Experts have warned that the innovative weight loss doses relied on by millions of weight losers and diabetics could cause breast cancer treatments to stop working.
The drugs, including Ozempic and Wegovy, have ushered in a new era in the battle against obesity, helping dieters lose up to a fifth of their body weight.
But American doctors following women being treated for an aggressive form of breast cancer have found that the injections “detrimentally affect” the way the body responds to chemotherapy and immunotherapy.
It means that patients who receive injections, known collectively as glucagon-like peptide-1, or GLP-1, receptor agonists, may have a higher risk of their cancers coming back.
Consultant clinical oncologist Dr John Glees said the findings were “concerning” and added: “These weight loss drugs are relatively new, so it is very worrying that patients taking them are less likely to be free of cancer after treatment.
In the study, hundreds of women with early-stage triple-negative breast cancer were followed during and after treatment.
A few dozen were already taking GLP-1 and continued to do so while receiving cancer treatment.
Two years later, tests showed that only 28 percent of women taking GLP-1 responded completely to cancer therapies and were cancer-free.
Experts have warned that the innovative weight loss jabs relied on by millions of slimmers and diabetics around the world could make breast cancer treatments stop working.
American doctors following women being treated for breast cancer have found that the injections, known collectively as glucagon-like peptide-1 or GLP-1 receptor agonists, “negatively affect” the way the body responds to the chemotherapy and immunotherapy.
More than twice as many (63 percent) of those not taking GLP-1 were cancer-free.
Dr. Bethania Santos, an oncologist and researcher at UT Southwestern Medical Center in Dallas, who presented the study today at the San Antonio Breast Cancer Symposium, said, “The use of GLP-1 during breast cancer therapy.
The researchers also discovered GLP-1 had infiltrated tumor cells and immune cells in samples taken from patients.
Although what this meant was not yet fully understood, Dr. Santon suggested that it could somehow make tumor cells more resistant to standard treatments.
Dr Glees added: “We know that obesity increases the risk of cancer, so drugs like Ozempic, which help people lose weight, could also reduce that risk.”
“The injections also appear to protect the heart and possibly the brain.
‘But we need to think very carefully about this new data and carry out more research.
“It’s important for patients not to panic, but equally, it’s vital for women to tell their cancer specialist if they are taking one of these GLP-1 medications while receiving cancer treatment.”
Checking your breasts should be part of your monthly routine so that you notice any unusual changes. Simply rub and feel up and down, in semicircles and circular motions around the breast tissue to identify any abnormalities.
Breast cancer symptoms to look out for include lumps and swelling, dimpling of the skin, color changes, discharge, and a rash or crusting around the nipple.
Ozempic, Wegovy and the similar drug Mounjaro are self-administered weekly.
Limited studies have suggested that weight loss injections may be helpful in reducing the risk of breast cancer and other types of cancer.
One in seven women in the UK are diagnosed with breast cancer in their lifetime (around 56,000 a year), making it the most common cancer in the UK.
The figure amounts to approximately 300,000 a year in the United States. About 85 percent of women diagnosed with breast cancer survive more than five years.
However, triple negative breast cancer (which accounts for around 15 per cent of all breast cancers in the UK and US) is much more difficult.
It typically grows and spreads faster than other types of breast cancer and has fewer treatment options.
On average, about 77 percent of women with triple-negative breast cancer will survive the cancer for five years or more after being diagnosed, but depending on the stage, the figure can drop to 12 percent.
Breast cancer specialist and author Dr Liz O’Riordan said: “This is an important study and more research is needed.”
‘It appears that GLP-1 may make cancer cells less responsive to chemotherapy and immunotherapy.
“This will mean that their cancers are much more likely to return.
‘On the other hand, we believe that giving GLP-1 to women after they have completed cancer treatment, to keep their weight down, may reduce the likelihood of cancer recurrence.
“We need to think more about how these patients are treated and do more research to understand what is happening.”