BMI linked to overall survival in locally advanced breast cancer

Issue: April 25, 2008

In women with locally advanced breast cancer, prognosis is worse among those with high BMI, compared with patients who are normal or underweight.

Researchers from University of Texas M.D. Anderson Cancer Center in Houston and Dubai Hospital in United Arab Emirates analyzed data from 602 patients with locally advanced breast cancer who were treated in prospective clinical trials. Patients were divided into three groups based on BMI: ≤24.9, normal/underweight; 25.0 to 29.9, overweight; ≥30, obese.

Eighty-two percent of patients had non-inflammatory locally advanced breast cancer; 18% had inflammatory locally advanced breast cancer. Compared with overweight and normal/underweight groups, those in the obese category had a higher incidence of inflammatory breast cancer (P=.01).

Compared with the normal/underweight population, overall survival and recurrence-free survival rates were worse for those in the obese or overweight categories who had locally advanced breast cancer (P=.001). The incidence of visceral recurrence was also higher among the overweight and obese groups. – by Stacey L. Adams

Clin Cancer Res. 2008;14:1718-1725.

This article is important because we are hoping to use any and all information available to help us understand the risks that women with breast cancer face. In other words, we want to make sure that we recognize all of the information that might be valuable in helping to understand how to take care of women with breast cancer.

In this instance, we have been informed that women who have a bad prognosis with breast cancer at the time of initial diagnosis will actually have a worse prognosis if they have a higher BMI. This information, therefore, helps us begin to categorize women within a conventional high-risk group — to categorize these women into relatively higher and relatively lower-risk groups with respect to their prognosis.

This study does not offer us a means to treat those women differently, but what it can do is suggest to us that if we recognize that there is a particular group of women at higher risk — women with those types of cancer who also have higher BMI — then in the future, we might be able to study that group of women specifically and look for better ways to treat them as a ‘high, high’ risk subset. We do this often in cancer medicine; we try to distinguish, even within a bad disease, those people whose disease is worse because those people in particular would benefit from having better therapies devised for them. This study, in and of itself, is interesting intellectually, but it will not lead anywhere unless researchers now take these women who have been defined as ‘high, high’ risk based on high BMI and try to do something for them.

That is why any study like this is done, really, it is not just the intellectual exercise but to help us understand who needs more help and then to begin to figure out ways to get them that help.

In medicine, we talk all the time to our patients about the value of maintaining a healthy weight. We know, for example, that the risk for diabetes is reduced if you maintain a healthy weight; we know that risk for cardiovascular disease, stroke, heart attack and high blood pressure will be reduced if you maintain a healthy weight. We believe that there are cancer risks that can be reduced by maintaining a healthy weight, and here is an example of that. There is a reasonably good foundation in this report to be able to say to women, ‘it is valuable to maintain a healthy weight because if you ever are so unfortunate as to develop breast cancer, by having a healthy weight at that time, you are going to make your prognosis better.’

So, I think this adds to the body of evidence that we need to make women aware that maintaining a healthy weight as a lifetime wellness strategy is a good thing to shoot for. I think the messages women get from medical professionals about maintaining a healthy weight are pretty widely disseminated in our culture and our medical care, but every opportunity we have to re-emphasize that and expand women’s understanding of that is worthwhile. So here is another instance in which it has been made clear that maintaining healthy body weight will be advantageous. This adds to the chorus calling for maintaining healthy body weight and it has a particular focus because it is a very important women’s health issue that a lot of women worry about.

– Donald W. Northfelt, MD

Associate Professor of Medicine, Mayo Clinic, Scottsdale, Ariz.