Circulating tumor cells (CTCs) are cells that have separated from a solid cancerous lesion and entered the bloodstream. They play a crucial role in driving the metastatic spread to distant organs, which is the leading cause of cancer-related deaths. Various concepts for blood purification devices aiming to remove CTCs from the blood and prevent metastases have been developed. Until now, it is not clear if such devices can indeed reduce new metastasis formation in a significant way. Here, we present a simple theoretical model of CTCs in the bloodstream that can be used to predict a reduction in metastatic burden using an extracorporeal or intracorporeal blood purification device. The model consists of a system of ordinary differential equations that was numerically solved and simulated. Various simulations with different parameter settings of extracorporeal and intracorporeal devices revealed that only devices implanted directly in tumor-draining vessels can reduce the metastatic burden significantly. Even if an extracorporeal device is used permanently, the reduction in metastases is only 82%, while a permanently operating implanted device in the tumor-draining vessel would achieve a reduction of 99.8%. These results are mainly due to the fact that only a small fraction of CTCs reaches peripheral circulation, resulting in a proportionally small amount of purified blood in extracorporeal devices.
循环肿瘤细胞（CTCs）是从实体癌病灶脱离并进入血液的细胞。它们在驱动癌细胞向远处器官转移扩散过程中起着关键作用，而转移是癌症相关死亡的主要原因。目前已有多种旨在清除血液中CTCs以预防转移的血液净化装置设计方案被提出。但迄今为止，此类装置是否能显著减少新转移灶的形成尚不明确。本文提出一种简化的血液中CTCs理论模型，可用于预测体外或体内血液净化装置对转移负荷的降低效果。该模型由常微分方程组构成，并通过数值求解和模拟进行分析。针对体外与体内装置不同参数设置的多组模拟结果显示，只有直接植入肿瘤引流血管的装置才能显著降低转移负荷。即使永久使用体外装置，转移灶减少率仅为82%，而永久运行于肿瘤引流血管的植入装置可实现99.8%的减少率。这些结果主要源于仅有少量CTCs进入外周循环，导致体外装置的血液净化量按比例减少。
肿瘤(癌症)患者之家