More Women Surviving After Early Breast Cancer

Aug. 26 -- TUESDAY, Aug. 25 (HealthDay News) -- The first accounting of women with breast cancer in situ in the United States finds that in 2005 there were 610,171 survivors, but that by 2016 that number is expected to increase to more than 1 million.

Breast cancer in situ now accounts for 20 percent of newly diagnosed breast cancers. It is the early stage of the disease, when it is still confined to the layer of cells in the ducts or lobules of the breasts.

University of Wisconsin-Madison researchers Brian L. Sprague and Amy Trentham-Dietz noted that while there were 2.5 million breast cancer survivors in the United States in 2005, the number of breast cancer in situ survivors was unknown. Their research is reported in the Aug. 26 issue of the Journal of the American Medical Association.

"A lot, but not all, of the increase in in situ breast cancers is a consequence of screening for breast cancer," explained Barbara A. Brenner, executive director of the advocacy group Breast Cancer Action. "This is leading to a lot of over-diagnosis, and hence, over-treatment."

Using data from the Surveillance, Epidemiology and End Results registries, the Wisconsin researchers were able to estimate the number of surviving women with breast cancer in situ and predict the trend over the next decade.

They found that in 2005, 610,171 of the women diagnosed with breast cancer in situ in the previous 30 years were alive.

There are two types of breast cancer in situ: ductal and lobular. These women are four times more likely to develop invasive breast cancer compared with the general population, the researchers noted.

Since there is no way to predict which women will develop invasive breast cancer, they often have the same treatment as women with localized invasive cancer with similar reductions in quality of life.

"There is currently no way to tell women with ductal breast cancer in situ or lobular breast cancer in situ whether their condition, untreated, will develop into invasive disease," Brennen said. "So, knowing you have either condition just puts you in a world of 'What to do now.'"