Harms Outweigh Benefits for Women Aged 70 and Over in National Breast Cancer Screening Programs
Extending national breast cancer screening programs to women over the age of 70 does not result in a decrease in the number of cancers detected at advanced stages, according to new research from The Netherlands. Instead, researchers told attendees at the 9th European Breast Cancer Conference that their findings suggest extending screening programs to older women results in a large proportion of women being overtreated and at risk from the harmful effects of such treatment; these women were more likely to die from other causes than from any tumors detected in early stages of growth.
Gerrit-Jan Liefers, MD, PhD, a surgical oncologist and head of the geriatric oncology research group at Leiden University Medical Centre, said, “For a screening program to be effective, one would expect that the incidence of early-stage breast cancer would increase while the incidence of advanced-stage cancer would decrease because any cancer would have been detected at an earlier stage.
“However, when we investigated the effect of extending the screening program in The Netherlands from age 69 to 75, we found that it had not led to a decrease in the rate of advanced breast cancers detected, while the numbers of early-stage tumors strongly increased. This implies that the effect of screening in elderly women is limited and leads to a large proportion of overdiagnosis,” he said.
Study Details
The Netherlands breast cancer screening program was extended in 1998 to include women up to the age of 75. Dr. Liefers and his colleagues looked at results from The Netherlands Cancer Registry for 25,414 women aged 70 to 75 who were diagnosed with breast cancer between 1995 and 2011.
They found that after the extension of the upper age limit, the incidence of early-stage breast cancer (stages 0, I, and II) increased significantly from 260 cases per 100,000 women in 1995 to up to 382 cases per 100,000 women in 2011. Meanwhile, the number of advanced-stage breast cancers (stages III and IV) did not change significantly: In 1995 there were 59 cases detected per 100,000 women compared to 53 per 100,000 in 2011.
“In these more elderly women, other, competing causes of death are of major importance. Although [locoregional treatment] is generally considered to be low risk, we have previously demonstrated that the proportion of patients who develop postoperative complications strongly increases with age and increasing numbers of other diseases or conditions that they may have,” Dr. Liefers said.
“Furthermore, older patients are at risk from the adverse side effects of adjuvant treatments such as hormone therapy or chemotherapy,” he continued. “Therefore, screening could result in overtreatment and consequently in decreased quality of life and ability to function in older breast cancer patients, without lowering the incidence of advanced-stage breast cancer or deaths from the disease.”
More Personalized Approach to Screening Needed
The proportion of breast cancer patients who are elderly will continue to increase in the coming decades, and Dr. Liefers noted that “the additional costs of treating overdiagnosed tumors could result in a tremendous increase in health expenditure, while no actual health benefits are being obtained.” He proposed that studies investigating breast cancer treatment strategies rather than screening should be prioritized in this population. “Breast cancer treatment in older patients is mostly not evidence-based due to poor inclusion of older patients in clinical trials,” he said.
“Currently, the NHS Breast Cancer Screening Programme in the UK is undertaking a large randomized controlled trial in patients aged 71 to 73 in order to evaluate the effects of screening on breast cancer incidence and mortality. Until results of this trial become available, we suggest that the decision to participate in the screening programs should be personalized, for instance in discussions with primary care physicians, and be based on remaining life expectancy, the patients’ ability to function in everyday life, and their preferences,” he said.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
