Over the last 40 years there has been a visible progress in the cancer treatment. The survival rate of cancer patients has significantly increased. Treatment of cancer is a huge stress for the patient, but also for all of their cells – including reproductive cells. Modern medicine provides a number of opportunities through which it is possible to preserve fertility, despite of the use of anticancer therapy. Taking the appropriate steps at the moment of diagnosis, can be of great importance in the future. The American Association of Clinical Oncologist (ASCO) recommends that every patient at reproductive age, having to join the fight against cancer, was informed about the effects that chemotherapy and radiation have in the field of fertility, as well as about opportunities for patients who after recovery desire to have children.
The term ONCOFERTILITY means a series of procedures that help preserve fertility in patients diagnosed with cancer. During the period of treatment (radiotherapy or chemotherapy), the most damaging effects has irradiation of areas surrounding the ovaries and testes. Production of sperm i.e. male reproductive cells, after complete recovery may return, but it is otherwise in the case of ova, loss of which can unfortunately be complete. Ovaries are extremely sensitive to cytotoxic drugs that are used during therapy and whose task is to fight against cancer.
BEFORE ANTICANCER THERAPY
The basic method of protecting fertility before starting cancer therapy is cryopreservation. This term describes the method by which a long-term storage of frozen reproductive cells is possible. Biological material, transferred to the laboratory, is prepared according to specific methods. Freezing process is completely safe and controlled. It is performed in the presence of special substances (cryoprotectants) whose function is to protect cells against damage.
The loss of fertility can be prevented by:
Semen freezing is the basic method that allows to protect genetic material of the future father. Freezing procedure is not complicated. There are no restrictions on the number of portions of semen, which patients can freeze. The semen is stored in liquid nitrogen (stable conditions -196 degrees Celsius) without negative effects for many years. Thus the frozen material, depending on the parameters, can be used for different procedures: in vitro fertilization (fertilization of oocytes using ICSI – direct placing of a spermatozoon in oocyte in the laboratory), and intrauterine insemination, which is a procedure of painless direct administering of spermatozoons of the best quality into the uterus. The aim of these procedures is to reach pregnancy. If there is no sperm in the ejaculate, it is possible to freeze the testicle tissue taken under anesthesia at the time of biopsy.
This is the most effective method to protect the chances of having children in women in whom treatment of cancer can lead to the loss of ovarian function. This option is available only if the patient has time to prepare for the surgery under the care of a physician treating infertility. It is necessary to have hormonal stimulation i.e. taking the right hormonal drugs prior to the scheduled chemotherapy or radiotherapy. Cells, obtained as a result of stimulation, are taken from the patient under anesthesia, and then subjected to extracorporeal fertilization, which results in embryos.
FREEZING OF EMBRYOS ARISING UNDER IN VITRO FERTILIZATION
The female reproductive cells (oocytes) are also obtained as a result of hormonal stimulation. Advances in the field of cryopreservation (introduction of new methods of oocytes freezing – vitrification) may lead to the replacement of embryo freezing by oocetyes freezing. As a result of vitrification of oocytes their survival rate is of 85%. Still, the embryo freezing is the method recommended by specialists in the treatment of infertility.
FREEZING OF OVARIAN TISSUE
Collection of ovarian tissue is performed using a laparoscopic technique. Tissue sections are subjected to cryopreservation and, after recovery from cancer, can be implanted again. This process is complicated; however, gives hope to restore ovarian function and the possibility of becoming pregnant after the treatment. Unfortunately, like any other, also this method has its limitations. First of all, they relate to tissue transplant survival and the time during which it can function. The activity of such tissue is also reduced, so transplant patients are recommended to take hormonal stimulation and in vitro fertilization. Still, it may be a method by which we can increase the chance of getting long-awaited offspring.
There are also ways to protect fertility, which are not related to freezing, but their efficiency is much lower. These include ovarian and testicular protection at the time of irradiation or pharmacological treatment, such as the inhibition of ovarian functions.
Selection of the appropriate method to protect fertility should be deeply thought over by you and consulted with a doctor and oncologist specializing in the treatment of infertility. It should also be dependent on:
- the type of treatment – chemotherapy, radiotherapy, and other
- the time remaining to the beginning of treatment
- tumor type
- the patient’s age
CANCER IN CHILDREN AND SUBSEQUENT PARENTING
The topic of fertility preservation should be presented to the parents of children diagnosed with cancer. Though it is psychologically difficult issue, it should be routinely presented by oncologists, as it allows to have children in later adult life. Girls at prepubertal age have no hormonally active ovaries, so the risk of damage by anticancer therapy is lower than in women at reproductive age. The best prophylactic solution is to collect laparoscopically ovarian tissue and freeze it, then the use of it at childbearing age for transplant.
Semen freezing is, however, a method that gives hope for being the father in adulthood for boys suffering from cancer if their reproductive system is already active. Children prepared for such procedures should be covered by a specialized psychological care, due to their immaturity and emotional difficulties in understanding the measures in place. The responsibility therefore lies with parents. The right decision will have influence on whether their daughters and sons in the future will be able to enjoy the happiness of their children.
DURING THE ILLNESS
Patients diagnosed with cancer should not start conscious efforts to conceive a child. This does not mean that the patients, during therapy, should keep total abstinence. However, be careful so that cohabitation would not cause pregnancy. This requires the use of birth control (condom use or complete hormonal contraception). The form should be consulted with a gynecologist, after a prior visit to the oncologist.
GENETIC ASPECTS – CANCER AND FERTILITY PROTECTION
Cancerous disorders as well as fertility problems may be of genetic origin. The development of civilization, increasing concentration of factors which may result in the development of cancer and methods used in cancer therapy often do not remain indifferent to the structure of genetic material of patients. This may result in miscarriages or difficulties to get pregnant. A diagnosis of genetic disorders is extremely difficult, but not impossible. After treatment one should take into account any relevant counseling and diagnostics that can determine the possibility of taking procreation.
CONVERSATION ABOVE ALL
Studies conducted in university centers involved in the treatment of cancer patients, confirm that the mere awareness of the possibility of having children after recovery gives a better chance of successful treatment of cancer patients. It is worth, therefore, to ask your doctor or oncologist for a conversation about the possibility of becoming pregnant after treatment for cancer. This applies to both women and men equally are responsible for obtaining children. It is advised contact the nearest infertility treatment centre in order to obtain information on the protection of fertility.
The list of tests for candidates for the donor of reproductive cells collected in order to secure fertility for the future (before freezing of semen / testicle tissue / ovarian tissue):
Furthermore, additional examinations:
- HTLV – 1 ( human T-lymphotropic virus type 1) – should be made by the patients, who come from high-incidence areas or whose sexual partners or parents originate from those areas (North and South America, Caribbean);
- Trypanosoma cruzi – after the patient’s travel to the countries of Central or South America, to two weeks after returning from a trip or up to 40 days after blood transfusions made in the countries of Central or South America;
- Malaria – after the patient’s travel to tropical countries, where there is malaria (please make sure that there is a risk in a given region using, for example, the website of Military Medical Institute: www.medycynatropikalna.pl/info/27/malaria_profilaktyka):
– A quick test for malaria – up to 40 days after returning from a trip, if there are no symptoms, and a year after returning from a trip, if there were episodes of fever.
– Smear – up to 40 days after returning from a trip, if you have episodes of fever.
Results of vurological tests are valid for 2 weeks.
dr n. med. Jarosław Janeczko
mgr inż. Michał Zalewski