(TCP005) THE RELATIONSHIP BETWEEN ABO BLOOD GROUPS AND COAGULATION PROFILE IN WOMEN WITH CANCER UNDERGOING CHEMOTHERAPY

Background: Assembled evidence in previous literature has suggested that ABO blood groups are implicated in coagulation and thrombotic disorders. Non-O blood groups have been associated with a higher risk for thrombosis amongst cancer patients. Yet, research on the impact of ABO in different cancer types lacks rigor particularly in light of other risk factors for thrombosis (e.g chemotherapy). This study aimed to investigate the effect of ABO on coagulation profile and chemotherapy-induced hypercoagulability in breast and gynecological cancer patients.

METHODS AND RESULTS: A total of 15 female patients with newly diagnosed breast or gynecological cancer were recruited from the Kingston Health Sciences Centre oncology units. Demographic, clinical characteristics and patient and cancer related VTE risk factors including Khorana score were gathered. Blood samples were prospectively collected prior to chemotherapy as well as after the first cycle. Coagulation profile for each sample was assessed quantitatively using the global haemostatic assay Thromboelastography (TEG® 5000). Five different TEG parameters were analyzed. Average basal TEG parameters (R time, K time, alpha angle, maximal amplitude, and coagulation index) were compared with post-chemotherapy levels. Additionally, each patient’s coagulation profile was assessed individually to examine the presence of a hypercoagulability status using stringent criterion. A comparative TEG analysis was then conducted between non-O and O blood groups to examine the relationship using independent student t-test and Chi-Square Tests.
Of the 15 patients, 11 exhibited non-O blood groups and 4 with an O blood group. Average age at diagnosis for all patients was 63.5 years. Detailed patients' characteristics are provided in table 1. 73% (8/11) of patients in the non-O blood group were hypercoagulable post-chemotherapy as compared to 50% (2/4) for the O blood group. No significant association was observed between blood type and overall hypercoagulability status (p = 0.409). However, following chemotherapy, non-O blood groups showed significant changes in R time, K time, and alpha angle towards hypercoagulability (R: p = 0.01; K: p = 0.003; Alpha: p = 0.004) (Table 2). Two patients (A-blood group) developed pulmonary embolism within 6 months of starting of chemotherapy; both were hypercoagulable on TEG.

Conclusion: Although ABO blood groups do not appear to be direct predictors for hypercoagulability after chemotherapy, specific TEG parameters (R time, K time, Alpha Angle) have the potential to distinguish between O and non-O patients’ risk for thrombosis. Further studies with larger sample sizes are needed to verify these findings.