A new study in the Journal of the American Medical Association finds a small but significant increase in advanced breast cancer among women in their 20's and 30's. Researchers found the rate has gone up each year since 1976.
When the study started in the mid 70's about 250 younger women developed breast cancer every year. By 2009, the number has risen to more than 800 a year.
The greatest increase occurred in 25- to 34-year-old women. Progressively smaller increases occurred in older women by 5-year age intervals and no statistically significant incidence increase occurred in any group 55 years or older.
Young women with breast cancer tend to have more aggressive forms of the disease than older women and have lower survival rates.
Experts say younger women usually don't know something is wrong until they can actually feel a lump - a sign that the tumor is advanced. Researchers say more studies need to be done to figure out why the numbers are going up.
The lead researcher says she's not recommending that women be screened at an earlier age. Every year in the United States, 11,000 women under 40 are diagnosed with breast cancer