Research indicates a strong correlation between cancer and thrombosis, with approximately 20% of blood clots in the U.S. being cancer-related, according to CDC data. Cancer patients face a 4-7 times higher risk of thrombosis compared to non-cancer individuals. Certain cancer treatments, such as chemotherapy and targeted therapy, elevate the likelihood of venous thromboembolism (VTE). Cancer patients with VTE exhibit a significantly higher hazard ratio (H.R.) of 3.4 compared to those without VTE. This study aims to explore three main topics: (1) Comparing the differences and similarities of leukocyte populations between cancer-associated thrombosis (CAT) and venous thromboembolism (VTE). (2) Characterizing the factors contributing to increased incidence of cancer-associated thrombosis (CAT), with the hypothesis that circulating tumor microemboli (CTM) may express more thrombosis-related proteins than CTCs. (3) Understanding the effects of aspirin or NOACs on cancer-associated thrombosis and CTM formation.