Effect of Previous Chemotherapy on the Quality of Cryopreserved Human Ovarian Tissue In Vitro

PLoS One. 2015 Jul 30;10(7):e0133985. doi: 10.1371/journal.pone.0133985. eCollection 2015.

Abstract

Background: Cryopreservation of ovarian tissue has been widely accepted as an option for fertility preservation among cancer patients. Some patients are exposed to chemotherapy prior to ovarian tissue cryopreservation. Consequently, assessment of the developmental capacity of human ovarian tissue after chemotherapy is of primary importance.

Materials: In order to study the impact of previous chemotherapy on in vitro development and viability of ovarian follicles, quality control samples from 34 female cancer patients at median age of 15 years (range 1‒35), cryopreserved for fertility preservation before (n = 14) or after (n = 20) initiation of chemotherapy, were thawed and cultured for 7 days. The morphology and developmental stages of ovarian follicles were studied by light microscopy before and after culture. Possible associations between follicular densities, age and exposure to alkylating agents, expressed as cyclophosphamide equivalent dose (CED) were tested.

Results: Exposure to chemotherapy significantly impaired the survival and development of ovarian follicles in culture. After seven days, significantly higher densities of intermediary, primary and secondary follicles and lower densities of atretic follicles was detected in the samples collected before chemotherapy. Increasing dose of alkylating agents was identified by multivariate linear regression analysis as an independent predictor of a higher density of atretic follicles, whereas increasing age of the patient predicted a better outcome with less follicle atresia and a higher density of maturing follicles.

Conclusion: This study provides quantitative in vitro evidence of the impact of chemotherapy on developmental capacity of cryopreserved human ovarian tissue. The results indicate that fertility preservation should be carried out, if possible, before initiation of alkylating agents in order to guarantee better in vitro survival of ovarian follicles. In addition, ovarian samples from younger girls show lower viability and fewer developing follicles in culture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antineoplastic Agents / adverse effects*
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Cryopreservation / methods
  • Female
  • Humans
  • Infant
  • Ovarian Follicle / drug effects*
  • Tissue Culture Techniques / methods
  • Young Adult

Substances

  • Antineoplastic Agents

Grant support

This research was supported by grants from the Norwegian National Advisory Unit on Women’s Health, Oslo University Hospital, Norway; the Swedish Childhood Cancer Foundation; the Finnish Cancer Society; the Finnish Pediatric Research Foundation; the Paulo Foundation; the Väre Foundation for Pediatric Cancer Research; the Academy of Finland; The Swedish Research Council; ALF Stockholm County and the Karolinska Institute. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.