The most common and successful option for a woman with cancer is freezing an egg or embryo before undergoing chemotherapy or radiation. Once the patient decides she is ready to get pregnant, she is given estrogen and progesterone to prepare the lining of the uterus. The embryo is then thawed (or the egg is inseminated) and transferred into the uterus. Success rates specifically for cancer patients have not yet been studied. But in vitro fertilization (IVF) rates are around 50 percent for women younger than 35.