Current breast cancer cases are made up of 20% of newly diagnosed breast cancers, which is the early stage. This is the time when the cancer is limited to cells that are found in the ducts or lobules of a woman’s breast.
However, even though there were nearly 2.5 million breast cancer survivors in the USA in 2005, researchers at the University of Wisconsin-Madison, Brian L. Sprague and Amy Trentham-Dietz, have taken notice of the fact that breast cancer in situ survivor numbers are not known and documented this research in a report that was published in the Journal of the American Medical Association.
Executive director of the advocacy group Breast Cancer Action, Barbara A. Brenner, explains:
“A lot, but not all, of the increase in in situ breast cancers is a consequence of screening for breast cancer. This is leading to a lot of over-diagnosis, and hence, over-treatment.”
Sprague and Trentham-Dietz used data retrieved from the Surveillance, Epidemiology and End Results registries, to approximately calculate the number of surviving women with breast cancer in situ and based on that they were then able to calculate the development over the next few years.
Their research indicated that 610,171 of women that were diagnosed with breast cancer in situ during the past 30 years were still alive in 2005.
Ductal and lobular are the two different types of breast cancer in situ; because of this, women who have either of these types of breast cancers are four times more likely to develop invasive breast cancer compared with the general female population in the USA, as noted by the researchers.
Sadly, there is no scientific method in existence today that can help in determining which women will actually develop invasive breast cancer. So, these women are given the same type of treatment as women who have localized invasive cancer which results in a lower life expectancy.
Brenner says, “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. So, knowing you have either condition just puts you in a world of ‘What to do now.'”
In comparison to women who were diagnosed with lobular breast cancer in situ, women with ductal breast cancer in situ were actually five times more likely to become breast cancer survivors, according to Sprague and Trentham-Dietz.
The Wisconsin researchers also noted that out of the different racial groups, white women were more prone to being breast cancer survivors than any other female race.
The best results of their research indicated that the survival statistics for women diagnosed with breast cancer, actually improved and increased over a time. In 1975, 21,654 women who were diagnosed with breast cancer, were still alive and well in the year 2005. The research showed that the number of breast cancer survivors quadrupled for those women were diagnosed in 1985, and the number doubled again for women who were diagnosed with breast cancer in 1995.
In the report, Sprague and Trentham-Dietz wrote:
“Assuming constant incidence and survival rates, the estimated prevalence of breast cancer in situ will exceed 1 million cases by 2016.”
Sprague and Trentham-Dietz believe that the increase in the breast cancer survival rate is most probably due to improved breast cancer screening which would then lead to an early diagnosis. Breast cancer in situ, prior to 1995, consisted of about 4% of all breast cancer diagnosed during that year.
“If there is an underlying increase in in situ breast cancers that is not the result of screening, and there seems to be, we should be looking for the causes, very likely environmental, of that increase,” Brenner said.
The Wisconsin researchers, Sprague and Trentham-Dietz, both agree that in situ breast cancer is a vastly unknown diagnosis and, as such, there is still plenty to learn about this particular type of breast cancer.
Sprague and Trentham-Dietz wrote in their report:
“Current epidemiologic evidence regarding predictors of subsequent invasive breast cancer after breast cancer in situ is limited. Guidelines are necessary to help the increasing number of breast cancer in situ survivors choose the best treatment and lifestyle strategies while still maintaining high quality of life.”
Photo Credit: Amy Guth