Clinical Practice Statement on Direct Oral Anticoagulant Use in Gyn Onc Released

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in women with gynecologic malignancies. The January 2021 edition of Gynecologic Oncology has published  “Direct oral anticoagulant use in gynecologic oncology: A Society of Gynecologic Oncology Clinical Practice Statement,” to provide clinical data and overall quality of evidence regarding the use of direct oral anticoagulants (DOACs) in this patient population. Specifically, it reviews patient selection, safety measures, and nuances of perioperative use of these medications. Lead author Gregory Gressel, MD, MSc, noted that while other guidelines have been published by the American Society of Clinical Oncology (ASCO), National Comprehensive Cancer Network (NCCN), and the International Society on Thrombosis and Haemostasis (ISTH), this is the first SGO statement critically evaluating the evidence for using DOACs in patients with gynecologic cancer.

The authors found that:

• Apixaban, edoxaban and rivaroxaban are acceptable choices for long term treatment of gynecologic cancer-associated VTE in carefully selected patients without high risk of bleeding.
• Apixaban or rivaroxaban are acceptable choices for VTE prophylaxis in ambulatory outpatients initiating chemotherapy with a Khorana Score of 2 or higher.
• Apixaban is a safe alternative to low molecular weight heparin for extended duration postoperative prophylaxis after laparotomy for gynecologic cancer.

The scope of the clinical practice statement is limited to DOAC use in gynecologic oncology rather than a broad discussion of VTE prophylaxis and management in general, and is based on DOAC trials conducted primarily in mixed populations with different cancer subtypes. Because there is very limited data in gynecologic cancer-specific populations, the results of these studies represent the best available evidence to support treatment recommendations in patients. According to the practice statement, members of the SGO Clinical Practice Committee believe that the results of these studies may be extrapolated, with caution, to VTE treatment and prophylaxis for patients with gynecologic cancer.

“One of the challenges in summarizing the extant literature on use of DOACs in patients with cancer is heterogeneity of study design and heterogeneity of study populations examined,” explained Dr. Gressel. “Many trials include mixed populations of patients with and without cancer or mixed populations of patients with multiple cancer subtypes. Some of these studies include relatively high percentages of patients with hematologic malignancies such as leukemia and lymphoma (which are associated with high risk of VTE) and relatively low percentages of patients with gynecologic cancer. These studies also employ VTE-risk scoring algorithms which have not been extensively validated for use in populations with gynecologic cancer. In this era of precision medicine, it’s hard to argue that all cancers should be managed the same way. We don’t even know with respect to VTE risk if all gynecologic cancers should be managed the same way.”

Dr. Gressel added that overall, the data suggest that DOACs are a safe and effective alternative to low molecular weight heparins for prophylaxis and treatment of cancer-associated VTE, but there is an increased risk of bleeding seen in some patient populations, such as those with upper gastrointestinal cancers.

“It would be ideal to conduct our own prospective studies examining safety and efficacy of DOACs in women with gynecologic cancer, but these studies are expensive to conduct and take time,” he said. “I think as practice patterns gradually change and physicians shift towards prescribing DOACs over low molecular weight heparin, we will develop cumulative retrospective data that can be used to examine safety and efficacy.

“We are currently working on a study examining DOAC prescription patterns nationwide. I think these recommendations will provide gynecologic oncologists with the information they need to make informed decisions regarding DOAC prescriptions for their patients.”