherapy/radiotherapy.