Women with breast cancer are more likely to die of cancer after experiencing a heart attack, according to the findings of a July 13 study in Nature Medicine.
Researchers from New York University (NYU) led a 23-person team that analyzed more than 1,700 early-stage breast cancer patients. The authors found breast cancer patients who also experienced a heart attack, stroke, or heart failure had a greater risk of death, cancer recurrence, and cancer spread.
Furthermore, mice with breast cancer had a twofold increase in tumor volume less than a month after the researchers cut blood flow to the coronary artery, simulating a heart attack. These mice also experienced a 60% increase in the proportion of immature white blood cells in tumors.
The findings in mice and humans demonstrate that heart attacks and other blood flow-reducing events may trigger a pro-cancer immune reaction, the authors noted. These changes may make immune cells in breast cancer patients less able to respond to tumors.
"By blunting the immune system's assault on cancer cells, a heart attack appears to provide an environment that enables tumor growth," stated author Kathryn Moore, PhD, the director of the Cardiovascular Research Center at the NYU Grossman School of Medicine in a press release.
The authors cautioned future studies are needed to support their findings. However, the results suggest patients with breast cancer may benefit from aggressive management of cardiovascular risk factors.
"Given the evidence of cross talk between cardiovascular disease and breast cancer, measures that lower the risk for a cardiovascular event, such as exercise and treating high cholesterol and high blood pressure, warrant further study as potential ways to keep patients' cancer from getting worse," stated lead author Graeme Koelwyn, PhD.
