By: Mia De Graaf
Slender women have a higher risk of developing breast cancer, a new study warns.
Scientists evaluated fat tissue from the breast and blood samples of 72 women with normal body-mass indices – less than 25.
They found that 40 percent of them had ominous inflammation in their breast fat tissue.
The reason, they believe, is because many women with healthy BMIs have larger fat cells in their breast tissue, rather than in their lower body. As they grow, these cells can become sick or die, and trigger an inflammatory response.
Researchers at Weill Cornell Medicine and Memorial Sloan Kettering Cancer Center warn the findings are key, since doctors tend to focus on obesity as the biggest risk factor for women.
And if they can identify a way to spot enlarged fat tissues in women’s breasts, the researchers believe they could drastically reduce the rate of breast cancer.
This research ‘increases our awareness of a potentially vulnerable population,’ said study lead author Dr. Neil Iyengar.
‘An alarming number of people may be at risk.’
Some women with a normal BMI may have an increased amount of body fat manifesting itself as enlarged adipocytes, increasing their risk of inflammation.
The enlarged sick or dying adipocytes release substances into fat tissue and blood, helping to recruit white blood cells called macrophages that cause inflammation.
The macrophages that envelop the dying adipocytes form crown-like structures that reflect inflammation.
While these macrophages eat the dead or sick adipocyte and clear it, the inflammatory process that is likely to contribute to cancer has already begun.
Specifically, the researchers found that breast inflammation was associated with an elevation of the enzyme aromatase.
Aromatase helps make estrogen, which can encourage the growth of some hormone-sensitive breast tumors.
In addition, they measured high levels of metabolic markers such as insulin and glucose in these patients.
‘It is similar to prediabetes, which is traditionally considered to be associated with overweight or obesity,’ Iyengar said. ‘We call it metabo-inflammation, which means there’s inflammation in the fat that has metabolic consequences even in these normal weight women.’
Prior research has shown that insulin and glucose increase breast cancer risk and shorten survival of women with the disease.
The researchers are now investigating how to use a dual-energy X-ray absorptiometry (DEXA) scan to assess body composition.
Previously, this technique was used to measure bone density.
Now, they hope they can use the X-ray to determine whether increased body fat or blood biomarkers might identify women with healthy BMIs who have underlying inflamed fat.
‘If we can develop a noninvasive test to identify those with inflamed breast fat, we will be positioned to reduce the risk of cancer,’ Dannenberg said.
Future research is needed to answer the question of why people with healthy BMIs develop this inflammatory state. ‘We don’t currently know the precise reasons,’ Iyengar said, ‘but it will be important to examine diet and activity levels to see if any patterns emerge and to ultimately develop effective cancer prevention and treatment strategies.’