Pepper Schedin, PHD; University of Colorado Health Science Center; Synergistic Idea Award:

Our recent award from the Department of Defense Breast Cancer Program is to study pregnancy associated breast cancer, and this is really a new area and a novel area of research for the breast cancer community. And so the funding is really critically important because it is so novel.

So what we are studying in normal mammogram biology was how the gland remodels/restructures after pregnancy when it's in its fully differentiated state and goes back to the pre-pregnant state. So from a milk-producing state to the normal, what we consider the normal state. And in that process a full 90 percent of the mammary epithelial cells die by a programmed cell death process. That's normal, it's physiologic, but it's absolutely catastrophic from a biological perspective. It's more tissue remodeling than you would see even in wound healing - in dramatic wound healing. But it's a normal process. And we were studying this because we thought it might be one reason why pregnancy was protective. Because if there was a cancer cell present and it also received those cell death signals you would remove the cancer. So we were studying it from that perspective, but what we found was that the more we studied the way that this involution process occurs, the more similar to wound healing it was. So while it's a normal process, it uses some of the exact same programs that the body uses to heal wounds. And that was the "ah-ha" moment, because its also known that cancer cells are promoted by wound healing environments and so we reasoned that this might be a risk factor for women who have early stage disease. So then we went back into the literature and found out that sure enough buried in the literature is evidence that pregnancy is both protective and promotional. So the protection is long term. Women are less likely to develop breast cancer when they're older if they had an early pregnancy. But the promotion is immediate, so if you have a pregnancy, you are more likely to be diagnosed with breast cancer; and if you diagnosed with breast cancer shortly after pregnancy, you are more likely, twice as likely, to die of that disease.

This is how disease affects women as they age, and if you look at the women in the reproductive years, it looks like this is not a big problem -- when you look at the data this way. So what I did was I reevaluated this statistics by looking at simply the number of women that walk into a clinic by age and whether they are diagnosed with breast cancer. So this is the same population as here but now you are looking at the number of women and what you see is that curve shifts far to the left. So these are actually women in their reproductive years that are being diagnosed with breast cancer. And the reason this curve shifts so dramatically to the left is because our population is skewed so strongly to young women. So we underestimate the number of cases of young women's breast cancer based on this depiction. So we would like to expand the definition, which means that the number of women who would be potentially impacted by a pregnancy in terms of how they might be treated for breast cancer is really much broader than currently appreciated. Much, much bigger group of women than is currently appreciated.

If we look at U.S. statistics and use 35 years of age as our cut-off for age when you may have a pregnancy, which is not getting to be an unusual cut-off, we find that we can estimate 30,000 cases a year in the U.S. with breast cancer complicated by a recent pregnancy and again I emphasis the population. These are women with young children, the burden on the family is huge. So it's a special population.