Objectives: We sought to determine whether postmenopausal women on chronic anticoagulation were diagnosed with endometrial cancer at an earlier stage.

Methods: A retrospective case-control study of women at a tertiary care medical center with a diagnosis of Endometrioid Adenocarcinoma on chronic anticoagulation at time of diagnosis in comparison with patients not on anticoagulation was performed. Patients with personal history of cancer, including breast cancer, non-postmenopausal bleeding, and non-Endometrioid Adenocarcinoma histopathology were excluded. Anticoagulation was defined as use of Enoxaparin, Warfarin, Apixaban, Rivaroxaban or Clopidogrel. Indications for anticoagulation included atrial fibrillation, deep vein thrombosis/pulmonary embolism, or stroke. The primary outcome was Endometrioid Cancer stage (I, II, III/IV and X). The secondary outcomes were duration of bleeding to presentation and presentation to diagnosis. Statistical analysis was performed using Wilcoxan-Rank Sum Test and Cochran-Armitage Trend Test.

Results: 25 postmenopausal patients met the inclusion criteria for being treated in the last 10 years. 100 controls not on anticoagulation (non-AC) were identified for a 4:1 comparison to obtain a 2-sided alpha level of 0.05. Results were divided into 3 groups: 1) All patients, 2) Non-white patients, 3) White patients. Subjects were controlled for age (P<0.001) and BMI (P<0.049). The results indicated that non-AC patients were more likely to be diagnosed at Stage 1 when compared to the AC patients in all 3 categories. The trend was not statistically significant for the non-white patients (p=0.133), but was statistically significant in the overall population (p<0.001) and White patients (p<0.001). No statistical significance was detected for duration from bleeding to presentation and presentation to diagnosis between the AC and non-AC groups. However, median days from bleeding to presentation are considerably larger for the non-AC than AC (Group 1: 42 vs 14 days, Group 2: 75 vs 33 days Group 3: 30 vs 14 days, respectively).

Conclusion: Non-anticoagulated patients had an earlier cancer stage at diagnosis. Although anticoagulated patients may present earlier, they have advanced cancer stage. These findings should prompt immediate evaluation of patients on chronic anticoagulation to optimize oncologic management and prognosis.

Citation Format: Ghadear Shukr, Tra Pham, Thomas Buekers. Effect of anticoagulation on the cancer stage at time of diagnosis of endometroid adenocarcinoma in a cohort of postmenopausal patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3344.