Researchers have now found that post-menopause, breast cancer patients who are overweight or obese, who incorporate hormone therapy into their treatment-and-who use nonsteroidal anti-inflammatory drugs (NSAIDs; eg, aspirin or ibuprofen) have a much lower rate of the cancer returning and a long interval should it return.
This subset of women has a relatively heightened risk of recurrence.
Their findings, published in the August 14 issue of Cancer Research, put forth a new option for lowering the incidence of breast cancer recurrence among this group of women.
Cancer researcher Linda deGraffenried, PhD, associate professor, School of Human Ecology, The University of Texas at Austin engineered the study in collaboration with Andrew Brenner, MD, an oncologist from the Cancer Therapy & Research Center, The University of Texas Health Science Center at San Antonio, and Murali Beeram, MD, a cancer specialist from the START Center for Cancer Care in San Antonio, Texas.
Employing a retrospective analysis of human subjects and cell cultures, the investigators found that NSAID use lowers the recurrence rate of the most common type of breast cancer-Er?-positive breast cancer--by 50 percent, and lengthens the duration of patients' disease-free interval by more than two years. ER-positive breast cancers, which multiply in response to exposure to the hormone estrogen, comprise about 75 percent of diagnoses.
The findings are preliminary, the researchers note, and further studies are being carried out to verify the results.
"Overweight or obese women diagnosed with breast cancer are facing a worse prognosis than normal-weight women," deGraffenried says. "We believe that obese women are facing a different disease. There are changes at the molecular level. We seek to modulate the disease promoting effects of obesity."
The researchers initially scoured medical records of 440 breast cancer patients, observing the prognoses of those who took NSAIDs versus those who did not.
The researchers created a second study to investigate how breast cancer cells act in the body. By immersing ER?-positive breast cancer cells in blood serum from obese women, they aimed to copy the conditions that encourage tumors to multiply, reproduce, and metastasize.
While the action that induces breast cancer in obese women to be more destructive and less receptive to treatment is not thoroughly understood, the researchers suggest that inflammation plays a key role. Their data also suggest inflammation negatively impacts the efficacy of aromatase inhibitors, a class of cancer drugs often prescribed to thwart cancer recurrence.
"Clinicians are finding that the five-year recurrence rate for postmenopausal women is much higher on aromatase inhibitors when the patient is obese," deGraffenried says. "We would like to identify which women are most likely to benefit from interventions like adding NSAIDs to treatment regimens."
Researcher Laura Bowers, The University of Texas at Austin, who oversaw the cell culture segment of the study, proposes that overweight or obese postmenopausal women - those at greater risk for breast cancer development - might profit from taking a low-dose aspirin daily. "What this study does is present great promise that a fairly inexpensive and nontoxic agent might benefit obese and overweight breast cancer patients who are at a higher risk of aromatase inhibitor failure - but further studies are needed to confirm these results," Bowers says.
An extended prospective study is on the drawing table to pinpoint disease biomarkers and keep track of patient response to the addition of NSAIDs to breast cancer treatment.