A paper published yesterday in the Journal of the American Medical Association describes a small but statistically significant increase in the incidence of breast cancer with remote metastases (breast cancer that has spread to other parts of the body, including the bones, brain and lungs) at first diagnosis for women aged 25 to 39 years.
This statistical study examined the incidence of breast cancer in women in the U.S. from 1976 to 2009. The increase in remote metastases at first diagnosis was not seen in older women. There was also no increase in the incidence of local breast cancer (confined to the breast only) or regional breast cancer (cancer that has spread to adjacent organs like lymph nodes or the chest wall) diagnoses in younger women.
There's been a lot of commentary on this paper already, some of which has been potentially misleading. Our friends at the Young Survival Coalition have published an in-depth and thoughtful blog post on this paper that puts this new data into context.
There is a need for more research to confirm this finding—something the paper's authors agree needs to be done.
If this increase is confirmed, we need to find out how such an increase could occur within a single generation of women. In particular, we want to know what's causing metastatic breast cancer—including potential environmental exposures—among women of all ages.