Immune checkpoint inhibitors-associated thrombosis in patients with head and neck cancer: a study of the Spanish society of medical oncology (SEOM) thrombosis and cancer group.

Purpose: Both venous and arterial thrombotic events (VTE/AT) can be associated with Immune Checkpoint Inhibitors (ICI). However, there is a paucity of information apropos patients in routine clinical practice.

Methods: /Patients. This retrospective, multicenter study was promoted by the Thrombosis and Cancer Section of the Spanish Society of Medical Oncology (SEOM). Individuals with head and neck cancer who initiated ICI between 01/01/2015 and 31/12/2021 were recruited. Minimum follow-up was 6 months (except in cases of demise). The primary objective was to calculate the incidence of ICI-associated VTE/AT, with secondary objectives including the analysis of their impact on survival and the identification of variables predictive of VTE/AT.

Results: A total of 143 patients with head and neck cancer were enrolled. The incidence of VTE/AT during follow-up (median 8.6 months) was 2.8%. Survival analysis showed no significant differences (p = 0.644) between the group that developed VTE/AT (median 7.13 months, 95% CI 0-22.9) and the group that did not (median 9.86 months, 95% CI 6.3-13.4). The presence of liver metastases was predictive of VTE/AT (p < 0.05).

Conclusions: Thromboembolic disease associated with immunotherapy in patients with head and neck neoplasia does not significantly impact survival. The presence of liver metastases can predict these events.