title: Association of Body Composition With Survival and Locoregional Control of Radiotherapy-Treated Head and Neck Squamous Cell Carcinoma.
abstract: OBJECTIVE
  Major weight loss is common in patients with head and neck squamous cell carcinoma (HNSCC) who undergo radiotherapy (RT). How baseline and posttreatment body composition affects outcome is unknown.
  
  
  OBJECTIVE
  To determine whether lean body mass before and after RT for HNSCC predicts survival and locoregional control.
  
  
  METHODS
  Retrospective study of 2840 patients with pathologically proven HNSCC undergoing curative RT at a single academic cancer referral center from October 1, 2003, to August 31, 2013. One hundred ninety patients had computed tomographic (CT) scans available for analysis of skeletal muscle (SM). The effect of pre-RT and post-RT SM depletion (defined as a CT-measured L3 SM index of less than 52.4 cm2/m2 for men and less than 38.5 cm2/m2 for women) on survival and disease control was evaluated. Final follow-up was completed on September 27, 2014, and data were analyzed from October 1, 2014, to November 29, 2015.
  
  
  METHODS
  Primary outcomes were overall and disease-specific survival and locoregional control. Secondary analyses included the influence of pre-RT body mass index (BMI) and interscan weight loss on survival and recurrence.
  
  
  RESULTS
  Among the 2840 consecutive patients who underwent screening, 190 had whole-body positron emission tomography-CT or abdominal CT scans before and after RT and were included for analysis. Of these, 160 (84.2%) were men and 30 (15.8%) were women; their mean (SD) age was 57.7 (9.4) years. Median follow up was 68.6 months. Skeletal muscle depletion was detected in 67 patients (35.3%) before RT and an additional 58 patients (30.5%) after RT. Decreased overall survival was predicted by SM depletion before RT (hazard ratio [HR], 1.92; 95% CI, 1.19-3.11; P = .007) and after RT (HR, 2.03; 95% CI, 1.02-4.24; P = .04). Increased BMI was associated with significantly improved survival (HR per 1-U increase in BMI, 0.91; 95% CI, 0.87-0.96; P < .001). Weight loss without SM depletion did not affect outcomes. Post-RT SM depletion was more substantive in competing multivariate models of mortality risk than weight loss-based metrics (Bayesian information criteria difference, 7.9), but pre-RT BMI demonstrated the greatest prognostic value.
  
  
  CONCLUSIONS
  Diminished SM mass assessed by CT imaging or BMI can predict oncologic outcomes for patients with HNSCC, whereas weight loss after RT initiation does not predict SM loss or survival.
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Grossberg
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston3Radiation Oncology Unit, Chulabhorn Hospital, Bangkok, Thailand.
authors.forename: Sasikarn
authors.initials: S
authors.lastname: Chamchod
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Clifton D
authors.initials: CD
authors.lastname: Fuller
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston4Department of Clinical Oncology and Nuclear Medicine, Faculty of Medicine, University of Alexandria, Alexandria, Egypt.
authors.forename: Abdallah S R
authors.initials: AS
authors.lastname: Mohamed
authors.affiliation: Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
authors.forename: Jolien
authors.initials: J
authors.lastname: Heukelom
authors.affiliation: currently a medical student at University of Texas Medical School at Houston.
authors.forename: Hillary
authors.initials: H
authors.lastname: Eichelberger
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Kantor
authors.affiliation: Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Hutcheson
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: G Brandon
authors.initials: GB
authors.lastname: Gunn
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Garden
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Steven
authors.initials: S
authors.lastname: Frank
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Jack
authors.initials: J
authors.lastname: Phan
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Beth
authors.initials: B
authors.lastname: Beadle
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Heath D
authors.initials: HD
authors.lastname: Skinner
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: William H
authors.initials: WH
authors.lastname: Morrison
authors.affiliation: Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
authors.forename: David I
authors.initials: DI
authors.lastname: Rosenthal
mesh_terms: D000328:Adult; D000368:Aged; D001823:Body Composition; D015992:Body Mass Index; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000503:physiopathology* / Q000532:radiotherapy*; D023381:Endpoint Determination; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology / Q000503:physiopathology* / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D000077195:Squamous Cell Carcinoma of Head and Neck; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology