Researchers at the National Cancer Institute reported on Monday that they believe that the number of breast cancers suffered by American women will increase by about 50 percent by 2030.
Breast cancers are already the most common form of cancer found in the United States, with 283,000 diagnosed cases in 2011. That number, however, is predicted to rise to about 441,000 by 2030according to Philip Rosenberg, a senior investigator in the division of cancer epidemiology and genetics at the National Cancer Institute.
This latest information was released ahead of a presentation by Rosenber at the annual meeting of the American Association for Cancer Research. The sharp increase is expected to be fueled by an increase in tumors that are receptive to the estrogen hormone, also known as ER-positive breast cancers and by the total number of cancers in women over the age of 70, Rosenberg said. The total includes both invasive and non-invasive forms of breast cancer.
The proportion of invasive estrogen-receptor-positive cancers was expected to hold steady at 63%, while that of estrogen-receptor-positive cancers that had not spread to other parts of the body was expected to increase, from 19% to 29%.
While overall breast cancer rates will increase, it isn't all bad news. Rosenberg believes that there will be a decline in the number of tumors that are not receptive to estrogen. These types of tumors are more difficult to treat because they do not respond to endocrine therapy. These types of tumors are expected to decrease from about 17 percent of all tumors to about 9 percent, for reasons that are not clear, according to researchers.
Half of the increase also includes carcinoma in situ. These are smaller, earlier cancers, and some experts argue that they shouldn't be considered cancers at all. Some doctors, in fact, believe that women are actually being over treated for these types of cancers as they would have never grown or done them harm in the first place.
"Although breast cancer overall is going to increase, different subtypes of breast cancer are moving in different directions and on different trajectories," Rosenberg said in a statement.
Researchers have also predicted a change in age distribution of breast cancers, with the number of cancers ocurring in women ages 70 - 84 expected to increase from 24% to 35% and that in women ages 50 - 69 was expected to fall from 55% to 44%.
The team said it embarked on this study in an effort to help oncologists define a "proactive road map" for both treatment and prevention in the future.
