(AB) Risk of Venous Thromboembolism Events in Prostate Cancer Patients

Publication Number: 318

Background: Venous thromboembolism (VTE) is a cause of complications in prostate cancer (PC) patients, induced by tumor and treatment associated factors such as hypercoagulability, vascular injury, and venous stasis. Yet real-world evidence on the VTE risk in association with clinical characteristics and treatments received in PC patients remains limited.

Objectives: To estimate the incidence of VTE events among PC patients in a real-world setting and to characterize potential risk factors

Methods: We conducted a retrospective cohort study using 4 US administrative claims databases (IBM MarketScan® Commercial Claims and Encounters [CCAE], Medicare Supplemental Beneficiaries [MDCR], Multistate Medicaid Database [MDCD], Optum de-identified Clinformatics® Datamart [Optum DOD]) and 1 electronic health record database (Optum EHR). We selected patients aged ≥18 years, diagnosed with PC, and having ≥365d prior observation, and categorized them into treatment groups of 1) radical prostatectomy (RP) monotherapy, 2) RP + neoadjuvant/adjuvant androgen-deprivation therapy (ADT), 3) radiotherapy monotherapy, 4) radiotherapy + neoadjuvant ADT, and 5) ADT monotherapy. We identified VTE events including deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring after the PC diagnosis. In each treatment group, time-at-risk starting from the treatment initiation was censored when another treatment was observed. Incidence rates (IR, /1000 person-years [PY]) for each outcome were calculated with patients with prior event excluded. Baseline characteristics prior to treatment were assessed as mean for continuous variables and proportion for binary variables in patients with versus without incident event.

Results: A total of 367,611, 402,408, 52,207, 636,031, and 474,394 PC patients from CCAE, MDCR, MDCD, Optum DOD, and Optum EHR, respectively, were examined (mean age of 58, 75, 68, 71, and 70 years, respectively). The crude IR (95% CI) ranged from 9.07 (8.88-9.27) to 21.5 (20.7-22.2) /1000 PY for VTE [7.02 (6.85-7.19) to 15.5 (14.9-16.2) /1000 PY for DVT, 4.05 (3.93-4.19) to 9.54 (9.07-10.0) /1000 PY for PE]. The IR were generally higher for patients who received ADT for any indication, and the lowest for those who received RP monotherapy. Compared to patients with no VTE, those who experienced incident VTE had higher comorbidity scores such as CHADS2, CHADS2VASc, Charlson index (Romano) and were more likely to have secondary malignancy, hospitalization, respiratory disorders within 1 year prior to start of PC treatment (standardized mean difference >0.1).

Conclusions: In this real-world study, the risk of VTE varied by PC patient characteristics and treatment. Future studies should further investigate risk factors to develop prevention and mitigation strategies.