Over 240,000 women are projected to receive a breast cancer diagnosis in the United States this year, and many of them will likely commence treatment promptly. However, recent research suggests that this approach might not always be the best course of action.
A new study reveals that breast cancer is frequently overdiagnosed in women aged 70 to 85, leading to unnecessary distress and aggressive treatments like surgery and chemotherapy that do not enhance their quality of life.
Dr. Ilana Richman, the lead author of the study and an assistant professor of medicine at the Yale School of Medicine, explained, “Overdiagnosis occurs when we detect breast cancers during screenings that would never have caused symptoms. This can happen when the cancers grow very slowly or if the person’s life expectancy is short.”
Reassessing Screening Strategies for Older Patients
Published in the Annals of Internal Medicine, this research underscores the importance of reevaluating screening methods and having well-informed conversations with patients.
While mammography is a widely used method for screening breast cancer, the study identifies a research gap when it comes to older women. Individuals aged 74 and above have often been excluded from large randomized screening trials, leaving uncertainties about the complete range of screening advantages and potential downsides.
The study, which involved 54,635 women aged 70 and older, examined breast cancer diagnoses and associated mortality rates over a 15-year follow-up period.
The findings suggest a substantial likelihood of overdiagnosis among older women. Specifically, approximately 31 percent of women aged 70 to 74 were likely overdiagnosed, along with 47 percent of those aged 75 to 84, and 54 percent of those aged 85 and older.
“This discovery emphasizes the need for improved tools that can identify which women would benefit from screening and which breast cancers are unlikely to progress, enabling us to avoid unnecessary treatments,” Dr. Richman pointed out.
The Dilemma of Overdiagnosis: Weighing Risks Versus Benefits
Translating the findings of this study into clinical practice faces two main challenges.
Firstly, striking a balance between the risks of overdiagnosis and the potential benefits of screening is intricate, given the existing uncertainties in the data, as per Dr. Richman.
Secondly, discussing the concept of overdiagnosis with patients presents communication challenges. It’s an abstract and unfamiliar notion that can’t be directly observed, making it challenging to integrate into busy clinic visits.
To address these issues, tools are needed to support patient-provider conversations and provide personalized information to women, Dr. Richman said. “[This] can help ensure that decisions about screening are concordant with our patients’ values.”
Breast cancer rates peak among women aged 70 to 74, according to the American Cancer Society. The risk decreases as women age into their 80s, partly because women tend to die from other causes instead, such as heart disease or other cancers.
Improved Detection Comes at a Cost of Surging Overdiagnosis Rates
Recent technological advancements—such as three-dimensional mammography, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PT) scans—have increased detection rates.
However, the sensitivity of these advanced images leads them to detect a wide range of abnormalities, including noncancerous lesions, slow-growing tumors, and lesions that may spontaneously regress.
The introduction of screening programs has led to sharp rises in invasive breast cancer diagnoses—even for abnormalities that typically naturally regress.
In the present paradigm, once cancer is detected, it’s typically treated aggressively with surgery, radiation, or chemotherapy. However, this amplified volume of treatment increases the risks of complications and financial burden, especially for older patients. It also unnecessarily exposes women to repeated radiation from mammograms.
A mammogram is essentially an X-ray, a form of ionizing radiation that has raised concerns due to its risk of causing radiation-induced breast cancer.
The central dilemma is that increased detection doesn’t equate to improved outcomes. More research is needed to determine appropriate screening guidelines, especially for women over 75. The goal is to identify cancers destined to progress while avoiding overtreatment of regressive or indolent lesions.
In May, the U.S. Preventive Services Task Force, an independent panel of experts that provides screening guidelines for clinicians, issued new recommendations. The experts advised starting routine breast cancer screening at age 40 instead of 50. However, they also acknowledged the need for further research on screening benefits and harms to determine appropriate guidelines for women over 75.