Wednesday, August 26, 2026 Exploration of body mass index and circulating metabolic factors as predictors of metformin benefit in the Canadian Cancer Trials Group MA.32Goodwin PJ, Ennis M, Chen BE, Gelmon KA, Whelan TJ, Ligibel JA, Thompson AM, Shepherd LE, Parulekar WR, Dowling R, Stambolic V. Exploration of body mass index and circulating metabolic factors as predictors of metformin benefit in the Canadian Cancer Trials Group MA.32. JNCI Cancer Spectr 10: pkag045. 2026. https://doi.org/10.1093/jncics/pkag045 In the MA.32 randomized adjuvant breast cancer trial, metformin (vs placebo) did not impact invasive disease-free survival or overall survival in estrogen and/or progesterone receptor–positive or –negative breast cancer; exploratory analyses suggested a benefit in HER2-positive breast cancer. Researchers investigated whether body mass index (BMI) and obesity-associated blood variables predicted metformin benefit in immunohistochemically defined breast cancer subtypes (luminal [estrogen/progesterone receptor positive, HER2 negative], triple-negative breast cancer [estrogen receptor, progesterone receptor, HER2 negative], HER2 positive).
