Cancer-related blood clotting may contribute to stroke, with risk appearing highest soon after a cancer diagnosis, a review of 82 studies suggests.
The analysis found that stroke linked to cancer-associated coagulopathy occurred predominantly within six months of diagnosis.
Many patients had metastatic cancer, meaning the disease had spread to other parts of the body, by the time they experienced a stroke.
Stroke is the most common neurological complication among people with cancer after brain metastasis, when cancer originating elsewhere in the body spreads to the brain.
Researchers in Spain reviewed 82 studies conducted between 2000 and 2025, examining the epidemiological, clinical, radiological and pathophysiological features of cancer-related stroke.
The review found that cancers affecting the inner lining of the lungs and pancreatic tissues were most frequently associated with stroke.
In these cases, the interval between cancer diagnosis and stroke was often particularly short.
The incidence of clots forming in major arteries peaked during the first year after cancer diagnosis. Stroke was the most common outcome in about 72 per cent of cases.
Although stroke risk declined after the first year, it remained higher than in the general population for as long as a decade.
The researchers said several complex biological processes could help explain the association between cancer and stroke.
One proposed mechanism involves mucin, a sticky molecule produced by some cancer cells, which researchers suspect may trigger the formation of platelet clumps.
“Proposed mechanisms include mucin-mediated platelet aggregation,” they wrote.
Membrane-bound particles circulating in the body and immune cells called neutrophils may also contribute to clot formation.
D-dimer, a small protein fragment left in the blood when a clot dissolves, may be used to identify signs of clotting in people with cancer.
“D-dimer is the biomarker most consistently associated with recurrence and mortality,” the researchers said.
An MRI pattern showing lesions in three separate regions of the brain can also be highly specific for cancer-related stroke.
The researchers said the mechanism connecting cancer and stroke remains largely unclear.
“Given the expected worldwide increase in cancer incidence and improvements in cancer survival,” the researchers noted, “burden of CAC-related stroke is likely to rise substantially in the coming years, highlighting the importance of improving its recognition and management.”
