为什么癌症患者更容易出现血栓？——重视癌症血栓风险

血栓是癌症患者常见的并发症之一。研究表明，癌症患者发生血栓的风险比普通人群高出9倍，是导致癌症患者病情恶化和死亡的重要原因之一。因此，了解癌症与血栓之间的关系，并采取有效的预防和治疗措施，对癌症患者及其家属来说至关重要。

癌症患者血栓风险增加的原因

癌症患者容易发生血栓的原因非常复杂，涉及肿瘤细胞本身的影响以及患者自身的生理状况。以下是主要的几类原因：

肿瘤细胞的直接作用

某些癌症细胞会分泌一种叫“组织因子”的物质，这种物质可以激活体内的凝血系统，导致血液中血栓的形成。除此之外，肿瘤细胞还可以与血小板结合形成“肿瘤-血小板聚集体”，这种聚集体不仅会引发血栓，还可以帮助肿瘤细胞躲避免疫系统的攻击，从而促进癌细胞的扩散和转移。

血液中血小板水平升高

许多癌症患者的血小板水平较高，而血小板在血栓形成中起着至关重要的作用。血小板可以与肿瘤细胞相互作用，使血小板聚集在肿瘤细胞周围，从而促使血液凝固形成血栓。研究表明，血小板水平较高的癌症患者，其血栓风险也显著升高，同时预后较差。

中性粒细胞胞外陷阱（NETs）

中性粒细胞是一种重要的免疫细胞，当它们受到刺激时，会释放一种叫做中性粒细胞胞外陷阱（NETs）的物质。NETs可以捕捉肿瘤细胞，但同时它也会激活血小板，促进血栓形成，从而增加患者血栓的风险。

患者自身状况的影响

许多癌症患者年龄较大，身体机能下降，伴有其他基础疾病（如高血压、糖尿病、心脏病等）。这些合并症本身就会导致血管内皮功能受损，增加血栓的发生风险。此外，很多癌症患者由于疾病进展或治疗的原因长期卧床，缺乏活动，导致下肢静脉血液淤滞，也极易引发深静脉血栓。

癌症治疗的影响

癌症治疗，如手术、化疗、放疗和某些靶向药物，也可能增加血栓风险。手术会直接损伤血管壁，使血液更容易凝结。某些化疗药物和激素治疗可导致血液黏稠度升高，增加血栓风险。静脉导管（如PICC导管）或输液装置的植入也可能刺激局部血管，引发血栓。

癌症患者应该如何预防血栓？

癌症患者在治疗过程中，特别是在接受化疗、手术或长期卧床时，应密切关注血栓的发生。一旦出现腿部肿胀、疼痛，或突发性胸痛、呼吸困难等症状，应立即就医。此外，患者应定期复查血小板水平和凝血功能，遵医嘱使用抗凝药物（如低分子肝素），并在条件允许时适当活动下肢，以促进血液循环，降低血栓风险。

结论

血栓是癌症患者常见且严重的并发症之一，其发生原因涉及多种因素，如肿瘤细胞直接作用、血液成分改变、患者年龄较大及长期卧床等。因此，癌症患者及其家属应高度重视血栓的预防和早期发现。通过积极与医生沟通，了解自身血栓风险，采取合理的预防措施，可以有效降低血栓对健康和生命的威胁，从而改善癌症治疗的整体预后。

Thrombosis is a common complication in cancer patients. Studies show that the risk of thrombosis in cancer patients is nine times higher than in the general population, making it one of the main factors contributing to disease progression and mortality. Therefore, understanding the relationship between cancer and thrombosis, as well as adopting effective prevention and treatment strategies, is crucial for cancer patients and their families.

Reasons for Increased Thrombosis Risk in Cancer Patients

The reasons for increased thrombosis risk in cancer patients are complex and involve both the direct effects of tumor cells and the patient’s physiological status. The main factors include the following:

Direct Effects of Tumor Cells

Some cancer cells secrete a protein called “tissue factor,“ which can activate the body‘s coagulation system, leading to clot formation in the blood. Additionally, tumor cells can bind to platelets to form “tumor-platelet aggregates.“ These aggregates not only trigger clot formation but also help tumor cells evade attacks from the immune system, thereby promoting cancer cell spread and metastasis.

Elevated Platelet Levels in the Blood

Many cancer patients have elevated platelet levels, and platelets play a critical role in clot formation. Platelets can interact with tumor cells, gathering around them and promoting blood clotting. Studies have shown that cancer patients with higher platelet levels have an increased risk of thrombosis and generally poorer prognosis.

Neutrophil Extracellular Traps (NETs)

Neutrophils, a type of immune cell, release a substance called neutrophil extracellular traps (NETs) when stimulated. While NETs can trap tumor cells, they can also activate platelets and promote clot formation, thereby increasing the risk of thrombosis in patients.

Patient‘s Own Condition

Many cancer patients are elderly, have reduced physical function, and suffer from other underlying health conditions such as hypertension, diabetes, or heart disease. These comorbidities can impair vascular endothelial function and increase the risk of thrombosis. In addition, many cancer patients are bedridden due to disease progression or treatment, leading to blood stasis in the lower extremities, which makes deep vein thrombosis more likely.

Impact of Cancer Treatments

Cancer treatments such as surgery, chemotherapy, radiotherapy, and certain targeted therapies can also increase the risk of thrombosis. Surgery can directly damage the vessel wall, making blood more likely to clot. Certain chemotherapy drugs and hormone therapies can increase blood viscosity and elevate thrombosis risk. The placement of intravenous catheters (e.g., PICC lines) or infusion devices can also stimulate local blood vessels and cause clot formation.

How Can Cancer Patients Prevent Thrombosis?

During treatment, especially when undergoing chemotherapy, surgery, or prolonged bed rest, cancer patients should be vigilant about the signs of thrombosis. If symptoms such as leg swelling, pain, sudden chest pain, or difficulty breathing occur, immediate medical attention should be sought. Patients should also regularly monitor platelet levels and coagulation function, follow the doctor’s recommendations for anticoagulant medication (such as low-molecular-weight heparin), and engage in gentle lower limb activities when possible to promote blood circulation and reduce the risk of thrombosis.

Conclusion

Thrombosis is a common and serious complication in cancer patients, and its occurrence is influenced by multiple factors such as direct effects of tumor cells, changes in blood composition, advanced patient age, and prolonged bed rest. Therefore, cancer patients and their families should pay close attention to the prevention and early detection of thrombosis. By actively communicating with healthcare providers, understanding personal thrombosis risks, and taking appropriate preventive measures, the health and life-threatening risks posed by thrombosis can be effectively reduced, ultimately improving the overall prognosis of cancer treatment.