Authors: Kyle Orwig, PhD, Lillian Meacham, MD, and Kathrin Gassei, PhD
Fertility rates in male and female childhood cancer survivors (CCSs) are lower than rates in their siblings. The Childhood Cancer Survivor Study (CCSS) has shown that malesurvivors of childhood cancer are half as less likely to have achieved a pregnancy with their partner compared to their male siblings . Infertility is more than the reciprocal of fertility since itexcludes individuals who are not actively trying to achieve pregnancy. By definition infertility is the inability to achieve pregnancy after trying for 12 months. When rates of infertilitywere studied in the CCSS, 46% of survivors compared to 18% of siblings reported experiencing infertility . Risk of infertility was highest in those survivors treated withhigh dose alkylating agents (a type of chemotherapy), bleomycin (also a type of chemotherapy), testicular radiation > 400 cGy (a fairly low dose), or genitourinary surgery. However,using pregnancies as a measure of fertility or infertility limits one to waiting until a childhood cancer survivor has grown into an adult and has attempted to get pregnant to be able todiagnose this late effect of cancer therapy. In young adult males semen analyses can be performed after the completion of cancer therapy to determine if a male is able to producesperm. It is important to realize sperm production can still recover in some males years after the completion of cancer treatment.
The testes function to produce testosterone and to produce sperm. The Leydig cells that produce testosterone are fairly resistant to damage by cancer treatments . Leydig cellfunction can be assessed by measuring morning serum testosterone levels and LH levels. The germ cells, that produce sperm, on the other hand are very sensitive to chemotherapyand radiation. Semen analysis is the gold standard for assessing the ability to produce sperm but in males who are unable to provide semen, high FSH levels and low inhibin areassociated with impaired spermatogenesis.
Many regimens of chemotherapy and radiation therapy used to treat cancer or as preparative regimens for bone marrow transplantation can result in infertility in young adultsurvivors of pediatric and adolescent cancer. Semen cryopreservation is available as a fertility-preserving option for pubertal males, but currently, no fertility-preserving options areavailable for prepubertal boys who are not yet producing sperm. However, experimental techniques are currently being developed that may provide fertility options for patients thatcryopreserve testicular tissue prior to gonadotoxic treatment. Semen or testicular tissue cryopreservation should be offered prior to the initiation of cancer therapy with gonadotoxicagents that will leave the patient at risk for infertility.
|Commonly Used Procedures for Fertility Preservation||
|Experimental Procedures for Fertility Preservation|