Breast cancer diagnoses in the U.S. will grow by as much as 50 percent by 2030, according to a new analysis by researchers at the National Cancer Institute, part of the National Institutes of Health. The increase in cancer cases can be attributed to the aging of female baby boomers, a population of about 40 million American women born between 1946 and 1964 who also happen to be living longer, according to the researchers.