Comparative Efficacy of Adjuvant Chemotherapy Regimens for Breast Cancer: A Study on Cyclophosphamide and Doxorubicin (AC) Versus Paclitaxel (T) and the Impact of Biological Characteristics

Background: Cyclophosphamide plus doxorubicin (AC) and single-agent paclitaxel (T) have been shown to be major and effective adjuvant chemotherapy regimens for breast cancer. Personalized treatment plans tailored to individual patient factors have demonstrated significant improvements in curative performance. This study investigated the dataset provided by the CALGB 40101 trial, a phase III randomized study that compared the efficacy of AC and T as adjuvant therapy for breast cancer. Methods: The overall survival (OS) and disease-free survival (DFS) distributions grouped by several factors were described by the Kaplan-Meier method. Additionally, the impact of various factors on the OS and DFS was observed by the Cox proportional hazard model. By stratifying data into different subgroups, the model also showed the association between the characteristics and the efficacy of different regimens. Results: A significant impact of the agents on OS was observed and the HR was 1.279, while different treatment durations did not show a significant association with OS. Also, the agent significantly affected DFS, while a significant difference grouped by duration was not observed. Furthermore, factors, such as tumor size and age, significantly increased the hazard of mortality and relapse. Conclusion: The efficacy of AC and T had significant differences when treating breast cancer as adjuvant therapy, while the treatment duration did not show a significant impact. Also, age, tumor size, receptor status, and histologic grade significantly affect overall or disease-free survival.