The incidence of breast cancer is expected to remain constant at approximately 200 cancers per 100,000 woman-years through 2016, according to an article published online July 13 in the Journal of the National Cancer Institute.
However, lead author Dr. William Anderson, from the National Cancer Institute's Division of Cancer Epidemiology and Genetics' Biostatistics Branch, and colleagues expect the rates of estrogen-receptor (ER) positive and negative breast cancers to change: ER-positive cancers are projected to increase to 5.3%, and ER-negative cancers are slated to decrease 11.4% from 2008 through 2016.
The research team developed its conclusions after analyzing data from the Surveillance, Epidemiology, and End Results Program (SEER) database of 588,720 women with invasive breast cancer registered from 1980 through 2008. Data represented more than 471 million woman-years of follow-up.
While breast cancer rates peaked in 1999 at an incidence of 232 cancers per 100,000 woman-years, the rate of ER-positive breast cancer increased 1.17% per year between 1992 and 2008 among younger women ages 30 to 49. However, in this same age group, the rate of ER-negative breast cancer, one of the most difficult types of breast cancer to treat, decreased 2.42% per year. It is expected to continue to do so at an annual rate of 2% through 2016, according to the researchers.
Anderson and colleagues developed an imputation model to correct for missing ER data from 1980 through 1989, a period of time when these data were not collected.
