There is a well-established link between obesity and an increased risk of breast cancer in postmenopausal women. Now new research shows that regular use of anti-inflammatory drugs like aspirin or ibuprofen can significantly reduce recurrence of breast cancer in such women. The study, published in Cancer Research, was conducted by researchers from the Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio and the University of Texas at Austin. 

Serum Differences In Obese And Non-Obese Patients

The researchers began by examining blood serum from CTRC breast cancer patients. They first placed the serum in a culture of fat cells that make estrogen, and then on breast cancer cells. The serum taken from obese patients caused an overactive growth of cancer cells compared to serum taken from non-obese patients.

"It looks like the mechanism is prostaglandins, which have a role in inflammation, and there's more of it in the obese patient serum," CTRC oncologist Andrew Brenner said in a statementProstaglandins, which are known to promote tumor growth, are produced by enzymes called cyclooxygenase (COX) enzymes. 

Previous studies have also shown that COX enzymes are the best known targets for non‐steroidal anti‐inflammatory drugs (NSAIDs) like aspirin and ibuprofen. In order to validate these studies further, scientists of the current research segregated obese breast cancer patients into those taking COX2 inhibitors (aspirin or ibuprofen) and those who did not. "Patients who were on COX2 inhibitors tended to have a lower recurrence rate," Brenner said.

Anti-inflammatory use reduced the recurrence rate of ERα positive breast cancer by 50 percent and extended patients' disease-free period by more than two years. ER-positive breast cancers are cancers identified by expression of estrogen receptor alpha. The cancers grow in response to exposure to the hormone estrogen and are most likely to respond to endocrine treatment. They are the most common form of the disease and account for 75 percent of the diagnoses. 

Brenner was aided in this research by Dr. Linda deGraffenried, from the University of Texas at Austin, and Dr. Murali Beeram, a cancer specialist from the START Center. 

But the investigators are quick to point that these results are preliminary and more research needs to be carried out for conclusive evidence. "Overweight or obese women diagnosed with breast cancer are facing a worse prognosis than normal-weight women," deGraffenried said.

The doctors also caution that women who are obese may be undergoing several changes in their bodies at the molecular level, which may promote other diseases.

"We would like to identify which women are most likely to benefit from interventions like adding NSAIDs to treatment regimens," deGraffenried said.

Source: deGraffenried L, Beeram M. Cancer Research. 2014.