Oncofertility

The field of oncofertility is focused on assisting cancer patients and survivors maximize their reproductive potential. Working together, oncologists and fertility specialists can address the impact life-saving cancer therapies have on fertility.

Cancer and Fertility

Advances in cancer therapies have led to increased survival rates, but surgery, chemotherapy and radiation therapy can all result in reduced fertility.

Gonadotoxic chemotherapy drugs and substances cause temporary or permanent damage to the ovaries and testes. These drugs impact the ovarian reserve – the number of egg-producing follicles a woman has in her ovaries – by destroying immature and/or mature follicles and resulting in early menopause. Radiation to the abdomen or pelvis can also damage ovarian follicles or the reproductive organs. Even radiation to certain areas of the brain can lead to infertility by disrupting hormone production.

Chemotherapy and radiation can also impact sperm count, sperm motility or sperm morphology leading to male infertility. Surgical removal of the testicles and nerve damage that limits ejaculation are other causes of infertility.

Infertility is an important quality of life issue for young cancer survivors and one that should ideally be addressed immediately following diagnosis. By referring patients to a reproductive endocrinologist prior to the start of cancer treatment, steps can be taken to preserve fertility options.

Oncofertility and Female Fertility Options

Depending on patient age and other factors, there are a number of female fertility options available to women before, during and after cancer treatment:

• Embryo cryopreservation – mature eggs are harvested before the start of cancer treatment and fertilized through in vitro fertilization (IVF). The resulting embryos are then frozen for later use. This technique offers the best chance for later pregnancy
• Egg cryopreservation – using ovarian stimulation, eggs (oocytes) are obtained and frozen for later use. The eggs are not fertilized before freezing
• Ovarian shielding –protects the ovaries and healthy tissue near the cancer site by shielding them from radiation exposure
• Ovarian transposition –this technique involves surgically moving the ovaries away from the radiation treatment site to reduce the risk of damage
• Donor eggs or embryos – women whose ovaries have been damaged during cancer treatment can use eggs harvested from a known or anonymous donor. The eggs are then fertilized with sperm from the woman’s partner, or a donor, with the resulting embryos transferred into the woman’s uterus through IVF. Donor embryos may also be transferred

Oncofertility and Male Fertility Preservation

Fertility preservation options are also available to young men facing cancer treatment. These options include:

• Sperm cryopreservation – sperm freezing or banking uses sperm that has been collected prior to the start of cancer treatment. The sperm is collected through ejaculation or from the testes or epididymis through a minor surgical procedure and retained for later use
• Gonadal shielding – this protects the testicles from any stray radiation particles resulting from treatment at other sites in the chest or abdoman

Experimental Fertility Preservation Options

The below experimental treatment options have shown promise for future use:

• Ovarian tissue cryopreservation –this procedure involves the removal and freezing of egg-containing ovarian tissue. The thin slices of tissue are then frozen and can later be thawed and transplanted back into the body
• Ovarian suppression –prior to the start of chemotherapy, injections of gonadotropin agonists are initiated and continued throughout treatment. These drugs help to slow ovarian activity and prevent egg maturation. There is some controversy as to the benefit of ovarian suppression in fertility preservation
• Testicular tissue freezing – during a minor biopsy procedure testicular tissue is harvested and frozen for later use. Considered the only potential option for young boys that have not reached puberty, the procedure remains experimental

Growing survival rates among young cancer patients emphasizes the need for fertility preservation. Oncofertility addresses the future fertility impact of cancer treatment in this population.