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“O sucesso do tratamento de fertilização assistida não se restringe ao teste de gravidez positivo. Muito mais que isso, é a garantia de que a mãe e o bebê permanecerão saudáveis desde o início dos procedimentos até o nascimento da criança. Afinal, de nada adianta alcançar rapidamente a gravidez única, gemelar ou até mesmo tripla, se o tratamento e a gravidez provocarem complicações que levem ao comprometimento da saúde do bebê e da mãe durante o tratamento a que estiver sendo submetida”
Dr. Arnaldo Schizzi Cambiaghi

Preservation Of Fertility In Cancer Patients

12 de setembro de 2011
Home » IPGO Inglês » Preservation Of Fertility In Cancer Patients

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The diagnosis of cancer is considered one of the most devastating news in a person’s life. On the one hand, this reality causes panic to think of the future that lies ahead; however, the subsequent news that the treatments for this disease are increasingly effective may bring some comfort. When determining what type of treatment will be subjected to the patient, particularly for prepubertal children, adolescents, young men and women who have no children and still desire to have them, one of the most important considerations is: what will be the damage to fertility after recovery? It is estimated that, in the near future, one in every 250 adults will be a survivor of cancer treatments, since radiotherapy, chemotherapy, in conjunction with surgery, can cure up to 90% (1). This increases the responsibility of the oncologist since not considering this important detail might create a very frustrating future for the patient.

For women, it is estimated that annually 650,000 are affected by invasive cancer and 8% of them (52,000) are under 40 years old. It is estimated that one in 52 women will get cancer before the age of 39 (2,3). Every year more young women have cancer. An annual increase of 0.3% of cases has also been registered. The cure rate is increasing: 0.6% per year. Therefore, it’s important to think about the future fertility of these patients (4).

Radiotherapy, when performed in the lower abdomen, may damage or even destroy the ovaries, depending on the size and location of the tumor and the intensity of irradiation required for the cure (5). When this occurs, the woman stops producing hormones and enters menopause, preventing pregnancy with her own eggs. The same can occur with chemotherapy (6), depending on the drugs used and the doses needed to cure the disease. In addition to eliminating the tumor, it may also impair the ovarian function (7). The castrating surgeries are often the best option to cure the woman, but could forever define the future of the infertile woman. The same considerations apply to men. It is important that the physician treating the cancer patient has technical knowledge on fertility preservation, in order to ensure that, after curing their patients, they are able to have children and build their families.

Techniques for fertility preservation

In the man

Freezing semen

It is a process performed with well-established techniques and reliable results. Semen should be collected through masturbation, preferably in several samples. It will be frozen at -196oC, stored indefinitely, and thawed and used when appropriate.

Freezing testicular tissue

Although freezing semen is a simple option and easy to perform, freezing testicular tissue may offer a long term option, especially in cases of some tumors affecting the quality of semen (8,9). It is still an experimental technique, but can sometimes be the only option. It is hoped that in the future, with advanced research on the use of stem cells, the technique of freezing testicular tissue can be an interesting alternative.

Observation

When there is an urgency for the initiation of cancer treatment, at least one semen sample should be frozen.

There are questions that should be answered by the doctor to the patient, his parents or guardians (if a minor), before the start of a cancer treatment:

1) Will the treatment affect the fertility of the man or boy? If the answer is “yes”, what is the best technique to preserve fertility?

2) How and when can the patient know whether he is fertile or not after the completion of the treatment? Are there tests for this?

3) If fertility is not preserved, are there alternatives so that he may have children in the future?

4) If the semen or testicular tissue is frozen, is there a time limit for its use?

5) Will there be changes in sexual desire?

6) Are there risks to the pregnancy or the child when he decides to have children?

7) What specialized clinics may indicate the best methods to preserve fertility?

In the woman

Girls are born with a limited number of eggs. The quantity of eggs gradually decreases from the first period until menopause when there are no longer eggs available to be fertilized (10,11). Radiotherapy and chemotherapy tend to further accelerate this loss of reproductive capacity.

New techniques have provided hope to preserve or restore fertility in girls and women who are undergoing cancer treatments. These include the freezing of embryos, ovarian tissue, eggs, and ovarian transposition in the case of radiotherapy.

Embryo freezing

Through in vitro fertilization, the ovary is stimulated with hormones, the eggs are retrieved, and then they are fertilized in the laboratory. The developed embryos will be frozen in liquid nitrogen at -196oC, staying there indefinitely. It is considered a good technique being effective and providing pregnancy rates around 40% (12). However, it is restricted to patients who do not require immediate cancer treatment and tumors that are not affected by hormones. In addition, women should already have a partner with which to start a family. Another concern is the fact that embryos are legally and ethically considered living beings and, therefore, in no event may be discarded. If there is no interest for one of the partners in keeping the frozen embryos or no desire to use them for future pregnancy, they may not be claimed by the other, which can often turn into legal disputes. The freezing of ovarian tissue and eggs do not have this obligation.

Freezing of ovarian tissue

It can be a great alternative for children who have not yet reached puberty and thus do not yet have eggs to be frozen, and for patients who cannot be subjected to ovulation induction with hormones. Through video laparoscopy, a minimally invasive surgical technique, a portion of an ovary is removed. This tissue is frozen, remained so until the right time to be reimplanted. There is no predetermined period. The tissue may be fragmented or not, and can be reimplanted in the pelvic region, on the other ovary, near the fallopian tubes (topic), or in different locations like the abdominal wall or arm (heterotopic) (13). Under such conditions, for pregnancy to occur, ovulation induction drugs commonly used in in vitro fertilization treatments are usually needed. It is an option that offers small success rates, but may be indicated when there is no other appropriate alternative.

Egg freezing

It is a very important technique which provides good results for future pregnancy. Its advantage, when compared to embryos, is that they are cells; therefore, if no longer needed, they may be discarded. The patient should undergo treatment for ovulation induction similar to in vitro fertilization with the retrieval of eggs and subsequent freezing. In these cases, there are two possibilities for the same purpose. If the patient’s tumor needs chemotherapy and can wait three to five weeks for oncological treatment, she will receive drugs for ovarian stimulation to allow for a greater number of eggs to be frozen, because more eggs guarantee better results in the future. The type of medication will depend on the tumor whether being sensitive or not to the estrogen hormone that can become elevated in this type of treatment and worsen the course of the disease. However, it is important to know that for these cases there are appropriate strategies for ovulation induction, that shortens the period of induction and tumor exposure to this hormone. But if the patient cannot receive conventional hormones, other “weaker” hormones may be used that can generate a smaller number of ova or even use a natural cycle without drugs. In some specific cases the eggs may be matured in the laboratory by a special technique (in vitro maturation) later to be frozen (14,15). This will cut down the exposure time to estrogen even more.

Transposition of the ovaries

In those situations where radiotherapy is necessary in the pelvic region, the ovaries may be affected directly and have its ovarian reserve impaired. To avoid this proximity of the ovaries with the “probes” used in radiotherapy, a minimally invasive surgery (video laparoscopy) can be performed to place the ovaries behind the uterus during the treatment period or in another location away from the place that will be affected by radiation. Since radiotherapy does not harm the uterus that serves as “shield” protector of the ovaries, they will be protected (16,17). After the treatment, by the same surgical technique, the ovaries may be placed back in their original location.

There are questions that should be answered by the doctor to the patient, her parents or guardians (if minor) before the start of a cancer treatment:

1) Will the treatment affect the fertility of the woman or girl? If the answer is “yes”, what is the best technique to preserve fertility?

2) How and when can the patient know whether she is fertile or not after the completion of the treatment? Are there tests for this?

3) If fertility is not preserved, what are the alternatives so that she can have children?

4) If there is ovarian failure (menopause due to the treatment), what will be the symptoms? Is there a treatment for this?

5) After completing the treatment, how long will it take for her period to return? If she is not menstruating, is it necessary to use contraceptives or hormones to avoid getting pregnant?

6) Will there be changes in sexual desire?

7) Is pregnancy safe after treatment? If it is a positive response, how long should the patient wait to become pregnant?

8) Are there risks to the pregnancy or the child if she becomes pregnant?

9) Where can the patient find clinics in Human Reproduction specialized for this type of treatment?

 

 

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