Breast cancer screening in older women has been a much discussed topic in the last several years. In 2009, the U.S. Preventive Services Task Force (USPSTF) recommended that mammograms shouldn’t be encouraged in women ages 75 and older because they might not benefit from the screenings. The USPSTF made this recommendation because no research had shown that these women would benefit from regular mammograms. The USPSTF also recommended that breast cancer screening should start at age 50 instead of 40 and that mammograms should be done every other year instead of every year.
Several medical organizations and advocacy groups, including the American Cancer Society and Breastcancer.org, didn’t agree with the USPSTF conclusions and ignored the recommendations. The recommendations were very controversial and were not widely adopted by doctors.
A large study has found that women benefit from screening mammograms until about age 90.
The research was presented on Nov. 28, 2016 at the Radiological Society of North America 2016 Annual Meeting. Read the abstract of "Current Era Screening Mammography Outcomes from the National Mammography Database, Involving Nearly 7 Million Examinations.”
"All prior randomized, controlled trials excluded women older than 75, limiting available data to small observational studies," said Cindy S. Lee, M.D., assistant professor in residence at the University of California, San Francisco, who presented the study. "There has been a lot of controversy, debate, and conversation regarding the different breast cancer screening guidelines, even among major national organizations, over the past few years."
To learn how much older women benefited from mammograms, the researchers analyzed data from more than 5.6 million screening mammograms done from January 2008 and December 2014 in 150 centers in 31 states. The information was in the National Mammography Database.
The researchers looked at the women’s demographics, screening mammography results, and biopsy results.
Information from more than 2.5 million women older than 40 were sorted into groups by age in 5-year intervals.
The researchers judged the effectiveness of screening mammograms in each age group by looking at four factors:
- cancer detection rate
- recall rate (percentage of women called back for follow-up testing)
- positive predictive value for biopsy recommended (percentage of cancers found when biopsy was recommended or done after a screening mammogram)
- biopsy rate
Effective screening has a higher cancer detection rate, a higher positive predictive value for biopsy, a higher biopsy rate, and a lower recall rate.
- the cancer detection rate was 3.74 per 1,000 women screened
- the recall rate was 10%
- the positive predictive value of biopsy was 20%
- the biopsy rate was 29%
As the age groups went from 40 to 90, there was a gradual increase in the cancer detection rate, the positive predictive value of biopsy, and biopsy rate, and a downward trend in recall rates.
"We are finding more cancers with increasing age," Lee said in an interview, which makes sense because risk rises with age. "We are doing better at catching them. We have decreased the recall rate. We are calling back fewer women for additional testing, but are finding more cancers. There is no clear age cut-off point to determine when to stop screening."
Nearly all experts would agree that annual screening doesn’t make sense for an older woman who wouldn’t want to be treated for breast cancer because of personal preferences or other health issues. Still, many women age 75 and older are in reasonably good health and would want to be treated should they be diagnosed with breast cancer. And it’s important to know that this study does not mean that women older than 90 should not get a mammogram if they want one.
Breastcancer.org believes that the importance of diagnosing breast cancer early, when it’s most treatable, doesn’t get any less important as a woman gets older. Regular screening mammograms make sense for any woman age 75 and older who would want to be treated for breast cancer should she be diagnosed.
For more information, visit the Breastcancer.org Mammograms page.