Study Suggests More Breast Cancer Screening

Breast cancer screening frequency affected lymph node positivity

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) In 2009, the US Preventive Services Task Force (USPSTF) recommended that women between the ages of 50 and 74 have breast cancer screenings every two years. A new study has challenged these guidelines.

This study found that women who had more frequent breast cancer screenings were more likely to have less advanced disease at diagnosis than women whose screenings took place at longer intervals.

Screening mammography performed at intervals of less than 18 months reduced the likelihood of the cancer spreading from the breast to the lymph nodes, this study discovered.

"Establish a breast cancer screening schedule based on your personal risk factors."

Researchers, led by Lilian Wang, MD, assistant professor of radiology at Northwestern University/Feinberg School of Medicine in Chicago, Ill, looked at what would happen if women followed the USPSTF guidelines.

Dr. Wang’s team was measuring effectiveness by assessing lymph node involvement seen in women diagnosed with breast cancer after being screened at various time intervals.

The USPSTF screening guidelines are the most lax. The American Cancer Center, the Society of Breast Imaging and American College of Radiology all recommend that annual screening mammography begin at age 40.

For this study, the researchers looked back at breast cancers detected by screenings between 2007 and 2010. The 332 women in the study were divided into three groups based on the time intervals between mammograms:

  • less than 18 months (207 women)
  • 18 months to three years (73 women)
  • more than three years (52 women)

There were no major differences in breast cancer risk factors (age, breast density, family history of breast cancer and breast density) among the groups. Also, the research team found no statistical differences in the stage of or size of cancers detected.

The big differences were seen in how many patients had cancer that had spread to the lymph nodes, which is generally the first place this cancer goes when it metastasizes (spreads) beyond the breast.

Cancer was found in the lymph nodes of 8.7 percent of the women who were screened at intervals of less than 18 months, compared to 20.5 percent of women screened between 18 months and three years and 15.4 percent of the women who were screened at over three year intervals.

Dr. Wang, who advocates for annual screening mammography to begin at age 40, said in a statement, "Our study shows that screening mammography performed at an interval of less than 1.5 years reduces the rate of lymph node positivity, thereby improving patient prognosis."

Adam M. Brufsky, MD, PhD, professor of medicine at the University of Pittsburgh School of Medicine, told dailyRx News, "This is an interesting and provocative study, on a small number of patients. I am not sure at this point that it will change anything, since many of us screen women in these age groups yearly."

Findings from this study were presented at the annual meeting of the Radiological Society of North America (RSNA). It should be noted that all research is considered preliminary before it is published in a peer-reviewed journal

One of the authors reported having financial relationships with several companies that manufacture imaging equipment used for breast cancer screening. No other conflicts of interest were reported.

Review Date: 
December 3, 2013
Last Updated:
December 30, 2013