Abstract P1-09-01: Beyond fatigue – The impact of breast cancer treatment on body composition and energy expenditure
Authors: Miller Kathy D , Sollars Jessica L , Althouse Sandra K , Han Linda K , Ventura Stephen J , Sledge Jeffrey S 
Published: May 2015

Background: Patients (pts) frequently report ‘fatigue’ as a consequence of breast cancer therapy but the true impact of cancer treatments on body composition and energy expenditure has not been measured.

Patients and Methods: Pts with stage 0-III were evaluated prior to any therapeutic intervention to assess baseline health status, at 6 months to assess acute impact of therapy, and at 12 months to assess chronic effects and ‘spontaneous’ recovery. Measurements included body composition, maximum watts produced and power envelope (watts/kg) based on laboratory testing, energy expenditure over 7 days in real world conditions, insulin resistance (HOMA), fatigue (BFI), quality of life scales (FACT-B), and serum for insulin-like growth factor-1 (IGF-1), adiponectin, leptin, markers of bone formation (P1NP, BSAP, osteocalcin), bone resorption (sCTX), and bone mineral metabolism (PTH, 25-OH Vit D).

Results: 45 patients have been enrolled; 25 have completed the 6 month assessment to date. Median age was 52 (30-68). Patients were analyzed separately based on therapies received.

 Chemotherapy +/- HRTHormone TherapyLocal Therapy Only Baseline (n=23)6 months (n=12)Baseline (n=14)6 months (n=11)Baseline (n=8)6 months (n=2)BMI (kg/m2)27.826.328.729.332.028.2Lean mass (kg)39.536.342.041.143.036.1Body fat (%)43.947.346.550.649.445.6HOMA-IR*1.751.771.211.812.101.18Peak power (Watts)68.244.170539788.5Watts/kg lean muscle1.71,21.71.32.32.4Time to zero power (min.sec)^12.36.399.56.911.210.6*HOMA-IR was not assessed in patients known to have diabetes. ^Time to zero power quantifies the time over which patients can sustain generating motive power as a measure of endurance.

Week long bi-axial pedometry studies at baseline and six months revealed a decrease in pt activity between 17 and 23 percent, confirming the decrease in motive power seen in the power envelope and body composition tests. Enrollment continues to a planned total of 75 pts. Additional follow-up with 12 month assessment, as well as QOL and serum data will be presented.

Conclusions: Pts in this study were more deconditioned than expected based on population normative data. Systemic therapy had a profound impact on body composition with a substantial decrease in lean muscle mass with a corresponding increase in % body fat and decrease in the ability to generate and sustain motive power. Our data suggest that most patients would not be able to participate in or comply with commonly proposed exercise interventions and physical activity recommendations. Future interventions need to be restructured, following the model of individualized rehabilitation with careful assessment of the pts baseline status to improve the health of breast cancer survivors.

Citation Format: Kathy D Miller, Jessica L Sollars, Sandra K Althouse, Linda K Han, Stephen J Ventura, Jeffrey S Sledge. Beyond fatigue – The impact of breast cancer treatment on body composition and energy expenditure [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-01.