The goal of this observational study is to learn about the long-term efficacy and safety of extended anticoagulant treatment in patients with cancer associated thrombosis. (CAT) The main question it aims to answer is:

• Does extended prophylactic dose anticoagulant provide comparable efficacy and safety to therapeutic dosing after 6-month treatment of anticoagulant? The medical record data of participants who's already received for at least 6-month anticoagulant treatment upon regular medical care for CAT will be collected and analyzed about their recurrent thrombosis, anticoagulant related bleeding, and survival outcome.

Adult patients aged ≥18 years with histopathological confirmed cancer, treated at Thammasat University Hospital and Panyananthaphikkhu Chonprathan Medical Center between January 2012 and December 2022, were eligible for inclusion.

Patients were initially screened using ICD-10 diagnostic codes C00-D009 for malignancy in conjunction with codes for venous thromboembolism (I82.-, other venous embolism and thrombosis; K55.0, mesenteric vein thrombosis; I82.0, hepatic vein thrombosis; K75.1, phlebitis of the portal vein; and I26.-, pulmonary embolism). Eligible patients required to have a radiologically confirmed diagnosis of cancer-associated thrombosis (CAT) and to have received anticoagulation therapy for at least six months. Clinical data were extracted from the Computerized Provider Order Entry (CPOE) system.

Here's a polished version of your Inclusion and Exclusion Criteria section with grammar, spelling, and phrasing corrected for clarity and formal research style:

Inclusion Criteria

• Adult patients aged ≥18 years
• Histopathologically confirmed cancer
• Radiologically confirmed diagnosis of cancer-associated thrombosis (CAT)
• Received anticoagulation therapy for at least six months Exclusion Criteria
• Patients who do not meet the inclusion criteria

Patients treated at Thammasat University Hospital or Panyananthaphikkhu Chonprathan Medical Center.