Objective  To observe the clinical efficacy of adjuvant chemotherapy for Luminal A early breast cancer based on the Surveillance, Epidemiology and End Results (SEER) Database of National Cancer Institute(NCI).

  Methods  Using the SEER database, 207 404 cases of Luminal A type breast cancer who had received surgeries at early stage were screened out, and they were divided into chemotherapy group and non-chemotherapy group according to whether applying adjuvant chemotherapy or not, and subtype classification was performed according to clinicopathological characteristics. The cumulative risk curve and survival time of the two groups were compared.

  Results  Luminal A type early breast cancer patients had good overall prognosis, and it was found that the patient's gender, age, race, pathological type, and pathological grade had limited influence on the chemotherapy decision-making of Luminal A type early breast cancer. However, clinical grade and lymph node metastasis N staging had important impacts for chemotherapy decisions.

  Conclusion  In clinical work, the N₁mi staging of lymph node metastasis can be considered as a clinical reference index for patients with Luminal A early breast cancer to avoid adjuvant chemotherapy in the absence of polygenic test results.