Breast cancer in young people is more common in China In China, the incidence of breast cancer has been increasing year by year and has become an important factor threatening women’s health. In Beijing, for example, the incidence of breast cancer in urban areas has increased by an average of 4.6% per year in the last 20 years, which is much higher than the global average of 2% per year. Moreover, compared with European and American countries, the peak age of breast cancer incidence in Chinese women has significantly shifted forward. In Europe and the United States, the peak age of incidence is usually between 60 and 70 years old, while the peak age of incidence for Chinese women is between 40 and 50 years old. A national multicenter study spanning 10 years (1999-2008) showed that 38.6% of breast cancers occurred between 40 and 50 years of age, while 18.8% of young breast cancers were under 40 years of age. An analysis of the age composition of a total of 6,838 women with breast cancer in the last 30 years at our hospital yielded similar findings, with a peak age of incidence of 32% between 40 and 50 years of age, compared to 15% of women under 40 years of age. One of the important elements in the diagnosis and management of young breast cancer compared to other age groups is the issue related to fertility. This topic can be addressed in two ways, namely the impact of fertility on the risk of breast cancer recurrence and metastasis, and the impact of breast cancer-related treatment on fertility. Whether childbirth increases the risk of breast cancer recurrence and metastasis, most of the current studies suggest that the answer is no, i.e., childbirth does not increase the risk of breast cancer recurrence and, on the contrary, some studies suggest that childbirth has the effect of reducing breast cancer mortality. A 2013 study published in the American Journal of Clinical Oncology also confirmed the safety of childbearing in breast cancer. This study compared 333 women who gave birth after a breast cancer diagnosis with 874 matched breast cancer patients who did not give birth, and the disease-free survival (recurrence, metastasis and death) was lower in the fertility group than in the control group, but did not reach a significant (p=0.14) difference. Subgroup analysis of hormone receptor status also did not find significant differences. However, fertility resulted in a 28% reduction in mortality in breast cancer patients and benefited both hormone receptor negative and positive patients. Although there is a lack of prospective large-scale studies, the available evidence suggests that at least fertility is safe for the risk of breast cancer recurrence and even has the effect of reducing breast cancer-related mortality. Treatment of breast cancer Fetal risk remains controversial Breast cancer-related treatments can have an impact on fertility, such as chemotherapy for breast cancer. Chemotherapy drugs for breast cancer, especially the alkylating agent cyclophosphamide, have a significant impact on ovarian function and have a clear teratogenic effect. Therefore, cyclophosphamide should be avoided as much as possible for women with fertility requirements. There is some controversy regarding the safety of fetuses born after breast cancer treatment. A Danish study comparing 216 patients with breast cancer and 10,453 without breast cancer showed no significant differences in preterm birth rates, birth weight, complications, or congenital malformations, whereas a Swiss study comparing 331 patients with breast cancer and 287,0932 controls found increased birth complications, an increased proportion of low birth weight infants, and an The study found an increase in birth complications, an increase in low birth weight, and an increase in fetal congenital malformations (7 percent vs. 4 percent). However, a summary of several studies presented at this year’s 50th Annual Meeting of the American Society of Clinical Oncology (ASCO 2014) concluded that the rate of congenital malformations in births to breast cancer patients was 2 to 3 percent and did not increase the risk of birth defects compared to the rest of the population. Preservation of fertility Popular research topics Fertility is very important for women and can even affect family harmony. For fertility preservation in breast cancer patients, in vitro fertilization with embryo freezing is currently considered the most effective. In vitro culture of oocytes after maturation for freezing and direct freezing of follicles or parts of ovarian tissue can also be considered. Since chemotherapy has the greatest impact on fertility, a number of studies have explored ways to protect the ovaries and avoid damage from chemotherapy drugs, with LHRH (luteinizing hormone-releasing hormone) analogs receiving the most attention. The results of Preserving Fertility with Goserelin + Standard Chemotherapy for Breast Cancer (S0230/POEMS study), a phase III prospective randomized controlled study with 257 patients enrolled: 131 (120 eligible) in the standard chemotherapy group and 126 (113 eligible) in the chemotherapy + goserelin group, were presented at ASCO 2014. The two-year rate of premature ovarian failure was 22% in the standard chemotherapy group and 8% in the chemotherapy + goserelin group; there were 13 pregnancies in the standard chemotherapy group and 22 in the chemotherapy + goserelin group. Moreover, the chemotherapy + goserelin group also outperformed the standard chemotherapy group in terms of disease-free survival and overall survival. In conclusion, the preservation of reproductive function is an issue that needs to be given attention during the treatment of breast cancer, especially young breast cancer. As far as the available evidence is concerned, fertility has no effect on the risk of breast recurrence and even has the effect of reducing mortality; while the treatment of breast cancer, especially chemotherapy, has an impact on the reproductive function of breast cancer patients. When choosing drugs, try to avoid drugs that are highly damaging to the ovaries, while LHRH analogues can be considered to protect ovarian function.