(P091) Sarcopenia/Cachexia Is Associated With Reduced Survival and Locoregional Control in Head and Neck Cancer Patients Receiving Radiotherapy: Results From Quantitative Imaging Analysis of Lean Body Mass

Sasikarn Chamchod, MD, Clifton D. Fuller, MD, PhD, Aaron J. Grossberg, MD, PhD, Abdallah S. Mohamed, MD, MSc, Jolien Heukelom, MD, Hillary Eichelberger, BA, BS, Michael E. Kantor, BS, Gary B. Gunn, MD, Adam S. Garden, MD, Steven J. Frank, MD, Jack Phan, MD, PhD, Beth M. Beadle, MD, PhD, Heath D. Skinner, MD, PhD, William H. Morrison, MD, Debra A. Ruzensky, RD, David I. Rosenthal, MD; Radiation Oncology Unit, Chulabhorn Hospital; Department of Radiation Oncology, UT MD Anderson Cancer Center; Department of Radiation Oncology, Netherlands Cancer Institute; UT Medical School, Houston

BACKGROUND: Major weight loss before or during head and neck squamous cell cancer (HNSCC) treatment is common. We investigated the impact of weight loss, cachexia, and sarcopenia-the isolated loss of lean body mass-as determined by a novel method using routine staging positron emission tomography-computed tomography (PET-CT) scans on cancer treatment outcomes.

METHODS: Biometric data were collected on consecutive patients with American Joint Committee on Cancer (AJCC) stage IVA–IVB HNSCC treated with radiation therapy (RT) with or without concurrent chemotherapy between 2003 and 2013 and who had paired pre- and posttreatment PET-CTs. Cachexia was defined as > 5% weight loss for < 6 months or body mass index (BMI) < 20 kg/m² with 2% weight loss. Sarcopenia was defined by CT-measured L3 skeletal muscle index of < 52.4 cm²/m² for men and < 38.5 cm²/m² for women, as described by Prado et al (2013). We evaluated the effect of pre- and post-RT sarcopenia on outcomes. Survival curves were constructed using the Kaplan-Meier technique. Log-rank test was used to compare outcomes. Univariate and multivariate overall survival (OS) modeling was performed using parametric survival fitting to allow intramodel comparison using corrected Bayesian information criteria (BIC).

RESULTS: A total of 175 patients were identified, and the median follow-up was 67.9 months. We detected sarcopenia in 65 patients (37.1%) prior to RT. Sarcopenia was identified in an additional 47 of 110 patients (42.7%) on the post-RT scan. All patients who developed sarcopenia on the post-RT study had decreased locoregional control (LRC), OS, and disease-specific survival (DSS) (P < .05 for all). Sarcopenia that was identified on the pre-RT PET-CT showed the same patterns but only for nonoperated patients, where the 5-year OS was decreased from 66.7 ± 1.0% to 17.8 ± 10.2% (P < .001). Posttreatment sarcopenia was more substantive in competing multivariate models of mortality risk than simple weight and BMI-based cachexia metrics (ΔBIC ≥ 12.9).

DISCUSSION: We confirm that analysis of routine CT scans for sarcopenia can predict outcomes for HNSCC patients. Pre-RT sarcopenia is associated with more poor outcomes for nonoperated patients and post-RT sarcopenia for all HNSCC patients. Post-RT sarcopenia, as measured by routine CT, outperformed simple weight loss and BMI-derived cachexia metrics, because loss of lean muscle mass can occur independently of BMI status. These findings suggest the potential benefit for investigating intervention with aggressive nutritional and physiatric methods to prevent sarcopenia during RT and to study how these interventions might affect outcomes in nonoperated, pre-RT sarcopenia patients.

Proceedings of the 97th Annual Meeting of the American Radium Society- americanradiumsociety.org