Led by Professor Simon Lord, Department of Oncology, and funded by the World Cancer Research Fund, the study assessed real-world obesity rates in more than 79,000 patients across 13 cancer types. The findings demonstrate that relying on a single body mass index (BMI) measurement at treatment initiation substantially underestimates lifetime obesity exposure, with important implications for prognostication and personalised care.
Obesity is a well-recognised risk factor for numerous cancers, including breast, colorectal, and liver cancers, and has been linked to higher rates of surgical complications, untoward drug effects, and disease recurrence. With the rapid rise in obesity prevalence over the last three decades, clinicians are increasingly treating patients with obesity-related cancers, as well as patients with other cancers co-presenting with insulin resistance and metabolic dysfunction.
While the link between obesity and cancer development is well established, how obesity relates to cancer outcomes remains uncertain, with studies to date reporting mixed findings.
To address this, the research team analysed electronic health record data containing longitudinal BMI measurements for patients receiving first-line systemic therapy – treatments delivered via the bloodstream, such as chemotherapy – in England between 2013-2023. The calculated both obesity prevalence at treatment initiation and lifetime obesity prevalence, defined as any recorded BMI ≥30 kg/m².