Читать книгу Assisted Reproduction Techniques - Группа авторов - Страница 97

Challenge: Fertility preservation in patients with cancer.

Background:

 Young patients with many cancers have excellent survival prognosis and should be promptly referred to explore their fertility preservation options.

 The effect of chemotherapy on ovarian function and fertility will depend on drug(s) used, dosage, duration of treatment, age of the patient and baseline ovarian reserve.

 Radiotherapy, particularly if directed to the pelvis, can affect fertility.

Management options:

 Multidisciplinary team approach.

 Fertility preservation options will be determined by the pubertal stage of the patient, baseline ovarian reserve, time available for fertility preservation and whether the patient is in a stable relationship with a partner who can offer sperm for the creation of embryos.

 Fertility preservation options are:prepubertal girls: ovarian tissue cryopreservation;postpubertal girls: controlled ovarian stimulation (COS) and oocyte storage; ovarian tissue cryopreservation; GnRHa co‐treatment during chemotherapy;women: COS and embryo and/or oocyte storage; ovarian tissue cryopreservation; GnRHa co‐treatment during chemotherapy;prepubertal boys: no established options;postpubertal boys: sperm banking (sperm obtained from masturbation, electro‐ejaculation or SSR);men: sperm banking.

 Ovarian tissue cryopreservation and transplantation: generally, no more than 50% of one ovary is removed for storage; storage and transplantation should be carried out in specialized centralized facilities.

 COS: requires approximately 2 weeks to complete treatment to the oocyte retrieval stage. COS can start at any stage in the menstrual cycle. However, if starting in late follicular or luteal phase, use an FSH only preparation (and not HMG) and start GnRH antagonist at the same time as starting the FSH injections.

 In women with estrogen receptor positive cancers, consider using antiestrogens (Letrozole or Tamoxifen) during ovarian stimulation. Consideration should also be given to gestational surrogacy to avoid high levels of circulating estrogens that can result from a pregnancy.

 GnRH agonist appears to be effective in providing some protection to the ovaries during chemotherapy. Therefore, it would be reasonable to offer a woman GnRHa treatment during chemotherapy. However, the evidence for protection of fertility is insufficient and needs further investigation.