Sarcopenia to predict tolerance of adjuvant breast cancer chemotherapy

138 Background: Despite improved survival with adjuvant chemotherapy among older women, it is less often recommended for fear they cannot complete therapy or will have excessive toxicity. Analytic morphometrics uses objective imaging measurements such as muscle size, bone mineral density (BMD) and body composition to improve risk stratification. We examined whether morphometrics might help predict toxicity of chemotherapy in breast cancer patients. Methods: Our prospective IRB-approved breast cancer database was queried for all patients who underwent adjuvant or neoadjuvant chemotherapy and had CT scans of the chest, abdomen and pelvis prior to chemo. Complications of chemotherapy were graded according to the NCI-CTC. CT scans were processed using semi-automated algorithms (MATLAB v13.0) to measure psoas area (PA) and density (PD), BMD and subcutaneous fat (SF), visceral fat (VF), and total body area (TBA. Outcome (DFS and OS) was assessed by K-M, and logistic regression models and ANOVA were used for toxicity events. Results: We identified 129 patients, ranging in age from 24 to 83 (median 52). 105 (81%) received AC/T while 19% received alternate regimens, all full weight based. T-stage, nodal status and HER2 expression were significantly associated with measures of obesity, except BMI, but not sarcopenia. After adjusting for stage and Her-2, BMI remained a significant predictor of DFS (OR 1.07 (95%CI 1.01, 1.13)) and OS (OR 1.06 (95% CI 1.00, 1.12)).After controlling for age, PD and VF were predictors of chemotherapy completion. The OR for completing chemotherapy decreased 0.95 (95% CI: 0.90, 1.01, p=0.08) for every increase of 1000 in VF and increased 1.08 (95% CI: 1.01, 1.15, p=0.03) for every unit increase in PD. Sarcopenia was associated with an increased risk of pulmonary complications (p=0.01) and anemia (p=0.06). Conclusions: Although age is a significant predictor of increased toxicity and inability to complete chemotherapy, sarcopenia is an objective, independent predictor of chemotherapy completion. Psoas density, easily obtainable from a pre-treatment CT scan, can help the clinician older breast cancer patients for adjuvant chemotherapy.