medwireNews: Women who undergo hormonal or nonhormonal fertility preservation procedures following breast cancer diagnosis are not at increased risk for relapse or breast cancer-specific mortality, Swedish study findings indicate.
Kenny Rodriguez-Wallberg (Karolinska Institutet, Stockholm) and co-investigators say their results “provide much needed additional evidence on the safety of [fertility preservation] procedures in women with [breast cancer] and may influence current health care practice to the benefit of young women with [breast cancer] who wish to preserve their fertility.”
The researchers note that although “[b]reast cancer is the most common indication for fertility preservation in women of reproductive age,” there are a lack of data on the impact that hormonal stimulation for fertility preservation may have on breast cancer prognosis.
To address this, Rodriguez-Wallberg and team reviewed data for 425 women aged 21 to 42 years with breast cancer who underwent cryopreservation of oocytes and/or embryos using hormonal stimulation (n=367) or cryopreservation of ovarian tissue without hormonal stimulation (n=58) between 1994 and 2017, and for 850 controls, matched for age, time of diagnosis, and region who did not undergo fertility preservation.
They report in JAMA Oncology that, after adjustment for country of birth, education, parity at diagnosis, tumor size, number of lymph node metastases, and estrogen receptor status, there was no significant difference in breast cancer-specific mortality rates between the women who did and did not undergo fertility preservation.
Specifically, the 5-year breast cancer-specific survival rates were 96%, 93%, and 90% in the women that underwent hormonal fertility preservation, nonhormonal fertility preservation, and no fertility preservation, respectively. At 10 years the rates were a respective 88%, 90%, and 81%.
These outcomes corresponded to nonsignificant adjusted hazard ratios (aHRs) of 0.59 for hormonal versus no fertility preservation and 0.51 for nonhormonal versus no fertility preservation.
In a subcohort of 723 women with sufficient data, the investigators found that there were also no significant differences among the three groups in adjusted rates of relapse.
In this case, the 5-year relapse-free survival rates were 89% in the women who underwent hormonal fertility preservation, 83% in women who underwent nonhormonal fertility preservation, and 82% in women who did not undergo fertility preservation, with nonsignificant aHRs of 0.81 and 0.75 for hormonal and nonhormonal fertility preservation versus none, respectively.
The corresponding relapse-free survival estimates at 10 years were 82%, 80%, and 73%.
Rodriguez-Wallberg et al conclude: “Women diagnosed with [breast cancer] during their reproductive years should be referred, when interested, for fertility counseling and provided with the available information on safety of the procedures that are offered.”
They add that “[f]uture research evaluating long-term safety of [fertility preservation] in young women with [breast cancer] should ideally include even longer follow-up,” given that the median follow-up times in the current study were 4.0 years in the women who received hormonal fertility preservation and 6.7 years in those who underwent a nonhormonal procedure.
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JAMA Oncol 2022; doi:10.1001/jamaoncol.2022.3677