title: Invasive cervical cancer following cryotherapy for cervical intraepithelial neoplasia or human papillomavirus infection.
abstract: OBJECTIVE
  To determine the following: 1) the causes for the failure of cervical cryotherapy to prevent cervical cancer, and 2) whether cervical cryotherapy is associated with the development of cervical adenocarcinoma rather than squamous carcinoma.
  
  
  METHODS
  We reviewed the medical charts of 327 women with cervical cancer. One hundred forty-seven for whom pertinent history was missing were contacted by telephone or at clinic visits. History obtained verbally was confirmed by outside medical records. Cervical biopsies (N = 16) and endocervical curettages (ECCs) (N = 15) performed before cryotherapy and biopsies at the diagnosis of cancer (N = 21) were reviewed.
  
  
  RESULTS
  Twenty-one women with cervical cancer had a history of cryotherapy for cervical intraepithelial neoplasia (CIN) or human papillomavirus infection (HPV). The interval between cryotherapy and cancer was more than 2 years in 19 and more than 5 years in ten. Several categories of pre-treatment errors were identified. Evaluation before cryotherapy was appropriate in only nine cases. Interpretive errors were noted in three of 16 cervical biopsies and ten of 15 ECCs. After cryotherapy, 12% of women had appropriate follow-up. Of the invasive cancers that developed, 24% in the cryotherapy group and 21% in the non-cryotherapy group were adenocarcinomas.
  
  
  CONCLUSIONS
  Careful evaluation before cryotherapy, accurate pathology reports, and consistent long-term follow-up are necessary if cryotherapy is to be used to treat CIN or HPV. We found no evidence that cryotherapy is associated with the development of cervical adenocarcinoma.
authors.affiliation: Department of Obstetrics and Gynecology, Southern California Permanente Medical Group, San Diego.
authors.forename: C
authors.initials: C
authors.lastname: Schmidt
authors.forename: R G
authors.initials: RG
authors.lastname: Pretorius
authors.forename: M
authors.initials: M
authors.lastname: Bonin
authors.forename: L
authors.initials: L
authors.lastname: Hanson
authors.forename: N
authors.initials: N
authors.lastname: Semrad
authors.forename: W
authors.initials: W
authors.lastname: Watring
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology* / Q000473:pathology; D002278:Carcinoma in Situ / Q000601:surgery*; D002294:Carcinoma, Squamous Cell / Q000209:etiology*; D003452:Cryosurgery / Q000009:adverse effects*; D003475:Curettage; D005260:Female; D006801:Humans; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D027383:Papillomaviridae; D014412:Tumor Virus Infections / Q000601:surgery*; D002583:Uterine Cervical Neoplasms / Q000209:etiology* / Q000473:pathology / Q000601:surgery*