Patients with active cancer face an increased risk of ischemic stroke. Also, stroke
may be an initial indicator of cancer. In patients with large vessel occlusion (LVO)
stroke treated with thrombectomy, analysis of the clot composition may contribute
new insights into the pathological connections between these two conditions.We compared
the content of 64 consecutively retrieved clots from LVO stroke patients with concomitant
active cancer and 64 clots from matched-control LVO stroke patients without a history
of cancer. Clots were analyzed with respect to histological composition by Martius
Scarlet Blue, von Willebrand factor (vWF), citrullinated histone H3 (H3Cit, a biomarker
of NETS), CD42b, and CD3 expression by immunohistochemistry. Orbit Image Analysis
was used for quantification. Differences between groups were tested using the Mann-Whitney
U-test and Chi-square Test.Clots from patients with concomitant cancer had a significantly
higher content of vWF (median 26 [IQR13-38]% vs. 10 [4-18]%, p < 0.0001) and H3Cit
(median 0.11 [IQR0.02-0.46]% vs. 0.05 [0.00-0.28]% p = 0.027) than controls. The presence
of collagen >1% within the retrieved clots was highly indicative of cancer, occurring
in 16/64 with active cancer and in 3/64 controls, p = 0.002. After correction for
multiple comparisons, the statistical significance for H3Cit was lost. Red and white
blood cells, platelets, fibrin, and expression of CD3 and CD42b did not differ between
the groups.Clots from LVO patients with concomitant active cancer possess distinct
characteristics, indicating an influence of cancer on the innate immune system, fibroblasts,
and the vascular endothelium in the formation of LVO clots.
