Research Year Student, Medical Student Aarhus University, Denmark
Background: Renal cell carcinomas (RCC) are more frequent in patients of higher age, and they are often accompanied by several comorbidities, which, together with their cancer diagnosis, increase the risk of developing a venous thromboembolism (VTE). Anticoagulants are used as treatment and prophylaxis for VTE, but their potential impact on RCC stage distribution is not well described.
Objectives: To investigate whether a history of VTE and/or use of anticoagulants at time of RCC diagnosis, affect the clinical stage distribution for patients undergoing surgical treatment.
Methods: We conducted a nationwide cross-sectional study and used Danish population-based health registries to retrieve information on anticoagulant prescriptions, previous VTEs and baseline characteristics. From The Danish National Patient Registry, we assembled a cohort of all Danish residents diagnosed with RCC who underwent tumour resection or nephrectomy between 2009-2020. We identified anticoagulants as ATC-codes starting with “BA01” and classified patients as current anticoagulant users if they had redeemed at least one prescription within 3 months before surgery. Patients who redeemed at least one prescription on anticoagulants between 5 years to 3 months before surgery were classified as former users.
We collected data on the clinical stage distribution within one month from date of surgery on all patients with a histological confirmed RCC. We excluded patients who had received immunotherapy within one year prior to RCC diagnosis or with previous cancer diagnosis. Using linear regression, we computed crude and adjusted prevalence rate ratios (PRR) for each disease stage with adjustment for potential confounders.
Results: The cohort included a total of 4579 patients who were diagnosed with RCC and underwent surgical treatment. In all, 1134 patients were current anticoagulant users at time of surgery, and they had a slightly higher prevalence of stage I disease (PRR 1.09 [0.98–1.22]) and a lower prevalence of stage II disease (PPR 0.76 [0.60-0.97[)]) compared to non-users. There was no difference between the two groups when looking at the prevalence for stage III disease (PRR 0.97 [0.84–1.12]) A similar pattern was found among the 499 patients identified as former anticoagulant users (stage I: PRR 1.12 [0.97-1.28], stage II: PRR 0.81 [0.59–1.08] and stage III: PPR 0.93 [0.77–1.11]), and also among the 155 patients with a history of VTE (stage I: PRR 1.08 [0.87–1.32], stage II: PRR 0.50 [0.24–0.92] and stage III: PPR 1.07 [0.80–1.41]).
Conclusions: Our nationwide analyses suggest that both current and former anticoagulant users and patients with a history of VTE tend to be diagnosed at an earlier disease stage. Possibly, this is explained by their increased risk of bleeding, prompting diagnosis.
