"Doctor, I want to freeze my eggs." Looking at the young face in front of me but slowly spitting out words that didn't match her age, I was stunned for a while. Miss T, who is 24 years old, was diagnosed with breast cancer and came to the fertility clinic for egg freezing consultation. At that moment, the life marquee in my mind turned a few times. I recalled being a trainee doctor at the same age as her. I only need to focus on the knowledge from school, and rarely think about what I should have and what should be in the future.
She and I are different, contrasting with the young girl who told me what she wants in life, even in the face of a horrible disease. After discussing with her, because the chemotherapy would start in 2 weeks, we need to start our plan as soon as possible.
Fortunately, because of her young age, Ms. T has a nearly 80% chance of live birth if she retrieves 10 mature eggs. At the same time, her AMH is 5 ng/mL, which means that if she is stimulated well, she can achieve her goal once. However, due to the lack of time, we cannot start the treatment until the period comes. So we use the so-called Random start treatment. Ms. T also mentioned that she is worried that hormonal stimulation will affect breast cancer. Therefore, we also use the oral drug Letrozole at the same time to reduce hormonal affection. After a total of 10 days of stimulation, the hormone before the trigger shot was 2513 pg/mL. Finally, 23 eggs were retrieved and 18 mature eggs were freezing, which achieved the goal we discussed at the beginning.
Since 2006, breast cancer has ranked first in female cancer in Taiwan. The proportion of breast cancer patients younger than 40 years old is 16.6%, and the younger than 35 years old is 9%, which is 4.5 times that of the United States. Most are hormone-positive patients. With the cancer treatment advanced, the five-year survival rate of young breast cancer has exceeded 60% to nearly 70%. Therefore, the goal of treatment has changed from simple survival to considering the quality of life, and fertility is one of them.
However, many of these patients of reproductive age require chemotherapy and hormonal therapy in addition to surgery. In addition to the damage of chemotherapy drugs to ovarian function, the hormonal treatment also takes five years, which is enough to reduce ovarian function. According to a retrospective study in the United Kingdom in 2018, people under the age of 39 who developed breast cancer had a 70% lower chance of having children than those who did not have cancer at the same age. Fortunately, while cancer treatment has progressed, the field of reproduction also kept on. The American Cancer Society published the first clinical guidelines on fertility preservation for cancer patients in 2006, and began to recommend that clinicians discuss with patients of reproductive age before starting treatment. The effect of subsequent treatment on fertility and the possible way of preserving fertility - embryo freezing.
In 2013, clinical guidelines recognized the benefits of egg freezing as a clinically viable option in addition to embryo freezing, offering many women without a partner or religious (some religions believe that embryos are life) the opportunity to preserve their fertility.
It is undeniable that after consultation on egg freezing treatment, the decision to freeze eggs or not depends on multiple factors - in addition to the individual's future fertility willing, the prognosis of the disease itself, the impact of chemotherapy drugs on ovarian function, and the benefits after egg freezing are also considered by most people.
As for reducing the hormonal impact and buying time, there are currently several clinical methods: displaying the benefits of pre-storage eggs and the chance of trying a natural pregnancy for one year after five years of cancer diagnosis. Most of the women who come to the clinic for consultation have only 2-4 weeks from the diagnosis to the chemotherapy. In the traditional egg retrieval course, there is only one chance to retrieve the eggs. As young as Miss T, the age of diagnosis is less than 35 years old, due to the good ovarian function and the quality of eggs, it is generally considered to be the most beneficial group in the current literature. When the age is higher than 35 years old, due to the accelerated decline of the ovarian function, the number of eggs that can be stored each time will begin to decline, from more than 10 mature eggs to an average of 2-6 eggs. At this moment can start to consider the timing for chemotherapy. If there are 3-4 weeks of spare time, we can plan a second egg retrieval in the same period to increase the number of available mature eggs and improve the subsequent live birth rate.
- Instead of waiting for menstruation, we can start the treatment randomly combined with a pituitary antagonist to reduce the number of days of treatment.
- Aromatase Inhibitor (such as Letrozole mentioned above) or Selective estrogen receptor modulators (such as Tamoxifen) directly reduce breast stimulation (later found that Letrozole is more effective)
- Replace traditional trigger injection with Gonadotropin-releasing hormone agonist to accelerate the shrinkage of the corpus luteum after ovulation.
In the current study, the number of eggs or embryos obtained by the above method is statistically no different from the traditional method. In terms of safety, a systematic review in 2017, including 464 breast cancer patients, showed that receiving ovarian stimulation did not increase the subsequent breast cancer recurrence rate; and according to a 2020 Swedish statistical data, there is no significant difference between 380 patients who had received ovarian stimulation for breast cancer and those who don't receive ovarian stimulation on the five-year statistical survival rate. The current literature evidence supports the safety of ovarian stimulation for breast cancer patients.
In conclusion, the prognosis of breast cancer has been greatly improved with the progress of related treatments; after the diagnosis of breast cancer, the complete treatment plan should not only consider the issue of survival but also consider the follow-up quality of life and social family relationships. For young patients who still want to have babies, it is time to sit down with oncologists and reproductive physicians to discuss the impact of subsequent treatment on fertility, as well as the benefits and safety of egg or embryo freezing, and decide how to plan their future careers better.
