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Poster Display session 1

3821 - Efficacy and safety of controlled ovarian stimulation with or without letrozole co-administration for fertility preservation: A systematic review and meta-analysis.


28 Sep 2019


Poster Display session 1


Supportive Care and Symptom Management

Tumour Site


Benedetta Bonardi


Annals of Oncology (2019) 30 (suppl_5): v718-v746. 10.1093/annonc/mdz265


B. Bonardi1, M. Bruzzone2, O. Goldrat3, L. Del Mastro4, P. Anserini5, C. Massarotti5, G. Mangili6, M. Ceppi2, I. Demeestere1, M. Lambertini7

Author affiliations

  • 1 Research Laboratory On Human Reproduction, Université Libre de Bruxelles-Erasme, 1070 - Bruxelles/BE
  • 2 Clinical Epidemiology, Policlinico San Martino, 16132 - Genova/IT
  • 3 Fertility Clinic, Clinique Universitaire de Bruxelles-Hôpital Erasme, 1070 - Bruxelles/BE
  • 4 Internal Medicine Dept., IRCCS AOU San Martino - IST-Istituto Nazionale per la Ricerca sul Cancro, 16132 - Genova/IT
  • 5 Obstetrics And Gynecology Clinic, Policlinico San Martino, 16132 - Genova/IT
  • 6 Obstetrics And Gynecology, IRCCS Ospedale San Raffaele, 20132 - Milan/IT
  • 7 Medical Oncology Departmentinternal Medicine Dept., IRCCS AOU San Martino - IST-Istituto Nazionale per la Ricerca sul Cancro, 16132 - Genova/IT


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Abstract 3821


Mature oocyte vitrification and storage is currently used to help patients preserving their ability to have offspring either for fertility preservation (FP) before gonadotoxic treatment such as chemotherapy or for elective purposes. Our meta-analysis investigated whether letrozole co-administration during controlled ovarian stimulation (COS) for FP is effective and safe.


A literature search using PubMed was conducted up to March 8th, 2019 to retrieve information from studies that compared the performance of COS with or without letrozole co-administration for FP. Mean or median values and 95% confidence intervals (CIs) or standard deviations (SDs) were collected for efficacy (number of collected oocytes, number of mature oocytes, maturation rate) and safety (peak estradiol levels [E2], total gonadotropin dose, number of stimulation days) endpoints. Statistical analysis was conducted with random-effects model.


A total of 10 articles were eligible including 1930 patients undergoing COS with or without letrozole. Studies compared COS with and without letrozole in cancer or infertile cohorts (N = 9) and infertile cohort only (N = 1). The total number of oocytes and mature oocytes collected were similar between letrozole and no letrozole groups while the peak estradiol was significantly higher in the standard COS without letrozole (Table).Table:


MR (letrozole vs no letrozole)95% CIP-value
Collected oocytes1.020.90-1.160.748
Mature oocytes0.980.83-1.160.830
Maturation rate0.940.86-1.030.181
Peak E20.270.22-0.32<0.001
Total gonadotropin0.970.86-1.100.676
Length of stimulation1.000.95-1.040.849


Letrozole co-administration during COS resulted to be as effective as standard COS but with significantly decreased peak estradiol levels, suggesting its increased safety especially for hormone-sensitive cancer patients.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.


Has not received any funding.


All authors have declared no conflicts of interest.

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