Gestational breast cancer refers to breast cancer that occurs during pregnancy and/or lactation, i.e., new breast cancer that occurs within one year of pregnancy or childbirth. In today’s society, women generally marry late and have children later, and the increase of age is related to the occurrence of breast cancer. Moreover, because women during pregnancy and lactation are fully devoted to the conception and growth of children, coupled with the obvious enlargement of breasts, increased blood flow to the breast, obvious swelling and hardening of the breast, and increased density of the breast, breast lumps are easily concealed by the thickened and enlarged glands, making early detection difficult, and even if breast Even if breast lumps are found, it is easy to consider them as hyperplasia or normal physiological phenomenon, which leads to delay in diagnosis and treatment. More importantly, breast cancer is a hormone-responsive tumor, and the level of estrogen and progesterone in the blood circulation increases during pregnancy, which accelerates the growth of tumors and promotes their metastasis. These characteristics make PABC progress rapidly, with a high rate of misdiagnosis, and most of them are already late when they are diagnosed. The success of breast cancer treatment depends largely on the stage of the disease at the time of diagnosis, and the detection of an early stage of breast cancer is far more important to patients than any current treatment options, especially for patients with PABC. Therefore, we call on young women and clinicians to be highly vigilant, to perform meticulous and standardized physical examinations, necessary ultrasound examinations of the breast, targeted puncture and biopsy pathology examinations, and to enhance health education for pregnant women about PABC, so that doctors and patients can work together to improve the early diagnosis rate of PABC. Last but not least, since the attention of both doctors and patients is often focused on the patient’s abdomen and uterus during routine checkups of pregnant women, and there is a lack of sufficient understanding and attention to breast cancer in pregnancy, it is recommended that obstetricians and gynecologists routinely check the breasts and axillae of pregnant women in early pregnancy and continue until breastfeeding. When a lump is found, or when skin thickening, retraction, fixation and suspicious enlarged lymph nodes are detected, further imaging or pathological examination in breast surgery is recommended to improve the early diagnosis of breast cancer in pregnancy. If a diagnosis of breast cancer in pregnancy is made, it is important to visit the breast surgery department, where termination of pregnancy and comprehensive treatment including surgery and chemotherapy can be considered. A recent study published in The Lancet showed that chemotherapy for breast cancer in pregnancy is essentially the same as for non-pregnancy breast cancer and does not significantly increase the risk to mother and baby, although breast cancer in pregnancy is rare (less than 1% of breast cancer cases in Europe), but the incidence of breast cancer in pregnancy is increasing due to the increasing number of older women giving birth. The German Breast Study Group established a breast cancer in pregnancy registry in 2003 and expanded it to include the Netherlands, the United Kingdom, Poland, Italy, and the Czech Republic in 2009. During the same period, a registry incorporating all cases of cancer in pregnancy was also established in Belgium. In this study, Dr. Sibylle and colleagues from this study group evaluated the prognosis of 447 patients in these registries who were diagnosed with early (413) or metastatic (34) breast cancer during pregnancy. The median gestational age at diagnosis was 24 weeks (5-40 weeks) and the median age of the patients was 33 years (22-51 years). Chemotherapy data were obtained for a total of 368 patients, of whom 197 received chemotherapy during pregnancy and 171 after delivery. A total of 1,187 cycles of chemotherapy were administered, 63% of which were administered during pregnancy. Patients received between 1 and 8 (median: 4) cycles of chemotherapy during pregnancy. A total of 90% of patients treated during pregnancy were treated with anthracycline antibiotics; 8% were treated with a combination of cyclophosphamide, methotrexate and fluorouracil; and 7% were treated with paclitaxel. None of the patients received trastuzumab, endocrine therapy or radiotherapy during pregnancy. Patients with early-stage breast cancer who chose to receive chemotherapy during pregnancy tended to have more advanced disease and poorer tumor stage and lymph node status than those who chose to have chemotherapy after delivery. After correcting for differences in these areas, the investigators found no significant differences in disease-free survival or overall survival between the two groups. Patients with early-stage breast cancer who received chemotherapy during pregnancy and chemotherapy after delivery had an estimated 3-year disease-free survival rate of 70.2% vs. 74.3%, an estimated 3-year overall survival rate of 84.9% vs. 87.4%, an estimated 5-year disease-free survival rate of 61.1% vs. 64.4%, and an estimated 5-year overall survival rate of 77% vs. 82.4%. Data were obtained for a total of 373 neonates, 203 of whom were exposed to chemotherapy in utero and 170 of whom were not so exposed. Birth weight of newborns in the gestational exposure group was slightly lower than in the unexposed group, but this difference was not considered clinically significant as it did not affect infant health. In addition, there were no significant differences between the two groups in major birth defects, infant height, Apgar score, hemoglobin concentration, white blood cell count, platelet count, or hair loss. There was also no significant difference in the proportion of infants discharged with their mothers between the two groups (34% vs. 41%). The incidence of adverse events was higher in those who received chemotherapy during pregnancy than in those who received chemotherapy after delivery (15% vs. 4%). However, this difference was due to the higher incidence of preterm delivery and premature rupture of membranes in the group exposed to chemotherapy during pregnancy. Most complications were seen in preterm infants, regardless of the time point of chemotherapy exposure. The data from this study are insufficient to explain the higher rate of preterm birth in mothers who received chemotherapy. However, the reasons may lie in the dual physical and psychological stress, as well as the greater susceptibility of mothers receiving chemotherapy to develop infections that can precipitate labor. In addition, cytotoxic drugs may facilitate labor through some as yet unknown mechanisms. However, the incidence of preeclampsia was similar in both groups, so oxidative stress induced by cytotoxic drugs is not known to be a predisposing factor for preterm delivery. The investigators conclude that these results suggest that the prognosis of pregnancy for those who received chemotherapy for breast cancer in mid- or late-pregnancy is not significantly different from that of mothers who received chemotherapy after delivery, but this result remains to be confirmed by other studies.