title: Occult Uterine Sarcoma and Leiomyosarcoma: Incidence of and Survival Associated With Morcellation.
abstract: OBJECTIVE
  To estimate the incidence of occult uterine sarcoma and leiomyosarcoma in hysterectomies for leiomyomas and the risk associated with their morcellation.
  
  
  METHODS
  We conducted a population-based cohort study. All uterine sarcomas from 2006-2013 in an integrated health care system were identified. Age- and race-specific incidences of occult uterine sarcoma were calculated. Kaplan-Meier survival analysis was performed. Crude and adjusted risk ratios of recurrence and death associated with morcellation at 1, 2, and 3 years were estimated using Poisson regression with inverse probability weighting.
  
  
  RESULTS
  There were 125 hysterectomies with occult uterine sarcomas identified among 34,728 hysterectomies performed for leiomyomas. The incidence of occult uterine sarcoma and leiomyosarcoma was 1 of 278 or 3.60 (95% confidence interval [CI] 2.97-4.23) and 1 of 429 or 2.33 (95% CI 1.83-2.84) per 1,000 hysterectomies. For stage I leiomyosarcoma (n=111), eight (7.2%) were power and 27 (24.3%) nonpower-morcellated. The unadjusted 3-year probability of disease-free survival for no morcellation, power and nonpower morcellation was 0.54, 0.19, and 0.51, respectively (P=.15); overall survival was 0.64, 0.75, and 0.68, respectively (P=.97). None of the adjusted risk ratios for recurrence or death were significant except for death at 1 year for power and nonpower morcellation groups combined (6/33) compared with no morcellation (4/76) (5.12, 95% CI 1.33-19.76, P=.02). We had inadequate power to infer differences for all other comparisons including 3-year survival and power morcellation.
  
  
  CONCLUSIONS
  Morcellation is associated with decreased early survival of women with occult leiomyosarcomas. We could not accurately assess associations between power morcellation and 3-year survival as a result of small numbers.
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, California; the Institute for Health Research, Kaiser Permanente Colorado, Denver, Colorado; the Permanente Federation, LLC, Kaiser Permanente, Oakland, the Departments of Obstetrics and Gynecology and Gynecology Oncology, The Permanente Medical Group, Oakland and San Francisco, California; Colorado Permanente Medical Group, Denver and Aurora, Colorado; and Southern California Permanente Medical Group, Los Angeles, California.
authors.forename: Tina
authors.initials: T
authors.lastname: Raine-Bennett
authors.forename: Lue-Yen
authors.initials: LY
authors.lastname: Tucker
authors.forename: Eve
authors.initials: E
authors.lastname: Zaritsky
authors.forename: Ramey D
authors.initials: RD
authors.lastname: Littell
authors.forename: Ted
authors.initials: T
authors.lastname: Palen
authors.forename: Romain
authors.initials: R
authors.lastname: Neugebauer
authors.forename: Allison
authors.initials: A
authors.lastname: Axtell
authors.forename: Peter M
authors.initials: PM
authors.lastname: Schultze
authors.forename: David W
authors.initials: DW
authors.lastname: Kronbach
authors.forename: Julia
authors.initials: J
authors.lastname: Embry-Schubert
authors.forename: Alvina
authors.initials: A
authors.lastname: Sundang
authors.forename: Kimberly
authors.initials: K
authors.lastname: Bischoff
authors.forename: Amy L
authors.initials: AL
authors.lastname: Compton-Phillips
authors.forename: Scott E
authors.initials: SE
authors.lastname: Lentz
mesh_terms: D002140:California / Q000453:epidemiology; D003120:Colorado / Q000453:epidemiology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007044:Hysterectomy / Q000379:methods; D015994:Incidence; D033162:Incidental Findings; D053208:Kaplan-Meier Estimate; D007889:Leiomyoma / Q000601:surgery*; D007890:Leiomyosarcoma / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D008875:Middle Aged; D000069577:Morcellation / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009382:Neoplasms, Unknown Primary / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D015996:Survival Rate; D063186:Uterine Myomectomy; D014594:Uterine Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology / Q000601:surgery*