November 2010
American Association of Singapore: Singapore American

33

Vanessa always knew she wanted to have a house full of children someday. But in 2009, a diagnosis of breast cancer threw that plan into serious jeopardy. Vanessa's cancer was aggressive and she had to start chemotherapy right away. And the cancerkilling drugs could damage her ovaries, drastically reducing her chances of ever becoming pregnant.

So, the 33-year-old woman decided to take a chance on a promising procedure — freezing her ovarian tissue. If successful, she may be able to have children of her own in the future.

Until recently Vanessa would not have had this option. She is benefiting from a revolution in cancer care that is making fertility preservation a priority for patients who want to have children.


Keeping baby dreams alive for cancer patients

Fertility Preservation

Cancer patients and other women at risk of losing their fertility because of medical treatments can now help preserve their childbearing options through fertility preservation at Mount Elizabeth Hospital.

Fertility preservation, as explained by Dr. Kelly Loi, a specialist in fertility treatment at Mount Elizabeth Hospital, is a procedure to save a patient's ability to conceive with her own eggs in the face of premature menopause.

Women are born with a fixed ovarian reserve, referring to the number of eggs in the ovaries. This number falls from one million in each ovary at birth to 300,000 at puberty. It continues to fall until menopause when no eggs are left.

Who Can Benefit

Although cancer and cancer treatment can and/or greatly reduces the chances of female patients having children, it doesn't mean they don't have options. "The quality of life becomes increasingly important for this group of patients," said Dr. Loi. And being fertile and able to conceive is a significant concern.

A study led by Dr. Loi found that cancer patients here are interested in fertility preservation and emphasis should be placed on counseling patients on their options during the treatment planning process. Cancer specialists need to share this knowledge with their female patients so they are aware that they do have a chance to have children later.

Vanessa is one such example of a cancer patient who has benefited from such collaboration. Diagnosed with breast cancer, her oncologist recognized her risk of premature ovarian failure and referred her for fertility preservation. Vanessa opted to have her ovarian tissue preserved. Her ovarian tissue was collected by minimally invasive keyhole surgery. She went home on the same day as the surgery and started chemotherapy soon after.

Fertility preservation is also an option for patients with non-malignant diseases, such as women who must have an entire ovary removed or those requiring a bone marrow transplant.

What Methods are Available

Recent medical advances in fertility treatment now allow early stage female cancer patients and their partners the option of preserving eggs, reproductive tissue or embryos that can be used later for conception after cancer treatment is completed and the patient is given clearance by the oncologist.

If patients are married and in stable relationships, undergoing in vitro fertilization (IVF) to obtain embryos is ideal for fertility preservation. This is an established method with pregnancy rates of 20 to 30 percent following transfer of thawed embryos.

However, undergoing IVF involves hormonal

stimulation and takes time. This may therefore not be advisable for patients with certain hormone- sensitive tumors or where time is of the essence and cancer treatment cannot be delayed.

"What is new and promising for patients is freezing their eggs and ovarian tissue. These are new areas that are being rapidly developed and having increasing success," she said. "It's something that I strongly advocate myself. People have been looking at it for quite some time, but there have been success stories more recently. For freezing of eggs, there's been a new technique called vitrification - rapid freezing, where we aim to turn water into a glass-like state without ice crystal formation," she said. "This can be applied to embryos as well, but particularly for eggs it gives good results."

Pregnancy success rates using eggs that have gone through the vitrification process have doubled to about ten percent, while live birth rates from such eggs are about five percent. ParkwayHealth's doctors can also freeze ovarian tissue, which is collected through minimally invasive keyhole surgery as in Vanessa's case. The tissue is then stored in strips containing hundreds of eggs, and can subsequently be transplanted back into the patient to allow her a chance to get pregnant. Globally, there have been at least five live births reported using this method, the first in Belgium in 2004, Dr. Loi said.

Vanessa has completed her chemotherapy but has to continue medical treatment for another five years to decrease her risk of cancer recurrence. By that time, she will be in her late thirties. Her ovarian reserve may have declined significantly by then, especially due to her previous chemotherapy. However, with her ovarian tissue stored away, she still has a chance of parenthood even if she enters premature menopause.