Stroke Survivors May Face Greater Cancer Risk

— Ischemic stroke increased likelihood of cancer within 2 years of the event.

MedicalToday
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NASHVILLE, Tenn. -- Survivors of ischemic stroke appear to have an increased short-term risk for skin cancer, prostate cancer, and other malignancies, findings from a 2-year follow-up study suggest.

The age-adjusted incidence for malignancies among stroke survivors included in the study was 20% higher than that reported in the general population 1 year after the stroke and 40% higher at 2 years.

Having incident cancer was also associated with a threefold greater risk for death among stroke survivors in a 2-year follow-up study.

Action Points

  • Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

Study findings were reported here at the American Heart Association/American Stroke Association's International Stroke Conference 2015 by researcher , of the University of Minnesota.

Stroke survivors have an elevated risk of dying in the years following the event, and this risk is not entirely explained by deaths from cardiovascular causes, Qureshi noted. He said the new findings may partially explain this increased mortality, and they have implications for the management and follow-up of these patients.

"From a public health perspective we have always considered cancer and stroke to be mutually exclusive diseases," he said. "I think this work points to the fact that they may not be."

Skin Cancer Was Most Common Diagnosis

Qureshi and colleagues included 3,247 survivors of nondisabling ischemic stroke enrolled in the study in their analysis.

The mean age of the cohort was 66 (±11 years) and 2,013 of the included study participants were men.

Within 2 years of the stroke event, 133 of the survivors received a diagnosis of cancer. Breakdown by cancer type included 47 skin cancers (35%), 24 prostate cancers (18%), eight breast cancers (6%), seven lung cancers (5.3%), six colon cancers (4.5%), five bladder cancers (3.8%), four esophageal cancers (3.0), and 32 other cancers (24%).

The majority of the cancers were diagnosed between 12 and 24 months after the stroke, and most baseline characteristics between those who did and did not have a later cancer diagnosis were similar.

The analysis revealed that:

  • The age-adjusted annual rate of cancer in patients with ischemic stroke over 1 year after recruitment was 581.8/100,000 persons, which was higher than the age-adjusted cancer rate of 486.5/100,000 persons in the general population (SIR 1.2; 95% CI 1.16-1.24).
  • This risk continued to be higher in the ischemic stroke patients 2 years after follow-up (1,301.7/100,000 versus 911.5/100,000 persons in the general population (Standardized incidence ratio or SIR 1.4, 95% CI 1.2-1.6).
  • Stroke survivors who developed cancer had a higher risk for death (OR 3.1, 95% CI 1.8-5.4), fatal/disabling stroke or death (OR 2.3, 95% CI 1.4-3.7), and composite endpoint of stroke, coronary heart disease, and/or death (OR 1.4, 95% CI 1.0-2.2) compared with the survivors without a cancer diagnosis.

Inflammation, Surveillance May Explain Link

While many risk factors for stroke and certain cancers are the same, Qureshi said further study will be needed to determine if this is the main mechanism linking the two diseases.

who is medical director of the Mercy Health Hauenstein Neuroscience Center, in Grand Rapids, Mich., suggested that the common denominator may be systemic inflammation.

"If you look at cancer and cardiovascular disease there is the common pathway of inflammation," he said.

AHA/ASA spokesman , of the Medical University of South Carolina, Charleston, suggested that the observed link may be largely due to increased medical surveillance of stroke survivors.

"When someone has a stroke they are going to be under increased surveillance compared with the general population," he said. "This might explain why more stroke survivors are discovered to have cancer when the underlying rates may not be that different."

Qureshi agreed that this may explain some or all of the observed association. He said the high rate of skin cancers seen in the study population appears to support this hypothesis.

Disclosures

The researchers declared no relevant relationships with industry.

Primary Source

International Stroke Conference

Source Reference: Qureshi A, "Incident cancer in a cohort of 3247 cancer diagnosis free ischemic stroke patients" ISC 2015; Abstract 210.