麻豆传媒

SAN ANTONIO -- Using fertility preservation and/or assisted reproductive technologies (ART) did not adversely impact 3-year cancer recurrence rates among patients with hormone receptor (HR)-positive breast cancer who paused endocrine therapy to become pregnant, according to research presented here.

An analysis from the prospective POSITIVE study showed that younger age, as well as embryo/oocyte cryopreservation at breast cancer diagnosis followed by embryo transfer after endocrine therapy interruption, were significantly associated with an increased chance of pregnancy, reported Hatem Azim, MD, PhD, of the School of Medicine and Breast Cancer Center at the Tecnológico de Monterrey in Mexico, during the San Antonio Breast Cancer Symposium (SABCS).

Moreover, ovarian stimulation for cryopreservation, which precedes cryopreserved embryo transfer, was not associated with worse disease outcomes, Azim and colleagues found, with 9.7% of patients who underwent this procedure experiencing a breast cancer recurrence within 3 years compared with 8.7% of those who did not undergo the procedure.

The study "underscores the importance of early fertility counseling for young breast cancer patients," said Azim.

During a press briefing, Azim was asked about long-term safety, and said "it's a question of counseling the patient and her being at ease with the certainty or uncertainty we have with this approach. I think with these results in the short term, it makes us relatively more comfortable having this discussion."

He noted that the next analysis of this study will be in 2028 or 2029, "which by then should make us even more reassured."

SABCS discussant Hee Jeong Kim, MD, PhD, of the University of Ulsan's Asan Medical Center in Seoul, South Korea, agreed that fertility preservation counseling should start "as early as possible."

"Two-stage fertility-pregnancy counseling is essential for young breast cancer patients, incorporating oncofertility discussions at diagnosis and active considerations for pregnancy, including age, duration of therapy, option of interrupting endocrine treatment, and consideration of cryopreservation and embryo transfer," she said.

The primary results from the POSITIVE trial showed that patients with HR-positive breast cancer could safely pause endocrine therapy for up to 2 years to become pregnant without increasing their risk of breast cancer recurrence.

However, Azim observed that the safety of conceiving after fertility preservation and/or ART is unclear. Thus, he and his colleagues conducted a secondary analysis of the trial in order to evaluate fertility preservation and ART in these patients.

The POSITIVE trial included premenopausal women with stage I-III HR-positive breast cancer who desired pregnancy. Eligibility requirements included an age of 42 or younger at study entry, 18-30 months of prior endocrine therapy, and no clinical evidence of cancer recurrence.

Among the 497 evaluable participants who paused endocrine therapy to attempt pregnancy, 74% reported at least one pregnancy.

Azim and colleagues identified 179 patients who had undergone ovarian stimulation for embryo/oocyte cryopreservation at diagnosis and prior to enrollment, of whom 37.9% reported cryopreserved embryo transfer after enrollment. In addition, 215 patients used any form of ART after enrollment, of whom 37.2% underwent ovarian stimulation for in vitro fertilization (FIVET) or intracytoplasmic sperm injection (ICSI).

Pregnancy rates were 82.4% and 67.5% for women who underwent cryopreserved embryo transfer and FIVET/ICSI, respectively

In a multivariate logistic regression model that looked at the association of ART use and the chance of getting pregnant, Azim and his colleagues found that cryopreserved embryo transfer (vs no ART) was the only modality significantly associated with higher odds of achieving pregnancy (OR 2.41, 95% CI 1.17-4.95).

Age also played a significant role, as women younger than 35 had a 50% higher chance of achieving a pregnancy than women 35 to 39 (OR 0.50, 95% CI 0.29-0.86), and an 84% higher chance than women 40 to 42 (OR 0.16, 95% CI 0.08-0.29).

The cumulative incidence of pregnancy at 12 months was 64%, 54%, and 38% for patients ages <35, 35-39, and 40-42, respectively.

Kim suggested that on a global level, there are a number of barriers to fertility preservation -- including lack of insurance, financial burden, issues with referrals, as well as a lack of supportive systems in some countries -- and said these barriers "call for efforts to improve medical policies and communications, aiming to enhance support and informed decision making."

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