I. How did the results of this study come about? First, let’s understand two concepts: genetic risk and clinical risk. Clinical risk: Clinically, patients with early-stage breast cancer are considered to be at “high clinical risk” if they meet indicators such as age below 50 years and lymph node metastasis. Genetic risk: This test uses 70 genes to classify the “genetic risk” of breast cancer. According to breast cancer clinical guidelines, it is standard for breast cancer patients with high clinical risk to undergo adjuvant chemotherapy after surgery or radiation therapy. Should chemotherapy be administered to all patients with high clinical risk breast cancer? It is important to know that the side effects of chemotherapy can sometimes cause long-lasting damage, such as infertility. In this randomized phase 3 study, researchers recruited 6693 women with early-stage breast cancer and determined their genomic risk and their clinical risk. The study found that: (1) 54% of the “clinical high risk” patients were “genetically high risk”. Therefore, adjuvant chemotherapy in these patients can significantly reduce the risk of recurrence and prolong survival time. (2) Among the patients with “high clinical risk”, 46% of them belonged to “low genetic risk”. Within 5 years, the survival rate of patients who did not receive chemotherapy was 94.7% without distant metastases. The rate of survival without distant metastases was only 1.5 percentage points higher for patients who received chemotherapy than for those who did not receive chemotherapy. The researchers concluded that the above findings imply that it is safe and feasible to forgo postoperative chemotherapy for patients with early-stage breast cancer who are at higher clinical risk and lower genomic risk. That is, approximately 46% of women with breast cancer at high clinical risk of recurrence may not need chemotherapy. Many times in the past, when people talked about breast cancer, the focus of the conversation was how chemotherapy would be administered in addition to surgical removal. With the development of the times and the advancement of genetic testing technology, people are gradually discovering that actually early stage breast cancer patients do not necessarily need chemotherapy. After receiving certain treatment, early stage breast cancer patients can undergo genetic testing to determine whether they are genetically high risk and then decide with their doctors whether they need chemotherapy or not. It is believed that in the near future, more and more early stage breast cancer patients will not be overly treated with chemotherapy and will enjoy the benefits of various research findings.