Abstract P5-15-02: Safety of letrozole-gonadotropin controlled ovarian stimulation protocol in women with breast cancer undergoing fertility preservation before or after tumor resection via embryo or oocyte cryopreservation: A prospective cohort study
Authors: Oktay Kutluk , Kim Jayeon , Bedoschi Giuliano , Turan Volkan 
Published: May 2015

Purpose: We have previously described the concurrent use of aromatase inhibitors to reduce estrogen exposure in women with breast cancer undergoing controlled ovarian stimulation (COS) with gonadotropins for fertility preservation (FP) via oocyte or embryo cryopreservation. To purpose of this study was to investigate the impact of this letrozole-gonadotropin COS protocol on survival in women who underwent fertility preservation before or after breast surgery.

Patients and Methods: A total of 364 women with stage ≤3 breast cancer, who pursued FP consultation or FP treatments at our institution were prospectively evaluated. Of those, 146 elected to undergo COS with letrozole and gonadotropins for FP (120 prior to chemotherapy and 26 after chemotherapy). The remaining 218 patients elected to not to undergo a fertility-preserving procedure and served as controls.

Result(s): Demographic information and tumor characteristics at enrollment were similar between patients who pursued COS with letrozole and gonadotropins (COS group) and control groups.

Table 1. Demographics and tumor characteristics of patients who pursued fertility preservation vs. controls Treatment Group (n=120)Control Group (n=218)P-valueAge at FP consultation (years)35.2±4.537.0±5.10.03Age at cancer diagnosis (years)34.8±4.534.9±4.70.88BMI (kg/m2)22.8±3.723.1±3.90.56Node involvement (%)34480.02Tumor size (cm)   Mean±SD1.8 ±1.21.9±1.90.62&lt;267660.592-53130 &gt;523 Lymphovascular space invasion (%)31370.44Histologic grade   1-240391.0035759 Estrogen receptor positive (%)82770.27HER-2/neu positive (%)35330.78Adjuvant tamoxifen use (%)89871.00Length of follow-up (years, Mean±SD)5.0±2.16.9±3.6&lt;0.001

The median follow-up after diagnosis was 4.9 years in COS and 6.2 years in the control group. In the COS group, the hazard ratio (HR) for recurrence after IVF was 0.77 (95% CI: 0.28, 2.13) and the survival was not compromised compared with controls (P=0.61). In the COS group, survival was not different between patients with ER-positive and ER-negative breast cancer (P=0.75) and between patients who underwent COS before and after tumor resection (P=0.56). The survival was also not different between patients who pursued COS before and after chemotherapy (P=0.57).

Conclusion(s): Here we presented the largest prospective data with longest follow up on the safety of ovarian stimulation in women with breast cancer. COS with letrozole and gonadotropins for FP is unlikely to cause substantially increased recurrence risk in breast cancer, even in patients who have not yet undergone breast surgery. Larger studies are needed to confirm the findings from the subgroup analysis.

Support: Supported by NIH RO1 HD053112.

Citation Format: Kutluk Oktay, Jayeon Kim, Giuliano Bedoschi, Volkan Turan. Safety of letrozole-gonadotropin controlled ovarian stimulation protocol in women with breast cancer undergoing fertility preservation before or after tumor resection via embryo or oocyte cryopreservation: A prospective cohort study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-15-02.