Obesity may impact breast cancer survival in younger women

Karen Hackett has lost 30 pounds since she was diagnosed with breast cancer two years ago.

"I've made exercise become a priority," Hackett told CBS News. "It's just part of my day. I try to go sometime around the lunchtime hour and if I don't, I can go in the evening."

Research finds when it comes to beating breast cancer, Hackett's regular visits to the gym may be an important addition to the medical treatments she's received to beat the disease. A new study found pre- or peri-menopausal women with hormone-sensitive breast cancer may have poorer health outcomes if they are obese. The study by researchers at Oxford University was presented this week at the American Society of Clinical Oncology's 50th annual meeting.

"That's the novel finding here," Dr. Clifford Hudis, an oncologist at Memorial Sloan Kettering Cancer Center told CBS News. "We used to think that this association was really seen primarily in older women, here it's being seen in young women."

The study, a retrospective analysis of data from 70 trials and 80,000 patients, focused on women who were already diagnosed with breast cancer. The researchers did not find the same correlation between obesity and breast cancer outcome among older, post- menopausal patients.

Much has been made about the link between obesity and breast cancer -- though scientists are still trying to make sense of the correlation.

Some research has shown fat cells can encourage estrogen production in the body, which can increase the likelihood of developing estrogen-receptor positive breast cancer. This type of breast cancer receives signals from the female hormone that promotes its growth, and it is one of the most commonly diagnosed.

Additionally, scientists say obesity increases inflammation in the body, which allows cancer cells to thrive.

It's unclear if weight loss after diagnosis can improve the health outcome. However, some research is finding any weight loss can have significant impact on breast cancer risk and survival.

One study published in the Journal of Clinical Oncology found dropping a few pounds could lower a woman's likelihood for developing the disease. In the study of 439 obese women aged 50 to 75, those who dieted, exercised and lost significant weight also reduced their levels of the hormones commonly associated with breast cancer. That study found even a 5 percent weight loss decreased one's breast cancer risk by as much as 22 percent.