Body Mass Index and patient-reported function, quality of life and treatment toxicity in women receiving adjuvant chemotherapy for breast cancer

Background: This study investigates whether high body mass index (BMI) in women diagnosed with early breast cancer (BC) is associated with patient-reported symptom severity during chemotherapy. Methods: Women with Stage I-III BC completed toxicity reports for 17 side effects during regularly scheduled chemotherapy infusions. Toxicity reports were compared in women with obesity (BMI >=30) versus no obesity (BMI <30). Fisher’s exact tests and 2-sample t-tests compared baseline patient characteristics. Risk ratios (RR) for women with obesity as compared to no obesity were estimated for individual symptoms that were patient-rated as moderate, severe or very severe (MSVS) severity, adjusting for marital status and race. Results: In a sample of 286 patients, Black women comprised 23% of the sample. The obesity rate was 76% among Black patients and 31% among White patients (p<.0001). Women with obesity rated an average of 6.9 side effects (standard deviation, SD 4.2) as MSVS vs 5.5 side effects (SD 3.7) among women with no obesity (p=.003). In adjusted analysis, women with obesity had significantly greater risk for MSVS fatigue (RR 1.18, 95% CI 1.01-1.36), dyspnea (RR 1.71, 95% CI 1.09-2.69), arthralgia (RR 1.47, 95% CI 1.10-1.97), peripheral neuropathy (RR 1.45, 95% CI 1.01-2.08), edema of limbs (RR 1.84, 95% CI 1.18-2.88), and abdominal pain (RR 1.75, 95% CI 1.07-2.87). There were no inter-group differences in BC stage or phenotype, chemotherapy treatment modifications, or hospitalizations. Conclusions: Among women with early BC, patients with obesity reported higher chemotherapy toxicity as compared to patients without obesity; however, this did not result in differences in treatment completion.