What is oncofertility
The term oncofertility describes an area that connects oncology to reproductive medicine, with the aim of developing and applying new options for fertility preservation in young patients with diseases or treatments with risks to fertility.
A more recent concept of oncofertility refers to the use of more conservative therapies that manage to preserve fertility and provide the same chance of cure as radical treatment, especially in those neoplasms involving the gynecological tract, such as the cervix, ovary or endometrium.
Data reaffirm the growing importance of the area within oncology. In Brazil, about 19% of new cancer cases in women occur in patients up to 44 years of age, and 21% up to 49 years of age, a period considered fertile for about 90% of women. In the age group of 20 to 39 years, some of the most incident tumors are breast, uterine cervix and ovarian cancer, all of which can affect fertility.
How cancer patient fertility can be affected
Cancer and its treatment are not necessarily an impediment for patients facing the disease to have children. New techniques to preserve fertility and even strategies to combat the disease that are less harmful to the ability to reproduce are gaining ground. Therefore, the idea that treatment for certain types of cancer – such as breast, ovary and uterus cancer – unconditionally leads to infertility is no longer a reality.
Physicians should educate patients in this regard early on in treatment, as women who wish to have children need to express this interest and talk to the medical team about the options available to preserve their fertility.
The topic is also of interest to men who may have their reproductive capacity directly affected by some cancers or their treatments, such as prostate and testicular cancers.
Treatments that can affect fertility in women
Understand the effect cancer treatments can have on female fertility:
• Chemotherapy – Most chemotherapy drugs can damage a woman’s eggs. The intensity of this damage will depend on the age of the woman, the types of drugs and doses administered;
• Stem cell transplantation – usually involves high doses of chemotherapy and sometimes radiation therapy. In most cases, this procedure can permanently stop ovulation;
• Radiotherapy – high doses of radiation to the abdomen or pelvis can destroy some or all of the eggs, causing infertility or early menopause.
• Surgery – Hysterectomy, surgery to remove the uterus, is part of the treatment for some types of cancer, which prevents having a child. The ovaries may also be removed (oophorectomy) along with the uterus; and
• Hormone Therapy – Used in the treatment of breast and other cancers, hormone therapy can also affect a woman’s ability to have children.
Treatments that can affect fertility in men
Understand the effect cancer treatments can have on male fertility:
• Chemotherapy – cancer treatment during childhood/adolescence can damage the testes and their ability to produce sperm. The risk that chemotherapy will cause infertility varies according to the patient’s age, type of drug and doses administered;
• Hormone Therapy – Some hormone therapies used to treat prostate cancer can affect sperm production. These drugs can also cause sexual side effects, such as decreased libido and problems with an erection;
• Stem cell transplantation – as the treatment requires the patient to receive high doses of chemotherapy and sometimes radiation, it can permanently stop sperm production
• Radiotherapy – if radiotherapy is directed to the testicles, it can affect fertility. Even when a man has radiation therapy to treat a tumor in the abdomen or pelvis, the testicles may receive a dose of radiation sufficient to impair sperm production; and
• Surgery – types of surgery that can affect a man’s fertility are orchiectomy (removal of one or both testicles), prostate removal (affects semen production and ejaculation or damages the nerves that allow an erection), bladder removal (radical cystectomy, which also removes the prostate) and other procedures that may interfere with ejaculation, such as removal of lymph nodes from the abdomen.
Treatments to preserve reproductive capacity
There are several options, in men and women, that can be used to preserve fertility in cancer patients. The following stand out:
• Cryopreservation of embryos, oocytes and spermatozoa – consists in the conservation of cells by means of a cooling process and maintenance at about negative 190°C. At such low temperatures, there are no metabolic activities and the cells are in a state of suspension of their chemical reactions. The basic principle of cryopreservation is to maintain cell viability and function after thawing. It can occur at different times, preserving already fertilized embryos or sperm or even oocytes (cells that are the origin of the female egg); and
• Oophoropexy – surgical procedure aimed at displacing the ovaries from the radiotherapy field, usually above the pelvic cavity. It is used in cases of radiotherapy treatment in pelvic organs, such as cervical cancer.
• There are also experimental treatments that deserve attention:
• Cryopreservation of ovarian tissue – involves the removal of a portion of ovarian tissue (or even its entirety), with subsequent use of oocytes found in the tissue or immature follicles (later matured in the laboratory for in vitro fertilization); and
• Ovarian Tissue Transplantation – In this process, thawed ovarian tissue can be self-transplanted into the atrophied ovary or peritoneum (orthotopically). However, safety in this technique becomes a concern, due to the risk of disease recurrence with the introduction of cancer cells that may be present in the transplanted ovarian tissue.