Successful Fertility Preservation in a Case of Low-Grade Endometrial Stromal Sarcoma: A Multidisciplinary Approach Through the Oncofertility Network.

Low-grade endometrial stromal sarcoma (LGESS) is a rare disease, accounting for less than 1% of all uterine malignancies. Standard treatment is total hysterectomy and bilateral tubal oophorectomy, although fertility preservation may be desirable because of the young age of onset. We document a case of fertility preservation in a 27-year-old nulligravida diagnosed with LGESS, which not only enabled the successful birth of two live infants but also underscores the efficacy of a multidisciplinary approach to patient treatment through the Hyogo Oncofertility Network (HOF-net). The patient underwent laparoscopic removal of a lesion initially suspected to be either a uterine myoma or an adnexal tumor. Through the HOF-net, a pioneering collaboration among patients, oncologists, and fertility specialists, she was connected to our department with the aim of achieving pregnancy in the future, even amidst her cancer diagnosis. Following the surgery, and during a medically advised period of contraception, assisted reproductive technology with the double stimulation (DuoStim) method was utilized to cryopreserve six embryos, followed by high-dose progestin therapy to mitigate the risk of cancer recurrence. Once the contraceptive mandate had been concluded, the implantation of the first thawed embryo during a hormone replacement cycle led to a viable pregnancy and the subsequent birth of a healthy child by cesarean section. Similarly, during the contraceptive period, after undergoing high-dose progestin therapy, a second thawed embryo transfer was performed, resulting in a successful pregnancy and the birth of a second child. Subsequently, she underwent a total hysterectomy and bilateral salpingectomy with preservation of both ovaries at another hospital 39 months after the initial surgery. No recurrence or residual disease was observed. The necessity for comprehensive informed consent was underscored by the potential for LGESS recurrence. Furthermore, the efficient coordination facilitated by the HOF-net enabled swift access to assisted reproductive services, aligning with the patient's primary healthcare plan. This case highlights the critical role of early engagement with assisted reproductive technologies and a multidisciplinary treatment strategy in facilitating successful outcomes for patients with LGESS, demonstrating the feasibility of fertility preservation in managing this condition.