Obesity Interferes with Breast Cancer Treatment

Obese postmenopausal women react differently to breast cancer treatment, a new study has found.

The researchers have found that obesity affects a common drug that is used to treat breast cancer in women who have hit menopause.

The study was conducted by scientists at the University of Auckland.

Aromatase inhibitors block the enzyme aromatase and lower production of a hormone called estrogen. The hormone is known to help the tumors to grow and develop.

These inhibitors are available as pills and are considered to be effective against early-stage, hormone-receptor-positive breast cancer.

The researchers used data from both observational and intervention studies to find whether or not obesity affects breast cancer treatment.

"AIs may be less effective in obese women due to the greater quantity of aromatase in peripheral fatty tissue," said study author Professor Mark Elwood, an expert in cancer epidemiology from the University of Auckland.

"Outcome measures included overall survival, disease-free survival or time to progressive disease, survival from the start of therapy, mortality measures, local or distant recurrence of primary cancer and time to recurrence," said co-author, medical oncologist, Dr David Porter, according to a news release. "The systematic review showed a trend towards a negative effect of obesity on AI efficacy, but the size of the effect (in post-menopausal hormone receptor positive breast cancer), and whether it is the same with all AIs is difficult to determine."

Scientists said that more research is needed to understand how obesity affects drug response. AIs are given lower doses. The researchers say that if further studies confirm the findings, then doctors might consider giving heavy patients higher dose of the drug.

Obesity is growing at an incredible pace. By 2030, around half of the world's population will be obese. Past research has shown that obesity raises the risk of several health complications such as heart disease or diabetes. The disease is also known to affect risk of cancers and treatment outcomes.