Risk-reducing Strategies, Including Fimbriectomy, in Women With a Germline Mutation Predisposing to Ovarian or Pelvic Cancer

• FIMBRIMENOP-2402 study aims to evaluate the long-term management of cancer risks in premenopausal women who have a genetic predisposition to tubo-ovarian or primary peritoneal carcinoma, such as mutations in BRCA1, BRCA2, RAD51C, RAD51D, or PALB2 genes. This study offers an alternative to standard preventive surgery (bilateral salpingo-oophorectomy or BSO) by exploring the use of fimbriectomy (removal of the fallopian tube's fimbria) followed by delayed oophorectomy (removal of ovaries at menopause). It's a pragmatic multicenter trial conducted across various medical centers, employing a non-randomized controlled preference design to compare two preventive surgical strategies: 1. Fimbriectomy followed by delayed oophorectomy (F-DO). 2. Bilateral salpingo-oophorectomy (BSO). The primary objective is to compare the long-term efficacy of two preventive surgical strategies : 1. Fimbriectomy followed by delayed oophorectomy (F-DO). 2. Bilateral salpingo-oophorectomy (BSO). As for the design of the study, participants choose their preferred surgical strategy during or after oncogenetic counseling, ensuring patient autonomy in decision-making. • Follow-Up: Long-term follow-up includes clinical assessments, data collection from medical networks, and integration with national health databases to track outcomes up to the age of 70. This is the first French comparative study in real-world settings and is classified as interventional research (RIPH1) under French regulations, given the need to validate fimbriectomy efficacy.

Sex

Female

Minimum age

35 Years

Maximum age

50 Years

Inclusion Criteria:

1. Woman between 35 to 50 years
2. Addressed to or followed in an oncogenetic counselling
3. Identified risk of tubo-ovarian or primary peritoneal carcinoma based on mutational status (BRCA1, BRCA 2, RAD51C, RAD51D, PALB2). The list of considered mutations may be extended during the study.
4. Written informed consent
5. Patient covered by the French "Social Security"

Exclusion Criteria:

1. Prior bilateral oophorectomy and/or bilateral salpingectomy for any reason (prophylactic surgery or other)
2. Personal history of ovarian, fallopian tube or primary peritoneal cancer
3. Menopause defined by

   • In women without prior chemotherapy If no prior hysterectomy: the absence of menses for at least 12 months, or FSH \> 20 UI/L with low estrogen level with no identified gynecological or endocrine explanation. Amenorrhea related to an intrauterine device, vaginal ring or estrogen-progestin pill will not be considered as menopause.

   If prior hysterectomy: FSH \>20 UI/L with low estrogen level (with or without vasomotor symptoms, genitourinary symptoms)
   * In women with prior chemotherapy: the absence of menses for at least 24 months
   * In all women with progesterone-loaded intra-uterine device (IUD): FSH \> 20 UI/L with low estrogen level
4. Inability to comply with medical follow-up of the trial (geographical, social or psychological reasons)
5. Patient under guardianship or curatorship

• DERIVEDSchoenen S, Mailliez A, Risbourg S, Decoupigny E, Vanseymortier M, Pasquesoone C, Le Saux O, Ray-Coquard I, Navarro AS, Bresson L, Thiebaut A, Antoni G, Bertrand N, Leblanc E, Narducci F, Le Deley MC, Martinez Gomez C. FIMBRIMENOP-2402 trial: evaluating fimbriectomy with delayed oophorectomy in patients with high-risk tubo-ovarian cancer. Int J Gynecol Cancer. 2026 Apr 18:104715. doi: 10.1016/j.ijgc.2026.104715. Online ahead of print. PMID 42140840