Abstract 1591P
Background
Cancer patients have high increased risk of Venous Thromboembolism (VTE) and treatments have changed lately. ISTH guidelines suggest rivaroxaban and edoxaban as alternatives to Low Molecular Weight Heparin (LMWH) for VTE treatment in certain cancers with low bleeding risk. However, little is known about safety and effectiveness from observational studies in routine clinical use. This is one of 3 studies in the OSCAR program. Optimal anticoagulation treatment duration in cancer patients remains an open question. A minimum of 6 months is recommended or longer if VTE recurrence risk is high. Preventing VTE recurrence must be balanced with bleeding risk. Study aims are to compare incidence of recurrent VTE, bleedings (hospitalization) and death in patients on DOACs versus LMWH.
Methods
Cohort study using Swedish national registers. All patients diagnosed with cancer 2013-2019 aged 18+ were identified in the Cancer Register and linked to Patient, Prescribed Drug, Population, and Cause of Death Registers. Eligible cancer patients with subsequent (index) VTE will be followed to recurrent VTE, bleeding, death, emigration or end of 2020. Up to 15 years look-back from index date will be used. Propensity score overlap weighting method will be used for confounding control for differences in covariates between DOAC and LMWH groups.
Results
In total 10403 individuals irrespective of VTE treatment were included, 55% men, 68% aged 65+, distributed by cancer site, type of VTE and selected comorbidities. Table: 1591P
Cancer site, VTE type at index and selected comorbidities
| Characteristic | Value | Proportion (%) |
| Cancer site | Oral/pharynx | 1.3 |
| Digestive | 31 | |
| Respiratory/intrathoracic | 16 | |
| Bone/articular cartilage | 0.2 | |
| Melanoma | 1.7 | |
| Mesothelial/soft tissue | 1.2 | |
| Breast | 9.5 | |
| Female genital | 8.1 | |
| Male genital | 7.0 | |
| Urinary | 6.3 | |
| Eye, brain, CNS | 5.8 | |
| Thyroid/endocrine | 0.9 | |
| Ill-defined, secondary, unspecified | 4.5 | |
| Lymphoid, hematopoietic, or related | 6.5 | |
| Index VTE type | DVT | 39 |
| DVT+PE | 5 | |
| PE | 56 | |
| Comorbidities with 15 years look-back | Thrombophilia | 0.8 |
| Heart Failure | 7 | |
| Diabetes | 14 | |
| Hypertension | 43 | |
| Bleeding (hospitalized) | 25 |
Conclusions
Analytic results will be presented at the ESMO conference.
Clinical trial identification
NCT05150938.
Editorial acknowledgement
Legal entity responsible for the study
Bayer AG.
Funding
Bayer AG.
Disclosure
M. Linder: Non-Financial Interests, Personal, Writing Engagements: Bayer AG; Financial Interests, Institutional, Research Grant, I am an employee of the Centre for Pharmacoepidemiology, Karolinska Institutet, which receives grants from several entities (pharmaceutical companies, regulatory authorities, and contract research organizations) for performance of drug safety and drug utilization studies: Several; including Bayer.