The University of Sheffield is a research university based in the city of Sheffield in South Yorkshire, England. Scientists there reviewed 499 male cancer survivors between the ages of 18 to 55 in the immediate area who had banked sperm prior to undergoing invasive cancer treatments.
Men who have undergone treatments like chemotherapy or radiotherapy for cancer are routinely offered the chance to store their sperm. Men produce sperm throughout their life. However, the volume, motility, and quality of their sperm decline with age. Also certain cancers can cause men to have poor sperm quality prior to treatment. Upon diagnosis, nearly 40 percent of men with Hodgkin’s disease and 50 percent with testicular cancer will have low sperm counts. It is extremely difficult to predict which men will become infertile as a result of chemotherapy treatments.
Cryopreservation is a controlled procedure used to preserve samples intended for use at a later date. There are different cryoprotectants and cooling rates that can be used to cryopreserve, with varying degrees of stability and viability.
Semen can be frozen and used successfully. It can be used for donation in fertility clinics, or as a precaution related to risks associated to post-treatment infertility in order to insure the ability to still have biological children. Some sperm do not survive or are damaged during freezing. This means that after freezing there may be a reduction in count and quality.
The standard storage period for sperm is normally 10 years. This period can be exceeded only in certain circumstances, up to a maximum of 55 years. For human sperm, the longest reported successful storage is 21 years.
The study, funded by Cancer Research UK, found that more than a third of men who bank their sperm prior to cancer treatment did not attend a single follow-up appointment. The meetings are meant to assess fertility and options. Those who bank sperm don’t realize it can be disposed of after a decade if doctors cannot confirm ongoing infertility. Depending on the circumstances the samples can be prepped to be stored longer. Given sustainability and limited space, samples can only be stored for so long. Failure to attend follow-ups means the likelihood of sample disposal. Often the subjects don’t realize they have to update the cryopreservation clinics with up to date contact information. Otherwise they don’t receive reminders about appointments and the expiration of sample storage. Patients need to understand the consequences of not attending all appointments.