Chemotherapy plus ICI treatment ups VTE risk in cancer patients

Combination treatment with immune checkpoint inhibitors (ICI) and chemotherapy is associated with a higher risk of venous thromboembolic events (VTE) in adult cancer patients, reveals a study. In addition, a similar VTE disease course is seen after ICI exposure, irrespective of other immune-related adverse events (irAEs).

Of note, “[c]o-existing gastrointestinal irAE with VTE is associated with superior overall survival,” the authors said.

A retrospective, single-centre study was conducted to explore the clinical outcomes of adult cancer patients who developed a VTE within 2 years of ICI initiation. Those with VTE of alternate causes apart from malignancy and cancer therapy were excluded.

The authors classified eligible patients into those with gastrointestinal irAE, nongastrointestinal irAE, and no irAE. They also selected a control group with ICI exposure without irAE and VTE for comparative analysis.

Of all patients treated with ICI, 1,891 (17.2 percent) had a VTE diagnosis. Overall, 501 (4.6 percent) had no aetiology for VTE apart from malignancy and cancer therapy, of whom 137 were included and classified as follows: 44 gastrointestinal irAE, 42 nongastrointestinal irAE, and 51 no irAE.

Chemotherapy within 6 months of ICI therapy appeared to result in a higher VTE risk. No difference was observed in the clinical course between patients exposed to chemotherapy vs ICI therapy alone, time from ICI initiation to VTE, and VTE type, recurrence, or related hospitalization.

Although no difference was seen in VTE-related mortality, patients with gastrointestinal irAE were found to have lower all-cause mortality and better overall survival.

“Prospective studies are needed to evaluate the relationship between ICI therapy and VTE and irAE impact on VTE outcomes,” the authors said.