title: Morphomics predicts response to ipilimumab in patients with stage IV melanoma.
abstract: BACKGROUND
  Factors predictive of response to immunotherapy are needed to select appropriate patients. As morphometric analysis can be an objective surrogate for underlying physiology, we explored the possibility that morphomics may predict response among stage IV melanoma patients treated with ipilimumab.
  
  
  METHODS
  We identified stage IV melanoma patients treated with ipilimumab who had an appropriate CT scan within a 6 month window. Using semi-automated algorithms, we acquired several morphomic measurements. Toxicity and response rate compared by quartile using Fisher's exact test or chi-square, while survival after initiation of ipilimumab was compared by quartile using the log-rank test.
  
  
  RESULTS
  While there was a significant correlation between toxicity and response (P < .003), morphomics failed to predict either severity of toxicity or specific side effects. Psoas density was significantly associated with response rate, both excluding stable disease (36.4% vs 9.1%, P = .054), and including stable disease (54.5% versus 18.2%, P = 0.045). Survival after initiation of ipilimumab was significantly associated with psoas density (P = 0.04) and visceral fat distance (P = 0.022).
  
  
  CONCLUSIONS
  In an exploratory study of patients with metastatic melanoma being treated with ipilimumab, psoas density and spine-fascia distance correlated with response and survival. Pre-treatment morphomic analysis, as a correlate of underlying physiology, may help predict response to immunotherapy.
authors.affiliation: Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Sabel
authors.affiliation: Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Jay
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Anran
authors.initials: A
authors.lastname: Wang
authors.affiliation: Department of Medicine, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Christopher
authors.initials: C
authors.lastname: Lao
authors.affiliation: Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Sven
authors.initials: S
authors.lastname: Holcombe
authors.affiliation: Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Stewart
authors.initials: S
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000074324:Ipilimumab; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality / Q000556:secondary*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D000074324:Ipilimumab
keywords: immunotherapy; ipilimumab; melanoma; morphomics