More young women in the United States apparently are being diagnosed with advanced breast cancer than in the past, a trend not seen among older women, according to a study appearing today in JAMA.
Although the numbers remain small, the finding is a concern, because breast cancer in young women tends to be more aggressive disease and is associated with lower survival rates than breast cancer in older women. In 1976, the rate of diagnosis of advanced breast cancer (cancer that has metastasized to parts of the body away from the breast such as the brain, lungs, or bones) among women aged 25 to 39 years was 1.53 cases per 100 000 women; by 2009, the rate had climbed to 2.90 cases per 100 000, an annual increase of 2.07%. The study is based on data from 3 US National Cancer Institute Surveillance, Epidemiology, and End Results databases spanning 1973-2009, 1992-2009, and 2000-2009.
Lead author Rebecca H. Johnson, MD, of Seattle Children’s Hospital and the University of Washington, discusses her team’s findings:
news@JAMA: Why did you want to see if the incidence of breast cancer in young women was increasing?
Dr Johnson: I’d had that question in mind for years. I was diagnosed with breast cancer when I was 27. And after that, I’d meet young women patients with breast cancer and it seemed like a lot of friends of friends had breast cancer. And yet the literature kept saying that breast cancer in young women was rare.
news@JAMA: And you found the incidence of advanced breast cancer in young women has increased.
Dr Johnson: We found that after analyzing women of all ages and breast cancer stage at diagnosis, there was a significant increase of metastatic breast cancer in young women and only young women. The increase was most prominent in the youngest cohort, those aged 25 to 34, and decreased in each age cohort, such that there was no significant increase in women over age 54. And we found the rate of increase increased over time.
news@JAMA: Any thoughts as to why advanced breast cancer has increased in younger women?
Dr Johnson: What we studied doesn’t address causality, so the next steps for researchers will be to examine potential causes for this trend and look at etiologies. Given there’s such a change over a short amount of time, we may find modifiable risk factors or potentially toxic exposures that are fueling this increase.
news@JAMA: Did you find a similar increase in death rates from breast cancer in young women?
Dr Johnson: The death rate in this age cohort, young women with metastatic breast cancer, has remained fairly stable in the 34-year interval we studied, suggesting better medical strategies and supportive care strategies.
news@JAMA: Do your findings make a case of general population mammography screening for women under age 50 years?
Dr Johnson: What the average young woman should not do is go get a mammogram, because while on a population level we saw a statistically significant increase, it’s not a large increase of risk for an individual. One thing that has the potential to affect young women’s survival is earlier detection—seeing a physician if you find a lump instead of ignoring it.