Letrozole for ovulation induction and fertility preservation by embryo cryopreservation in young women with endometrial carcinoma

Fertil Steril. 2007 Sep;88(3):657-64. doi: 10.1016/j.fertnstert.2006.12.068. Epub 2007 Apr 10.


Objective: To reduce estrogen exposure in women with endometrial cancer undergoing in vitro fertilization using an aromatase inhibitor.

Design: Prospective case series.

Setting: Academic center for reproductive medicine.

Patient(s): Endometrial carcinoma patients presenting for fertility preservation or fresh embryo transfer to gestational carrier.

Intervention(s): Four patients with endometroid carcinoma underwent five IVF cycles for immediate or delayed embryo transfer to gestational carriers before or after staging and definitive surgery. To prevent surge in E(2) levels, letrozole was started 2 days before gonadotropin administration and then given concomitantly. Embryos were either cryopreserved for fertility preservation or transferred freshly to a surrogate.

Main outcome measure(s): Peak E(2) level during stimulation, pregnancy in a gestational carrier.

Result(s): Peak E(2) level during stimulation was 386.67 +/- 102.93 pg/mL. A mean of 7 +/- 2.85 oocytes were retrieved, resulting in 4.8 +/- 1.76 embryos per cycle. In one patient, two embryos were transferred to a surrogate, resulting in a triplet pregnancy. The delivery occurred at 31 weeks and the infants did not show any congenital or developmental abnormalities. Three patients had their embryos cryopreserved for future use.

Conclusion(s): The use of letrozole and gonadotropins is associated with lower E(2) levels compared with standard stimulation cycles in endometrial carcinoma patients. Combination of this approach with surrogacy may enable these young women to preserve their fertility.

MeSH terms

  • Antineoplastic Agents / therapeutic use*
  • Cryopreservation
  • Endometrial Neoplasms / drug therapy*
  • Female
  • Fertility / drug effects*
  • Fertilization in Vitro*
  • Humans
  • Letrozole
  • Nitriles / therapeutic use*
  • Organ Preservation / methods*
  • Ovulation Induction / methods*
  • Pregnancy
  • Pregnancy Outcome
  • Prospective Studies
  • Triazoles / therapeutic use*


  • Antineoplastic Agents
  • Nitriles
  • Triazoles
  • Letrozole