title: The safety of transplanting cryopreserved ovarian tissue in cancer patients: a review of the literature.
abstract: BACKGROUND
  Transplantation of frozen/thawed ovarian tissue from patients with a malignant condition is associated with a risk of re-introduction of the disease as the tissue usually is removed before anti-cancer therapy and may thus contain malignant cells. We review studies investigating the presence of malignant cells in cryopreserved ovarian tissue from patients with malignant disease and based on the strength of the evidence, recommendations for transplantations are proposed.
  
  
  METHODS
  A systematic review of the literature. All peer reviewed studies evaluating the presence of malignant cells in cryopreserved human ovarian tissue were included. Data were searched in Pubmed and Embase with no language restrictions.
  
  
  RESULTS
  The majority of the reviewed papers were casuistic reports and few of the included papers were specifically designed to search for malignant cells. Ovarian tissue from 422 patients has been subject to testing for malignant cells by imaging, histology, immunohistochemistry, molecular biology, animal- or clinical transplantation. In 31 (7 %) of the cases the applied test raised suspicion of malignant cell infiltration. No transplantation-related relapse of cancer has been reported after 33 transplantations of frozen/thawed ovarian cortex.
  
  
  CONCLUSIONS
  The quality and strength of the evidence is generally low and prospective studies are needed. The risk of re-introducing a malignant condition when transplanting ovarian tissue depends on the particular disease. Based on the available data, the risk was estimated: Leukaemia: HIGH. Gastrointestinal cancers: MODERATE. Breast cancer, sarcomas of the bone and connective tissue, gynaecological cancers, Hodgkin's and Non-Hodgkin's Lymphoma: LOW.
authors.affiliation: Laboratory of Reproductive Biology, Copenhagen University Hospital-Rigshospitalet, Blegdamsvej 9., 2100, Copenhagen Ø, Denmark. mikro@dadlnet.dk
authors.forename: Mikkel
authors.initials: M
authors.lastname: Rosendahl
authors.forename: Tine
authors.initials: T
authors.lastname: Greve
authors.forename: Claus Yding
authors.initials: CY
authors.lastname: Andersen
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology / Q000517:prevention & control; D015925:Cryopreservation / Q000379:methods*; D016208:Databases, Factual; D005260:Female; D059247:Fertility Preservation / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D007247:Infertility, Female / Q000517:prevention & control; D007938:Leukemia / Q000473:pathology / Q000517:prevention & control; D008223:Lymphoma / Q000473:pathology / Q000517:prevention & control; D018365:Neoplasm, Residual / Q000517:prevention & control; D010053:Ovary / Q000473:pathology / Q000637:transplantation*; D012307:Risk Factors