104P Obesity and recurrence in postmenopausal, estrogen-receptor-positive breast cancer patients treated with adjuvant aromatase inhibitors: A Danish population-based cohort study

Clinical studies confirm that obesity is a key risk factor for recurrence in postmenopausal women with estrogen receptor (ER)-positive breast cancer. Concerning evidence suggests do not obtain similar protection from aromatase inhibitors (AI) as healthy-weight women. We examined cohort of diagnosed stage I-III ER+ cancer 1998-2016, treated AIs the adjuvant setting. The study was conducted using data Danish Breast Cancer Group and information on height weight supplemented Anesthesiology database. Body mass index (BMI) classified I) (18.5-24.9 kg/m2), II) overweight (25-29.9 III) (30-34.9 IV) severe (≥ 35 kg/m2) World Health Organization guidelines. Follow-up began six months after surgery continued to first event recurrence, contralateral cancer, another malignancy, death, emigration, end clinical follow-up, or 25th September 2018. used Cox regression estimate crude adjusted hazard ratios (HRs) 95% confidence intervals (95% CI). model patient, tumor treatment characteristics. From original 44,449 eligible patients, we enrolled patients who were postmenopausal, had ER-positive AIs, BMI (N=13,261). There 442 recurrences over 37,668 person-years follow-up among healthy-weight, 339 27,061 overweight, 165 11,843 82 5,234 obesity. Multivariable analyses revealed increased hazards associated (HR: 1.09 [95% CI: 0.95-1.26]), 1.22 1.02-1.46]) 1.42 1.12-1.80]), compared healthy-weight. Obesity an early-stage AIs.