Does the presence of a tumor thrombus mean metastasis?

Cancer thrombus generally indicates that the cancer has already metastasized, representing a significant marker of cancer progression. Specifically, a cancer thrombus refers to a pathological and physiological change in which cancer cells invade or aggregate within blood vessels or the lymphatic system during growth, proliferation, and metastasis, or induce abnormalities in blood coagulation, leading to impaired vascular function and disrupted blood flow, resulting in abnormal clotting and thrombus formation. The presence of a cancer thrombus often suggests that cancer cells have invaded blood or lymphatic vessels, typically indicating signs of cancer dissemination. However, the formation of a cancer thrombus does not necessarily mean that the cancer has widely spread; rather, it serves more as a warning signal, alerting patients to the need for more aggressive treatment measures.