Background and importance Venous thromboembolic disease occurs in 10%–20% of cancer patients and results in high morbimortality. Cancer is associated with various factors that increase thrombotic risk; in addition, the incidence of cancer-associated thrombosis (CAT) is related to the type of tumour, staging and antineoplastic treatment.

Aim and objectives To analyse the prevalence of antineoplastic drugs associated with thrombosis and to identify the thrombotic risk in a cohort of patients with a CAT.

Material and methods A retrospective observational study, which included oncological patients admitted to a third-level hospital during 2019 with a diagnosis of CAT. Biodemographical, clinical and antineoplastic treatment-related variables were recorded.

Different sources associate some antineoplastic drugs to CAT (5-fluorouracil, cisplatin, doxorubicin, paclitaxel, among others). Besides, according to the American Society of Clinical Oncology (ASCO) Guidelines, stomach and pancreas (very high) and lung, lymphoma, gynaecological, bladder, testicles and kidneys (high) are the most related tumours to CAT.

The thrombotic risk prior to the initiation of chemotherapy was determined according to the Khorana Risk Score (KRS), where 3: high; 1–2: intermediate; 0: low, which considers: tumour location, body mass index (BMI) >35, haemoglobin <10 g/dL, leukocytes >11 000/µL and platelets >350 000/µL.

Results We included 50 (48% men) oncological patients, with a median age of 68 (54–75) years.

When CAT occurred, 42 (84%) patients were receiving antineoplastic treatment, 23 (55%) of them were associated with CAT: paclitaxel (30.7%), 5-fluorouracil (30.7%), cisplatin (15.4%), bevacizumab (7.7%), cetuximab (7.7%), doxorubicin (7.7%), others (15.4%). 6 patients received 2 CAT-associated drugs.

46% of patients had a tumour location associated with a very high (10% stomach, 10% pancreas) or high incidence (14% lung, 6% gynaecological, 4% kidney, 2% testicle) of CAT.

Patients were classified as low (36%), intermediate (50%) and high (14%) thrombotic risk according to the KRS. Of these, 55%, 61% and 20%, respectively, were receiving oncological treatment associated with CAT. 50% of low-risk patients (n=5) were receiving 2 CAT-related drugs.

Conclusion and relevance A high number of patients (55%) received oncological treatment associated with CAT.

According to KRS, a significant number of patients (64%) presented intermediate or high risk.

The majority of patients who were receiving oncological drugs associated with CAT presented low or intermediate risk of thrombosis according to KRS.

Although the analysed group is small, these results could be used to analyse the need to initiate thromboembolic prophylaxis in certain groups, beyond those of high risk.

References and/or acknowledgements 1. https://link.springer.com/chapter/10.1007%2F978-3-030–20315-3_6

2. https://ascopubs.org/doi/pdf/10.1200/JCO.19.01461

Conflict of interest No conflict of interest