Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD.
Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD.
Clin Colorectal Cancer. 2020 Dec;19(4):263-269. doi: 10.1016/j.clcc.2020.09.002. Epub 2020 Sep 12.
Current literature suggests that brain metastasis is an infrequent occurrence in metastatic colorectal cancer. Outside of rare autopsy studies, these retrospective reports describe the incidence of symptomatic brain metastasis and therefore lack a description of the incidence in asymptomatic patients. With improved survival and a lack of routine brain imaging, the true incidence of brain metastasis among patients with metastatic colorectal cancer is likely under-recognized. At our research institution, protocol criteria require brain imaging regardless of neurologic symptoms. Therefore, we aim to describe the incidence of asymptomatic brain metastases in patients with metastatic colorectal cancer.
This study included patients with metastatic colorectal cancer enrolled onto a clinical trial screening protocol at the National Cancer Institute that underwent brain imaging (n = 171) between 2010 and 2019.
The median age of patients at initial colorectal cancer diagnosis was 48.1 years. Most had stage IV disease with synchronous metastases. Twenty-five (14.6%) patients were identified with brain metastases, of which 19 (76%) were asymptomatic. Those with asymptomatic lesions were more likely to have presented with synchronous metastases, have a shorter time from primary diagnosis to development of metastatic disease, and have smaller brain metastases.
We identified a high number of asymptomatic brain metastasis and subsequently a higher cumulative incidence of brain metastases in patients with metastatic colorectal cancer than historical reports would suggest. This may represent a heretofore unknown aspect of the natural course of disease now being exposed owing to an increasing life expectancy of these patients and could play a pivotal role in therapeutic decisions.
目前的文献表明，脑转移在转移性结直肠癌中并不常见。除了罕见的尸检研究外，这些回顾性报告描述的是有症状脑转移的发生率，因此缺乏对无症状患者发生率的描述。由于生存期的延长和缺乏常规脑部成像，转移性结直肠癌患者中脑转移的真实发生率可能被低估了。在我们的研究机构，根据方案标准，无论是否有神经系统症状，都需要进行脑部成像。因此，我们旨在描述无症状转移性结直肠癌患者中脑转移的发生率。
本研究纳入了 2010 年至 2019 年期间在国家癌症研究所接受脑部成像检查的入组临床试验筛选方案的转移性结直肠癌患者（n=171）。
初次结直肠癌诊断时患者的中位年龄为 48.1 岁。大多数患者为 IV 期疾病，伴同步转移。25 名（14.6%）患者被诊断为脑转移，其中 19 名（76%）为无症状。无症状病变患者更有可能同时出现转移，从原发诊断到发生转移性疾病的时间更短，且脑转移灶更小。
我们发现大量无症状脑转移，继而在转移性结直肠癌患者中发现更高的累积脑转移发生率，高于既往报告提示的发生率。这可能代表着这些患者预期寿命延长而出现的疾病自然病程中迄今未知的一个方面，并且可能在治疗决策中发挥关键作用。
