Abstract 7652: Plasma markers of hemostasis, fibrinolysis, and angiogenesis prior to androgen deprivation therapy (ADT) in progressive prostate cancer (PC) and associations with long-term thrombotic events and survival
Authors: Palmer Jessica S. , Thomas Charlene , Jacobs Nicole , Nanus David , Tagawa Scott T. 
Published: March 2024

Abstract
Background: PC is the third most common malignancy associated with thrombosis, procoagulants may play a role in tumorigenesis and progression, and patients (pts) with PC may have activation of the hemostatic system evident in plasma. The prognostic significance of these markers and their relationship to thrombotic events and overall survival (OS) are under-explored.
Methods: Patients &gt;18 years were included if they had progressive PC planned to start ADT, were &gt;6 months from surgery or RT, with no history of prior VTE, unexplained bleeding, current or planned anticoagulation, or an additional active malignancy. Plasma samples were obtained via peripheral venipuncture in tubes containing 3.2% sodium citrate and immediately placed on ice. Samples were analyzed for D-dimer, thrombin-antithrombin complex (TAT), IL-6, IL-8, VEGF, and tissue factor (TF) levels by ELISA. Patients had markers drawn at baseline (prior to initiation of ADT), 1 month, and 6 months after initiation.
Results: 40 patients were accrued with a median age of 68 years. At baseline, 29 (73%) had presence of metastases. Baseline median PSA was 15 and median PSA doubling time was 0.32. Baseline median hemoglobin was 13.85, platelets were 218, D-dimer was 322 ng/dL, IL-6 was 0 pg/mL, IL-8 was 0 pg/mL, TAT was 3 ug/L, VEGF was 21 pg/mL, and TF was 26 pg/mL. Median follow-up was 78 months. During follow up, 35 (87.5%) had metastases. 10 (25%) had thrombotic events (6 [15%] venous, 4 [10%] arterial) at median 37 months follow up. Median baseline age of pts with subsequent thrombotic events was 74, vs 67 in those without a thrombotic event. While there was no significant difference in baseline PSA between groups with and without clotting events, pretreatment PSA doubling time was significantly lower in pts with subsequent thrombosis (0.27 vs 0.35, p=0.047). Median baseline D-dimer and TF were higher in patients with subsequent thrombosis (D-dimer: 516 vs 282, p=0.10; TF: 36 vs 24, p=0.12). In univariate analysis, baseline IL-6 and VEGF were associated with OS (IL-6: HR=1.05, 95% CI [1.01,1.09], p=0.025; VEGF: HR=1.02, 95% CI [1.00,1.03], p=0.028). When controlling for presence of metastasis, baseline TAT was associated with OS (HR=1.05, 95% CI [1.00,1.11], p=0.055).
Conclusions: Plasma markers of hemostatic activation, fibrinolysis, and angiogenesis prior to initiation of ADT are associated with subsequent thrombotic events and overall survival years later. Further analysis will examine how these markers change over time with hormonal therapy.
Citation Format: Jessica S. Palmer, Charlene Thomas, Nicole Jacobs, David Nanus, Scott T. Tagawa. Plasma markers of hemostasis, fibrinolysis, and angiogenesis prior to androgen deprivation therapy (ADT) in progressive prostate cancer (PC) and associations with long-term thrombotic events and survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7652.