Fertility preservation might be a bit more difficult for women with breast cancer who test positive for the BRCA gene mutation.
That was the conclusion of an analysis of two single-center studies that compared fertility preservation outcomes in two groups of women with early-stage breast cancer. Women in one group had tested positive for BRCA gene mutations, and women in the other cohort had tested negative. The findings were presented Sept. 9 at the European Society for Medical Oncology (ESMO) 2017 Congress, in Madrid, Spain.
Considered in the analysis were 29 patients who were BRCA-positive and 69 patients who were BRCA-negative. The median age of the BRCA-positive group was 31, while the median age of the BRCA-negative group was 30.
All of the women either underwent oocyte cryopreservation (OC), meaning that their eggs were extracted and frozen for possible use later, or ovarian tissue cryopreservation (OTC), which involves the removal and freezing of the outer layer of the ovary, which includes many eggs. All the women had these processes done before surgery and/or chemotherapy treatment.
Twenty-seven women underwent OC. Fewer eggs were able to be retrieved in the BRCA-positive group than in the BRCA-negative group (6.5 versus 10 eggs per patient), and fewer of those retrieved were able to be preserved (3.5 versus 6 per patient, respectively). Poor response rates (retrieval of four or fewer eggs) were recorded at a rate of 40 percent among BRCA-positive women, compared with 12.5 percent in BRCA-negative women.
For the patients who underwent OTC, the authors noted, “BRCA-positive patients had numerically lower oocyte density per (ovarian) fragment and per mm2 (cross-sectional area of the ovary) than BRCA-negative patients.”
Two BRCA-positive patients had egg transplants after chemotherapy. One of the women carried a healthy baby to term. In the abstract presented at ESMO, the researchers did not note the number of BRCA-negative patients who underwent egg transplants — if any — or the outcomes of those procedures.
While there was a difference seen in fertility preservation outcomes in patients with and without the BRCA mutation, there was no difference between women who had the BRCA1 versus the BRCA2 mutation.
Previous preclinical evidence has suggested similar findings regarding the potential negative impact that BRCA gene mutations can have on fertility preservation; however, even after confirmation via this analysis, researchers believe that further investigation is warranted.
“This is the largest study addressing fertility issues in BRCA-positive (breast cancer) patients. We observed a trend for reduced reproductive potential and performance of OC and OTC in BRCA-positive (breast cancer) patients. Further research efforts in this field are urgently needed,” the study authors wrote.