6517 Background: Obesity (measured using body mass index [BMI]) is regarded as a prognostic factor for worse breast cancer survival. We hypothesized that obesity may influence adherence to NCCN guidelines recommending chemotherapy for patients with operable breast cancer at NCCN centers. Methods: We identified women < 70 years diagnosed with stage I, II, or III breast cancer from 1997 to 2006 at 8 NCCN centers for whom guidelines recommended chemotherapy. Body mass index was assessed in categories (<25 kg/m2 [normal], 25 to <30 kg/m2 [overweight], 30 to 39kg/m2 [obese], ≥40 kg/m2 [morbidly obese]) and in 5 kg/m2 increments. Multivariable logistic regression analysis adjusting for center, age at diagnosis, ethnicity, comorbidity score, and guideline was used to examine the association between BMI at diagnosis and non-receipt of chemotherapy. Results: 9,389 women were eligible for the study: 38% normal weight; 30% overweight; 23% obese; 5% morbidly obese; and 4% unknown. In multivariable analysis with BMI as a categorical variable, there was no association between weight status and non-receipt of chemotherapy (p = 0.35). When BMI was assessed in 5kg/m2 increments, weight status was a statistically significant predictor of non-receipt of chemotherapy (p = 0.02), but the odd ratios exceeded 1.0 only for BMIs ≥42.6kg/m2. Other patient-related factors associated with non-receipt of chemotherapy included older age at diagnosis (p < 0.01), presence of comorbidities (p < 0.01) and center (p < 0.01). Conclusions: Overall, the quality of breast cancer care as measured by adherence to NCCN guidelines recommending chemotherapy was not affected by patient overweight or obese status. Chemotherapy use was lower among patients with extreme morbid obesity, which may represent appropriate clinical decision-making. Evaluating factors that may contribute to worse prognosis among obese patients is essential for individualizing care and improving breast cancer outcome. No significant financial relationships to disclose.
Physical Activity, Weight, and Outcomes in Patients Receiving Chemotherapy for Metastatic Breast Cancer (C40502/Alliance)
