Helping cancer patients retain their fertility

Cancer treatments sometimes come with a price – infertility and inability to have children. This is especially hard on women.

While men have the option to have their sperms frozen before starting chemo and radiation therapy or undergoing radical surgery, this doesn’t work for women for a number of reasons.

• Cryopreservation of female eggs did not really produce successful results. Human eggs do not fare well during the freezing and thawing process.
• Women usually produce only one mature egg at a time, once every menstrual cycle. While more eggs can be artificially induced to mature, as what is done in IVF, this process can be detrimental to the cancer patient’s health. In addition, the patient might not have the luxury to wait for the eggs to mature before treatment is initiated.

A new research funded by the National Institutes for Health (NIH) may just give female cancer patients some hope.  Researchers at Northwestern University’s Feinberg School of Medicine looked into the possibility of maturing and preserving eggs outside the body. As a first step, the researchers were already able to maintain human follicles, which are little sacs containing immature eggs, in the laboratory for 30 days. Furthermore, they were able to grown these cells to near maturity.

There are still two steps to finish before women can fully benefit from the technique. The second step is to induce the cells to undergo “meiosis”, a process wherein half of the genetic material is shed off in a cell called polar body while the other half is retained within the mature egg, ready for fertilization.

The process of meiosis has been already initiated in the lab by researchers at Stanford using stem cells, producing sperm-like cells. More work needs to be done before this technique can be applied to produce mature eggs but wheels are in motion. The Stanford study was also funded by NIH.

The third and final step is still to figure out how to cryopreserve mature eggs without causing damage. This is currently the focus of many research studies.

Currently, the most common method to help women preserve their child bearing potential is still to fertilize the eggs and cryopreserve the resulting embryos. However, this presents problems for women who do not have partners or whose partners are not willing to provide the sperms for fertilization.

Also in development is a technique which entails freezing part of or a whole ovary which can again later be implanted when the woman is ready for reproduction. However, this doesn’t work for those with ovarian cancer. There is also the danger that undetected cancer cells may be present in the ovarian tissue and that by introducing the said tissue later, new cancer cells are introduced back into the body.

According to Dr. Duane Alexander, M.D., director of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD):

“The new technique could provide an option for women and girls who have cancer and are not yet ready to start families. An additional benefit is that it will allow researchers to more closely follow the process by which immature eggs grow and mature. In turn, these observations may lead to new advances for treating other forms of infertility.”

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