Behaviour within a Clinical Trial and Implications for Mammography Guidelines.

Area of Science:

• Medical Screening
• Public Health Policy
• Oncology

Background:

• Mammography guidelines are evolving due to concerns about overdiagnosis, where asymptomatic breast cancers are detected that may never cause harm.
• Current US guidelines for women aged 40-49 recommend mammograms based on personal choice rather than a strong recommendation, reflecting these concerns.

Purpose of the Study:

• To evaluate the effectiveness of US mammography guidelines in targeting women.
• To assess whether current guidelines inadvertently lead to higher overdiagnosis rates in specific populations.

Main Methods:

• Analysis of mammography behavior within a long-term clinical trial cohort.
• Examination of the relationship between likelihood of receiving mammograms and overdiagnosis rates.
• Stratification of overdiagnosis by participant health status and socioeconomic factors.

Main Results:

• Women more likely to undergo mammograms tend to be healthier and have higher socioeconomic status.
• Overdiagnosis rates were at least 3.5 times higher over 20 years for women most likely to receive mammograms.
• Approximately 36% of cancers detected in this high-screening group were overdiagnosed.

Conclusions:

• US mammography guidelines may disproportionately encourage screening among healthier women who are at a higher risk of overdiagnosis.
• The findings suggest a potential misalignment between current US guidelines and the goal of minimizing overdiagnosis.
• International guidelines may offer alternative approaches to mammography recommendations.