Risk for Heart Attack, Stroke Five-Fold in Older Patients One Month Before Cancer Diagnosis

Older adults may be at an increased risk for a heart attack or stroke five months before they are even diagnosed with cancer — a risk that peaked in the month prior to diagnosis, according to a report published in Blood.

In turn, researchers from Weill Cornell Medicine, NewYork-Presbyterian and Memorial Sloan Kettering Cancer Center, suggested that such events could prompt cancer screening if warranted in certain older patients.

“For example, up to 10 percent of venous thromboembolism may be associated with occult cancer (cancer that is determined to be metastatic at the time of diagnosis, but a primary tumor cannot be identified),” the researchers wrote. “Therefore, venous thromboembolism, especially if unprovoked and in older patients, can initiate a malignancy screen, although this practice is not endorsed in current guidelines because of a lack of proven benefit in large randomized trials.”

In the retrospective, matched case-control study, the researchers evaluated the risks for heart attack and stroke in the year before cancer diagnosis among individuals aged 67 years and older who were newly diagnosed with breast (74,638 patients), lung (74,633 patients), prostate (82,099 patients) and colorectal (56,366 patients) cancers, as well as bladder, non-Hodgkin lymphoma, uterine, pancreatic and gastric cancers from January 2005 to December 2013. The study included 748,662 Medicare beneficiaries and compared patients with cancer to matched healthy controls using the Surveillance, Epidemiology, and End Results (SEER) registry.

On average, patients were 76 years old and the majority were female (52 percent). Overall, the risk for a heart attack or stroke was increased nearly 70 percent in the year leading up to patients’ cancer diagnoses.

While this risk appeared similar among both groups, it started to significantly increase approximately five months before diagnosis. This risk progressively grew one month prior, with a five-fold increase in the odds that a heart attack or stroke would occur in an individual who went on to be diagnosed with cancer (62% vs. 11%) compared with a healthy counterpart.

The rate of heart attack or stroke was highest in those with lung and colorectal cancers as well as patients diagnosed with stage 3 or 4 disease.

The researchers analyzed the risk for heart attack and stroke separately, for which both were increased in the months leading up to a cancer diagnosis; however, the risk for heart attack was slightly more common.

“These data suggest that some myocardial infarction and ischemic stroke events may be triggered, or potentially caused by, occult cancer,” the researchers wrote. “Future research is needed to identify clinically useful biomarkers for occult cancer in patients with arterial thromboembolic events and to determine the utility of cancer screening strategies in these patients, particularly among those with cancer risk factors or unexplained ‘cryptogenic’ events.”

In addition, they recommend for physicians to be vigilant about cancer screening in those who have experienced a heart attack or stroke. “In the meantime, we recommend that patients with acute myocardial infarction and ischemic stroke be up-to-date with their age- and gender-appropriate cancer screening, and that their clinicians pay close attention to, and have a low threshold to investigate, any symptoms or signs consistent with occult cancer, such as unexplained anemia or weight loss.”