P-366 Short- and long-term safety outcomes in patients undergoing fertility preservation (FP) with controlled ovarian stimulation prior to chemotherapy
Authors: Tsonis O , Dimitriou E , Zahed N , Raj R , Kopeika J 
Published: July 2024

Abstract

Study question
The Impact of pre-chemotherapy fertility preservation (FP) with controlled ovarian stimulation (COS) on mortality and complications in cancer patients

Summary answer
The 5-year survival was higher in women who proceeded with FP than those who did not.

What is known already
FP in the form of egg/embryo freezing is a well-established option to preserve fertility in patients requiring gonadotoxic treatment. This method introduces a slight delay in chemotherapy initiation, raising theoretical concerns about its impact on long-term patient outcomes. Additionally, safety concerns exist for estrogen-sensitive pathologies. However, data on safety outcomes, especially mortality and cancer recurrence in women undergoing fertility preservation, remain limited.

Study design, size, duration
This study utilized a prospectively collected database of 603 patients referred from the UK South and South East cancer network for fertility preservation to a tertiary Assisted Conception Unit between 2003 and 2019.

Participants/materials, setting, methods
All female patients attended the Fertility Preservation Service post-cancer diagnosis to discuss options. Patient demographics, stimulation details, and treatment outcomes were recorded. Living status was confirmed up to January 2024 through Health Record Registry. Data analysis included basic demographics, hazard ratios, and 5-year survival analysis, with a log-rank test comparing patients who received or did not receive fertility preservation treatment.

Main results and the role of chance
As many as 603 patients were counselled re: FP over the studied period. The biggest majority of patients n = 320 (53%) had a diagnosis of breast cancer, followed by 67 patients (11.1%) presenting with lymphomas. The majority of counselled patients (n = 340 (56.4%)) went ahead with fertility preservation. Mean age of participants was 32.7 with an average BMI of 24.6, average AMH of 19.2 pmol/L, and median AFC of 15. Short term complication was estimated at 2% of the sample. Successful stimulation was noted in almost all cases (cancellation rate 1.5%) requiring on average 14 days to complete the treatment. A short protocol was mainly used (98% of cases) with a median daily FSH injection at 300 IU/L and an average oocyte yield of 14. Mortality in patients who received fertility preservation was estimated and the respective hazard ratio was 0.74 (95% CI 0.47 to 1.15, p = 0.18). With regards to survival, the log-rank test yielded a chi-square value of 3.9 with 1 degree of freedom. The resulting p-value was 0.05, indicating a statistically significant difference in survival probabilities between patients who underwent fertility preservation compared to those who did not (p = 0.05).

Limitations, reasons for caution
Information on the cause of death was unavailable, limiting the ability to minimize bias and estimate disease recurrence. However, the young age of the patient population reduces the likelihood of death due to unrelated medical conditions.

Wider implications of the findings
The data suggests that fertility preservation with controlled ovarian stimulation is a safe option for cancer patients. This finding provides reassurance to patients considering this well-established fertility treatment, offering realistic chances of survival.

Trial registration number
not applicable