High Risk of Recurrence in First-Time Cancer-Related Venous Thromboembolism

After first-time cancer associated venous thromboembolism, the risk of recurrence after 6 months was high and varied by cancer type and patient characteristics, according to research published in the International Journal of Cardiology.

The incidence of recurrence among patients with first-time cancer-associated venous thromboembolism was 5.2% in the first 6 months and 6.7% at 1 year.

Researchers evaluated the risk of recurrent venous thromboembolism with cancer-specific factors among Danish patients with active cancer and first-time venous thromboembolism. Data were obtained from nationwide databases with prospective information from the Danish health care system.

Patients aged 18 years and older with active cancer and venous thromboembolism and residing in Denmark between 2003 and 2018 were identified in the Danish National Patient Registry. Participants who survived the first 10 days after their first-time venous thromboembolism diagnosis were followed to the first subsequent diagnosis of venous thromboembolism, death, emigration from Denmark, or end of 2018, whichever came first. The analyses were reported at 6 months and 1 year.

The cohort included 34,072 patients (53% female; median age, 72 years). Among the participants, 16% were diagnosed with brain cancer, 11% with gastrointestinal cancer, 10% with breast cancer, 7.8% with lung cancer, 6.5% with hematologic cancer, 6.4% with gynecologic cancer, 4.6% with genitourinary cancer, and 37% with other cancer types. Deep vein thrombosis was diagnosed in 55% of the cohort, 45% had pulmonary embolism, and 2.6% had both diagnoses.

A total of 1755 recurrent venous thromboembolic events occurred within 1 year, of which 1352 were diagnosed within the initial 6 months of follow-up. The risk of recurrence was 5.1% at 6 months and increased to 6.7% at 1 year. The overall mortality risk was 26% at 6 months and 36% at 1 year, with the highest risk occurring in patients with lung cancer at 6 months and 1 year.

The recurrence risk after 6 months was comparable for men and women (5.2% and 4.9%, respectively) and among Ottawa risk score groups: 5.0% for low risk and 5.1% for high risk (subdistribution hazard ratio, 1.12; 95% CI, 0.97-1.30). Recurrence risks were 4.7% for localized stage cancer and 6.3% for distant cancers, and they were similar during follow-up with surgery (5.3%) and anticancer treatment (5.1% for chemotherapy, 5.0% for radiotherapy, 4.5% for endocrine therapy, and 5.4% for immunotherapy at 6 months).

The risks were 6.5% for patients with genitourinary cancer, 6.1% for lung cancer, 5.6% for gastrointestinal cancer, 5.2% for brain cancer, 5.1% for hematologic cancer, 4.7% for gynecologic cancer, 4.1% for breast cancer, and 4.8% for other cancer types, compared with the overall cohort risk of recurrence of 5.2% at 6 months.

Among several limitations, the datasets did not include information on sociocultural determinants of health such as race/ethnicity and lifestyle, and complete information was unavailable regarding cancer stage for all patients and cancer progression during follow-up. Data were also unavailable for site of first-time deep venous thrombosis and whether some venous thromboembolisms were incidentally diagnosed, for example, during routine scans for cancer, which may affect patients differently for age and cancer stage.

“Refining risk stratification for recurrence may improve decision-making regarding treatment duration after cancer-associated thromboembolism and ultimately lead to improvements in the net clinical benefit from anticoagulant treatment in this challenging patient population,” concluded the researchers.

Disclosure: Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures