Overview

• A University of Manchester study presented at ECO 2025 analyzed 48,417 women over 6.4 years, identifying 1,702 breast cancer cases.
• Women with over 30% adult weight gain and first childbirth after 30—or no children—faced a 2.73 times higher breast cancer risk.
• The study is the first to quantify the interaction between weight gain and delayed or absent childbirth in elevating breast cancer risk.
• Lead researcher Lee Malcomson emphasized the need for GPs to recognize this high-risk profile and provide targeted lifestyle advice.
• The findings, though not yet peer-reviewed, align with rising trends in obesity and later motherhood, prompting calls for updated clinical guidelines.