Screening Mammography Drops After Age 70 But Invasive Breast Cancer Does Not

MedicalResearch.com Interview with:
Pamela Vacek, PhD
Research Assistant Professor
Department of Pathology
Medical Biostatistics Unit, College of Medicine
University of Vermont, Burlingon, Vermont

Medical Research: What is the background for this study? What are the main findings?

Dr. Vacek: Clinical trials to evaluate the effectiveness of screening mammography have focused primarily on women under age 70 and, consequently, its benefit for older women is uncertain. However, many believe that the benefit of screening mammography diminishes as women age and acquire other health problems, because they are less likely to live long enough for any detected breast cancer to have a clinical impact. To gain insight into this, we followed approximately 20,000 women aged 70 and older for an average of 10 years to examine their mammography use, cancer detection and survival.

We found that screening mammography use declined steadily (9% per year) after age 70, but this was not accompanied by decline in the incidence of invasive breast cancer. Hence, as the women aged breast cancer was more likely to be detected clinically than by screening. The clinically detected tumors were significantly larger and of more advance stage and were associated with poorer overall survival, for all but the oldest and most infirm women. We also found that the use of breast conserving surgery as the only treatment for early stage cancer increased markedly with age and was associated with shorter survival compared to women receiving radiation or mastectomy.

Medical Research: What should clinicians and patients take away from your report?

Dr. Vacek: These results raise questions about the advisability of discontinuing screening mammography solely on the basis of a woman’s age and health problems. If an older patient would be willing and able to receive adequate treatment for breast cancer, she is likely to benefit from continued screening.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Vacek: Although the benefits of screening mammography for older women can only be definitely established by a clinical trial, other types of research may help determine its utility. We did not have information about cause of death for all the women in our study, so only looked at the impact of a breast cancer diagnosis on overall survival. A more detailed study of mortality after diagnosis would help clarify how breast cancer impacts survival older women. More information is also needed about the factors influencing the treatment choice and its impact, because screening mammography can only be of benefit if a woman receives effective treatment when diagnosed with breast cancer.

Citation:

A Prospective Study of the Use and Effects of Screening Mammography in Women Aged 70 and Older

Pamela M. Vacek PhD and Joan M. Skelly MS1

J Am Geriatr Soc 2014.
Article first published online: 23 DEC 2014
DOI: 10.1111/jgs.13184