Objective: To analyze the influence of epirubicin cyclophosphamide taxane (AC-T) sequential chemotherapy regimen on serum tumor markers levels and prognosis in patients with breast cancer. Methods: A total of 82 patients with breast cancer admitted to the hospital from May 2020 to February 2023 were selected and divided into AC-T synchronous group (AC-T synchronous treatment) and AC-T sequential group (AC-T sequential chemotherapy) according to different treatment methods. The data of 82 patients with breast cancer were analyzed by propensity score matching. After balancing the potential confounding factors such as age, tumor staging, menopause situation and molecular typing, there were 39 pairs of patients with no statistically significant differences in baseline. After treatment, the levels of tumor markers [carbohydrate antigen (CA153), carcinoembryonic antigen (CEA)], score of quality of life [quality of life questionnaire-breast cancer 23 (QLQ-BR23)], safety and prognosis were compared between the two groups. Results: After treatment, the levels of CA153 and CEA in the two groups were lower than those before treatment, and the levels in AC-T sequential group were lower than those in AC-T synchronous group (P<0.05). After treatment, the QLQ-BR23 score in the two groups was lower than that before treatment, and the score was lower in AC-T sequential group than that in AC-T synchronous group (P<0.05). There were no statistical differences in the incidence rates of adverse reactions such as peripheral neuropathy, gastrointestinal reaction, alopecia and abnormal liver function between the two groups (P>0.05). However, the incidence rates of adverse reactions such as neutropenia, anemia and cardiotoxicity in AC-T sequential group were lower than those in AC-T synchronous group (P<0.05). After follow-up until September 2025, there was no statistical significance in the median time of recurrence between AC-T sequential group (20 months) and AC-T synchronous group (15 months) (Log-Rank χ2=3.489, P=0.062). Conclusion: AC-T sequential chemotherapy regimen can reduce the levels of serum tumor markers and improve the quality of life in patients with breast cancer, with certain safety.