Large Portion of Late-Stage Breast Cancers Associated With Absence of Screening
Increasing mammography screening rates and investing in research
to improve breast cancer detection technologies should be top priorities,
according to authors of a study published in the October 20, 2004,
Journal of the National Cancer Institute*.
As many as 92 percent of late-stage breast cancer cases in the United
States could be diagnosed and treated earlier, when there is greater
likelihood of effective treatment, if the healthcare system focused
on recruiting women who have not been recently screened, and if
early detection techniques could be improved to more accurately
detect cancer. The study was conducted by researchers at the National
Cancer Institute, part of the National Institutes of Health, and
the Cancer Research Network (CRN), a consortium of integrated health
plans.
Study results indicated that not having had a screening mammogram
for one to three years prior to diagnosis was associated with 52
percent of late-stage breast cancer cases. The authors state that
to improve breast cancer outcomes, priority should be placed on
reaching unscreened women and encouraging them to have mammograms
especially older, unmarried, less educated, and/or low income
women, whom they found were less likely to have been screened. “The
good news is that there is a lot known about how to reach women
who have never been screened or who fail to get regular mammograms,”
said Stephen Taplin, M.D., M.P.H., a senior scientist in NCI’s
Division of Cancer Control and Population Sciences and lead author
of the study. “The challenge is to put this knowledge into
practice.”
The study was based on a review of all medical care received by
2,694 women during the three years prior to their breast cancer
diagnosis. Researchers reviewed medical charts and records of women
in seven integrated healthcare plans across the United States. The
plans offer specialty and primary care within the same system, and
serve 1.5 million women over age 50. All offer breast cancer screening
mammograms at no or low cost. When the study began in 1999, 71 percent
to 81 percent of these women had had mammograms. “Few women
in a regularly screened population should be diagnosed with late-stage
breast cancer because, in theory, screening should identify cancers
before they progress to the late stage,” explained Taplin.
“However, there were still cases of late-stage breast cancer
in this population.”
Taplin previously worked at Group Health Cooperative in Seattle,
Wash., where he led a team of investigators who were part of the
NCI-funded CRN. Taplin and colleagues at participating health plans
divided the patients in the study into two groups based on the stage
at which their cancer was diagnosed. Women whose cancer had spread
throughout the body or who had tumors three centimeters or larger
made up one group, while women who were diagnosed in the early stages
of breast cancer, when their tumors were smaller, made up the second
group. The two groups, which each contained 1,347 women, were matched
for age and type of health plan.
A key finding was that women who had not been screened one to three
years prior to diagnosis were more than twice as likely to have
late-stage breast cancer. This finding illustrates an important
reason for receiving regular mammograms: to increase the chance
of catching breast cancer early. However, a second finding showed
that better screening tests need to be developed. Almost 40 percent
of women with late-stage breast cancer had a negative mammogram
one to three years before their diagnosis.
“These findings show that improvements in both the implementation
of mammography and in the methods we use for early detection could
reduce late-stage disease,” said Taplin. The researchers also
found that women were less likely to have been screened if they
were Hispanic, unmarried, or had no family history of breast cancer.
NCI Director Andrew von Eschenbach, M.D., said, “This study
helps us identify research priorities for breast cancer screening.
To eliminate the suffering and death due to cancer, weneed to improve delivery to reach women who don’t receive
regular mammograms, improve the interpretation of mammography, and
find new screening tests. All these things are important to achieve
national goals.”
For more information about cancer, visit the NCI Web site at
http://www.cancer.gov or call
NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).
* Taplin SH, Ichikawa L, Yood MU, Manos MM,
Geiger AM, Weinmann S, et al. Reason for Late-Stage Breast Cancer:
Absence of Screening or Detection, or Breakdown in Follow-up? Journal
of the National Cancer Institute 2004;96:1518-27. |