title: Skeletal Muscle Measures as Predictors of Toxicity, Hospitalization, and Survival in Patients with Metastatic Breast Cancer Receiving Taxane-Based Chemotherapy.
abstract: OBJECTIVE
  Severe skeletal muscle (SM) loss (sarcopenia) is associated with poor cancer outcomes, including reduced survival and increased toxicity. This study investigates SM measures in metastatic breast cancer (MBC) patients receiving first-line taxane-based chemotherapy and evaluates associations with treatment toxicity and other outcomes.
  
  
  METHODS
  Using computerized tomography (CT) images taken for the evaluation of disease burden, skeletal muscle area (SMA), and density (SMD) were measured at the third lumbar vertebrae. Sarcopenia was defined as skeletal muscle index (SMI = SMA/height2) ≤ 41. Skeletal muscle gauge (SMG) was created by multiplying SMI × SMD. Fisher exact tests, t tests, the Kaplan-Meier method, and Cox regression modeling were used.
  
  
  RESULTS
  MBC patients (N = 40), median age 55 (range, 34-80), 58% sarcopenic, median SMG 1296 AU (SD, 522). Grade 3-4 toxicity was found in 57% of sarcopenic versus 18% of non-sarcopenic patients (P = 0.02). Toxicity-related hospitalizations were also higher in sarcopenic patients (39% vs. 0%, P = 0.005) as were any adverse events-defined as any grade 3-4 toxicities, hospitalizations, dose reductions, or dose delay-(74% vs. 35%, P = 0.02). Low SMG was associated with grade 3-4 toxicity (P = 0.04), hospitalization (P = 0.01), and time to treatment failure (for progression or toxicity; P = 0.03). Low SMG had a borderline significant association with any adverse event (P = 0.06) and overall survival (P = 0.07).
  
  
  CONCLUSIONS
  SM measures are associated with toxicity outcomes and survival in MBC patients receiving first-line taxane-based chemotherapy. Further studies are needed to explore how routinely obtained CT scans can be used to individualize dosing and improve treatment planning. Clin Cancer Res; 23(3); 658-65. ©2016 AACR.
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina. s_shachar@rambam.health.gov.il.|Division of Oncology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Shlomit Strulov
authors.initials: SS
authors.lastname: Shachar
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Deal
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
authors.forename: Marc
authors.initials: M
authors.lastname: Weinberg
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
authors.forename: Kirsten A
authors.initials: KA
authors.lastname: Nyrop
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
authors.forename: Grant R
authors.initials: GR
authors.lastname: Williams
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
authors.forename: Tomohiro F
authors.initials: TF
authors.lastname: Nishijima
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Benbow
authors.affiliation: UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina.
authors.forename: Hyman B
authors.initials: HB
authors.lastname: Muss
mesh_terms: D000230:Adenocarcinoma / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000556:secondary*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000009:adverse effects*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001823:Body Composition; D015992:Body Mass Index; D001830:Body Surface Area; D001943:Breast Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000473:pathology; D009929:Organ Size; D011379:Prognosis; D016016:Proportional Hazards Models; D055948:Sarcopenia / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000209:etiology; D013046:Specific Gravity; D043823:Taxoids / Q000008:administration & dosage / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D043823:Taxoids