Presentation of the most recent and advanced work in the rapidly progressing field of fertility preservation

Oct 18 2004

Each year approximately 50,000 women under the age of 40 are diagnosed with breast cancer. Treatments vary but most involve the administration of chemotherapeutic agents or radiation which can disrupt ovarian function or damage a patient’s eggs.

Because many of these women are still hoping to have children, researchers are seeking ways to protect patients’ future fertility that will not compromise their cancer treatment. This week, at the 50th Annual Meeting of the American Society for Reproductive Medicine, doctors and scientists from around the world are presenting the most recent and advanced work in this rapidly progressing field.

In the first study describing the use of aromatase inhibitors in breast cancer patients undergoing IVF, Kutluk Oktay, MD and his team at Cornell University compared three drug protocols for ovarian stimulation in breast cancer patients who elected to have IVF to freeze embryos before their chemotherapy. Because standard fertility drugs increase estrogen levels, they are not considered safe in breast cancer patients. Dr. Oktay and his team used two breast cancer drugs as fertility drugs in their study.

Thirty patients were assigned to one of three protocols: tamoxifen alone, tamoxifen plus low-dose FSH, or letrozole with FSH. Patients on the tamoxifen/FSH and letrozole/FSH regimens had more eggs retrieved and more embryos develop than those on the tamoxifen alone protocol.

Because breast tumor growth is influenced by estrogen, estrogen levels were tested in the IVF patients. Those who had taken tamoxifen/FSH had significantly higher peak estrogen levels than the patients who used tamoxifen alone or letrozole/FSH.

The researchers also compared the rates of cancer recurrence in the study group with a prospective control group of 30 patients similar in age and cancer stage who elected not to have IVF. After an average follow-up time of 19.3 months, breast cancer came back in three of the 30 patients who had IVF. This compares directly to a cancer recurrence rate of three in 30 in the control group.

Of the patients who underwent IVF, one has had an embryo transferred to a gestational surrogate resulting in the first pregnancy from a frozen embryo created in a tamoxifen stimulation cycle. Another patient in the letrozole group is at 13 weeks of pregnancy, the first ever resulting from using this drug in breast cancer patients. (Abstract No. O-2 Fertility Preservation in Breast Cancer Patients: A Prospective Controlled Comparison of Ovarian Stimulation with Tamoxifen and Letrozole for Embryo Cryopreservation. K.Oktay et al.)

Marian Damewood, MD, President of ASRM finds the work promising, “To young women facing the threat of cancer, the threat of losing their chances of having children is an additional cause of suffering. Dr. Oktay’s group has made significant progress in finding safe and effective ways to preserve future fertility for this group.”

Ovarian tissue freezing offers another means of preserving future fertility for women undergoing potentially sterilizing cancer treatments. For a woman who does not have a husband or partner at the time of her treatment, this method has the advantage of leaving open her future choice of the father of her children. However, researchers are concerned that grafting back preserved ovarian tissue may be dangerous if the tissue contains undetected malignant cells.

Doctors in Israel have developed methods for screening ovarian tissue for malignancies. First, ovarian tissue obtained through laparoscopy is prepared in slices for freezing. Then, very small portions are taken from each slice and analyzed for microscopic malignancies. If cancer cells or markers are found in the sample, the patient’s ovarian tissue is not frozen.

The methods used to test for each type of cancer are different. Ovarian tissue from leukemia and lymphoma patients is tested for specific chromosomal translocations; breast cancer patients’ tissue is stained for tumor antigens; and tissue from patients with Hodgkin’s lymphoma is examined pathologically. (Abstract No. O-289 Detection of Microscopic Metastasis of Solid Tumors and Hematological Malignancies in Cryopreserved Ovaries. Shai E. Elizur et al.)

“This work advances the goal of providing the best, individualized treatments to patients. Preserving fertility is a very important goal for many cancer patients, but the method chosen must be the safest. The techniques Dr. Elizur presents are essential to avoid transferring cancer cells back to patients who have completed treatment. The implications for testicular tissue cryopreservation and bone marrow transplantation are important, as well,” remarked Owen Davis, MD, President of the Society for Assisted Reproductive Technology.

http://www.asrm.org