Image: Bar graph shows the change in detection method over time (1990-2011) for breast cancer cases in patients aged 75 years and older (n = 1162). Pt/PhysD = detection by patient or physician (Photo courtesy of the Radiological Society of North America).
Image: graph shows the change in stage over time (1990-2011) for breast cancer cases in patients aged 75 years and older (n = 1162) (Photo courtesy of the Radiological Society of North America).
Mammography-identified breast cancer is associated with a change to earlier-stage diagnosis in older women, which was shown to result in reducing the rate of more advanced, hard-to-treat cases, according to a new study.
The findings were published online August 4, 2014, in the journal Radiology.
Researchers noted that the study helps in backing regular mammography screening in women ages 75 and older.
The value of mammography screening in older women has been subject to much debate in recent years. The American Cancer Society recommends annual mammograms for women age 75 and older as long as they are in good health, while the US Preventive Services Task Force (USPSTF) does not recommend mammography screening in this age group, citing insufficient evidence to evaluate benefits and harms.
A lack of research is mainly responsible for the opposing recommendations, according to Judith A. Malmgren, PhD, affiliate assistant professor at the University of Washington’s School of Public Health and Community Medicine (Seattle, WA, USA). “There are no studies on women age 75 and older, despite the fact that they are at the highest risk for breast cancer,” she said.
Dr. Malmgren and her research partner, Henry Kaplan, MD, from the Swedish Cancer Institute (Seattle, WA, USA), recently looked at the impact of mammography detection on older women by studying data from an institutional registry that includes more than 14,000 breast cancer cases with 1,600 patients over age 75. Most mammography-detected cases were early stage, while physician- and patient-detected cancers were more likely to be advanced stage disease. Mammography-detected invasive breast cancer patients were more likely to be treated with lumpectomy and radiation and had fewer mastectomies and less chemotherapy than patient- or physician-detected cases.
Mammography detection was associated with a 97% five-year disease-specific invasive cancer survival rate, compared with 87% for patient- or physician-detected invasive tumors. “Mammography enables detection when breast cancer is at an early stage and is easier to treat with more tolerable options,” Dr. Malmgren said. “In this study, older women with mammography-detected invasive cancer had a 10% reduction in breast cancer disease-specific mortality after five years.”
The early detection provided by mammography is especially important in older women, Dr. Malmgren noted, because they cannot easily tolerate the chemotherapy that is typically used to treat more advanced breast tumors. “Longer life expectancies for women also increase the importance of early detection,” Dr. Malmgren said. “A 75-year-old woman today has a 13-year life expectancy. You only need five years of life expectancy to make mammography screening worthwhile.”
Dr. Malmgren noted that the potential costs of mammography, such as those associated with false-positive findings, are an important consideration when balancing screening benefits. However, she said that false-positive findings are less common in older women. “It’s easy to detect a cancer earlier in older women because breast density is not an issue,” Dr. Malmgren said. “And mammography is not expensive, so doing it every other year would not add a lot of cost to healthcare.”
The researchers hope that the study results help women and their physicians make better informed decisions about mammography, ultimately leading to lower mortality rates. “Breast cancer survival in younger women has improved dramatically over last 20 years, but that improvement has not been seen in older women,” Dr. Malmgren said.
University of Washington’s School of Public Health and Community Medicine