Comparison of ovarian stimulation response in patients with breast cancer undergoing ovarian stimulation with letrozole and gonadotropins to patients undergoing ovarian stimulation with gonadotropins alone for elective cryopreservation of oocytes†

Abstract

The primary objective of this study is to compare the oocyte yield in breast cancer patients undergoing controlled ovarian stimulation (COS) using letrozole and gonadotropins with patients undergoing COS with standard gonadotropins for elective cryopreservation of oocytes. Odds ratios (OR) for the number of mature oocytes were estimated. Pregnancy outcomes for breast cancer patients undergoing frozen-thawed 2-PN embryo transfers (FETs) after oncologic treatment were also noted. 220 and 451 cycles were identified in the breast cancer and the elective cryopreservation groups, respectively. Patients in the former group had lower peak estradiol levels [464.5 (315.5–673.8) pg/mL] compared to the latter [1696 (1058–2393) pg/mL; p < 0.01]. More oocytes were retrieved in the breast cancer group (12.3 ± 3.99) compared to the elective cryopreservation group (10.9 ± 3.86; p < 0.01). The odds for mature oocytes with letrozole and gonadotropins was 2.71 (95% CI 1.29–5.72; p = 0.01). Fifty-six FETs occurred in the breast cancer group. The clinical pregnancy and live birth rates per FET cycle were 39.7%, and 32.3%, respectively. Our findings suggest that COS with letrozole and gonadotropins yield more mature oocytes at lower estradiol levels compared to COS with gonadotropins alone. Breast cancer patients undergoing FET after oncologic treatment have live birth rates comparable to age-matched counterparts.

Chinese abstract

这项研究的主要目的是比较使用来曲唑和促性腺激素进行控制性卵巢刺激的乳腺癌患者和使用标准的促性腺激素进行控制性卵巢刺激 (COS) 来择期冷冻保存卵母细胞的患者的卵母细胞的产量。我们会计算成熟的卵母细胞的比值比 (OR) 。接受肿瘤治疗后的乳腺癌患者进行的冻融胚胎移植 (2PN) 后的妊娠结局也被记录在内。乳腺癌组和冷冻保存组分别确定有220和451个周期。与后一组[1696 (1058至2393) pg/ml;p < 0.01]相比, 前一组患者有较低的雌二醇峰值[464.5 (315.5-673.8) pg/ml]。乳腺癌组 (12.3 ± 3.99) 比择期冷冻组 (10.9 ± 3.86; p < 0.01) 保留了更多的卵母细胞。来曲唑和促性腺激素的成熟的卵母细胞的可能是2.71 (95%CI 1.29-5.72; P = 0.01) 。乳腺癌组出现56例冻融胚胎移植。两组每个周期FET临床妊娠率和活产率分别为39.75%,32.3%。我们的研究结果表明使用来曲唑和促性腺激素进行COS比单独使用促性腺激素进行COS能在较低的雌激素水平产生更多的成熟卵母细胞。乳腺癌患者接受肿瘤治疗后进行FET的活产率与和年龄匹配的配对者没有明显差别。

Keywords:

• Breast cancer
• cryopreservation
• fertility preservation
• letrozole
• ovarian stimulation

Declaration of interest

The authors report no conflicts of interest.