Currently, available options for preserving fertility are cryopreservation of embryos, oocytes, ovarian tissue and treatment with gonadotropin-releasing hormone (GnRH) analogs [1]. However, ovarian tissue cryopreservation and subsequent transplantation should be avoided owing to the risk of cancer reimplantation, and GnRH analogs can only be used in cases where at least one ovary remains. Therefore, the only option for patients with ovarian cancer who require oophorectomy is oocyte or embryo cryopreservation.

Transvaginal ultrasound-guided oocyte retrieval for oocyte or embryo cryopreservation has limitations. There is a potential risk of malignant spread secondary to cancer cell spillage by puncture of the tumor mass. The tumor can obscure the view of normal follicles, thereby preventing optimal oocyte retrieval. There are cases where the follicle is near the tumor making aspiration difficult, or where the tumor mass is near the vagina in the way of aspiration. In contrast, during a debulking operation for ovarian cancer, careful oocyte retrieval using a laparotomic approach can be performed without penetrating the tumor and without causing cancer cell spillage [23456].

In this report, we outline a successful case of oocyte retrieval performed via laparotomy during debulking surgery, to prevent the possibility of rupture and cancer cell spillage that is associated with transvaginal oocyte retrieval.

In May 2014, a 21-year-old nulliparous woman was referred by her gynecologic oncologist for fertility preservation prior to a second debulking surgery. Two years earlier (October 2012), she had undergone a fertility-sparing operation including right salpingo-oophorectomy, left ovarian tumorectomy, omentectomy, total splenectomy, cholecystectomy, appendectomy, and diaphragmatic peritonectomy. Pathologic findings indicated an immature teratoma in the right ovary and the fallopian tube, as well as teratoma implants with gliomatosis peritonei in the left ovarian mass, uterine wall, peritoneum, omentum, appendix, spleen, gallbladder, and diaphragm. The residual tumor size after the initial staging operation was <0.1 cm. The final diagnosis was immature teratoma of the ovary classified as stage IIIC according to the International Federation of Gynecology and Obstetrics. The patient underwent four rounds of adjuvant gonadotoxic chemotherapy (bleomycin, etoposide, and cisplatin) up to March 2013. During the chemotherapy, a GnRH agonist (leuprorelin acetate; Leuplin, 3.75 mg; Takeda Chemical Industries, Osaka, Japan) was administered monthly to minimize chemotherapy-induced gonadotoxicity. A follow-up computed tomography was performed at six monthly intervals. Approximately two years after the initial surgery, the patient was strongly suspected of having a recurrent ovarian immature teratoma following identification of a 4-cm multicystic lesion by using computed tomography and magnetic resonance imaging. Her CA-125 level was normal (13 U/mL). The gynecologic oncologist and reproductive specialist concluded that the optimal treatment option for the patient was oocyte cryopreservation and removal of the remaining ovary. At every step of the decision-making process, the patient received expert counseling and was given the opportunity to make active decisions about preserving her fertility.

Upon her first visit to the fertility preservation clinic, the patient was on day 25 of her menstrual cycle. Ultrasonography examination showed the left ovary with five antral follicles and an ovarian tumor. Basal hormone levels were measured on the same day: luteinizing hormone, 2.83 mIU/mL; follicle-stimulating hormone, 2.52 mIU/mL; progesterone, 3.25 ng/mL; estradiol, 64 pg/mL; and anti-Müllerian hormone, 1.46 ng/mL. Although the patient was in the luteal phase, ovarian stimulation was initiated that evening with gonadotropin (Gonal-F; Merck Serono, Rockland, MA, USA) at a dose of 300 IU/day; a total of 2,400 IU was administered over eight days. Despite the controlled ovarian stimulation (COS), the patient's next menstrual cycle began on stimulation day 4. A GnRH antagonist (Cetrotide, Merck Serono) was administered four times on stimulation days 6 to 9. Oocyte maturation was induced with 250 µg of recombinant human chorionic gonadotropin (hCG) (Ovidrel; EMD Serono, Rockland, MA, USA) after the mean diameter of the leading follicle had reached 18 mm. The patients' hormone levels were determined on the hCG triggering day: estradiol, 439 pg/mL; and progesterone, 0.86 ng/mL. The operation was scheduled for 36 hours after triggering oocyte maturation by hCG.

Laparotomy showed that the stimulated enlarged left ovary was intact with no rupture. We had planned to perform oocyte retrieval within a pouch; however, this was not possible because of adhesion around the ovary. Therefore, we performed oocyte retrieval carefully without a pouch in the operation field. All visible follicles were aspirated using a 5-mL syringe with an 18-gauge needle before starting the surgical procedure (Fig. 1A). After aspiration, buffer solution including Ham's F-10 nutrient mixture (Gibco Life Technologies, Breda, The Netherlands) and 40 IU/mL of heparin was supplemented. And then, we immediately performed ex vivo oocyte retrieval on the excised ovary to obtain additional oocytes using syringe prefilled with 1 mL of buffer solution (Fig. 1B); however, only a small amount of blood was obtained. Before oocyte retrieval, 10 follicles had been observed on ultrasonography; nine oocytes were obtained including eight mature (metaphase II) oocytes and one oocyte in metaphase I. For oocyte cryopreservation, oocytes were denuded from cumulus cells using hyaluronidase. After denudation, the oocytes were washed several times to eliminate hyaluronidase or other cell fragmentations. After preparation, the eight mature oocytes were cryopreserved by performing vitrification.

A complete debulking surgery was performed including left oophorectomy and multiple peritoneal seeding nodule resections on the uterine serosa, mesentery, and bowel serosa. The final pathology confirmed mature cystic teratoma of the left ovary, and multiple seeding nodules showed teratoma with gliomatosis peritonei. Follow-up imaging six months after the debulking surgery without additional chemotherapy showed no recurrence of the tumor as compared with immediate postoperative imaging. It was the patient's intention to try to become pregnant using the cryopreserved mature oocytes in the future.

To date, five case reports of oocyte retrieval from a tumor-affected ovary during laparotomic oophorectomy have been published [23456]. However, this is the first case in which a random-start COS protocol was applied in an ovarian cancer patient who required debulking surgery (Table 1) [23456].

Among the previous case reports, immature oocytes were retrieved from tumor-affected ovaries in three patients, after which in vitro maturation was performed [234]. In vitro maturation without COS has some benefits, because the safety of ovarian stimulation in a patient suspected of ovarian cancer prior to surgery has not been fully established; however, few oocytes are aspirated from unstimulated ovaries, and immature oocytes at germinal vesicle stage frequently fail to complete maturation in vitro.

In the other two reports, patients had undergone oocyte retrieval after a conventional COS protocol [56]. Because conventional COS protocols require 2 to 5 weeks depending on the patients' menstrual cycle, conventional COS is not optimal for emergency fertility preservation in cancer patients. Several recent studies have shown that a random-start protocol has a comparable outcome to a conventional protocol [78]. Using a random-start stimulation protocol, a sufficient number of mature oocytes can be retrieved within two weeks. Therefore, if a gynecologic oncologist makes an early referral to a reproductive specialist and if fertility preservation is discussed at the time of planning the cancer treatment, young women with ovarian cancer who require oophorectomy could have an opportunity to achieve parenthood.

Only one out of five patients in the previous case reports had undergone in vivo, rather than ex vivo, oocyte retrieval. Ex vivo retrieval has the benefit of minimizing possible spillage of cancer cells. However, the interruption of blood supply to resected ovaries could cause cell injury and deteriorate the quality of retrieved oocytes even if the time between oophorectomy and ex vivo oocyte retrieval is short. Therefore, we assumed that in vivo oocyte retrieval was optimal for minimizing oocyte damage, and hence attempted to retrieve as many oocytes as possible using this method.

We planned to perform oocyte retrieval within a pouch, but this procedure was not possible due to the adhesion around the ovary. Although we performed oocyte retrieval carefully without a pouch in the operation field with no spillage of fluid grossly into the abdominal cavity or elsewhere, we could not be confident that there was no microspillage of follicular fluid or cancer cell adjacent to the follicles. According to a previous study comparing patients with ovarian cancer stage IA to those with IC associated with intraoperative gross rupture of ovarian capsule, the difference in survival was not significant [9]; therefore, we can speculate that possible microscopic spillage has no significant influence on the prognosis of disease. However, there is no doubt that the utmost effort should be made to prevent spillage during aspiration.

Great reproductive outcomes for ovarian cancer survivors have been reported in the literature [1011]. Early counseling, a collaboration between the oncologist and fertility specialist regarding fertility preservation, and prompt initiation of treatment are important for achieving successful outcomes. Furthermore, a cautious approach with individualized treatment and counseling about pregnancy outcome, disease outcome, survival rate, and life expectancy are necessary.

In summary, we report a case of successful random-start COS and in vivo oocyte retrieval from a tumor-affected ovary during the laparotomic oophorectomy. This is the first case study in which random-start COS and in vivo oocyte retrieval were performed. Our study provides hope for patients with ovarian cancer and encourages health care providers to consider oocyte cryopreservation from tumor-affected ovaries as a feasible and safe procedure.