Long-term Effectiveness of Adjuvant TAC and AC Chemotherapy Regimens in Patients with Stage II–IIIA Breast Cancer: 15-Year Follow-up Results from K Hospital, Hanoi

Huong Thu Nguyen; Linh Dieu Nguyen

doi:10.31557/APJCC.2026.11.4.591

Authors

Huong Thu Nguyen Breast Department, Vinmec Times City International Hospital, Viet Nam.
Linh Dieu Nguyen Department of Gynecologic Oncology, National Hospital of Obstetrics and Gynecology, Hanoi, Vietnam.

DOI:

https://doi.org/10.31557/APJCC.2026.11.4.591

Keywords:

Breast cancer; late event, adjuvant chemotherapy; TAC; AC; survival; recurrence

Abstract

Introduction: Adjuvant chemotherapy with TAC or AC regimens is widely used in stage II–IIIA breast cancer, but their long-term comparative effectiveness and late toxicity profiles remain unclear. This study aimed to compare long-term outcomes of TAC versus AC regimens in patients with stage II–IIIA breast cancer, focusing on disease-free survival (DFS), time to recurrence (TTR), overall survival (OS), and late adverse events.

Materials and Methods: In this retrospective-prospective cohort study, 94 patients treated with TAC (n = 31) or AC (n = 63) between 2008 and 2011 were followed prospectively through October 2025. Kaplan–Meier analysis and log-rank tests estimated survival, and Cox proportional hazards models assessed mortality risk. Of the 94 patients, 23 (74%) in the TAC group and 42 (67%) in the AC group completed 15-year follow-up; others were censored for loss to follow-up or competing mortality.

Results: Adverse events varied over time but were similar between regimens. During year 1, hot flashes (32.3% vs. 22.2%) and menstrual disturbances (25.8% vs. 17.5%) were most common, while arthralgia increased during years 1–5 (31.0% vs. 22.4%). Late toxicities after 5 years, including osteoporosis/fractures (21.7% vs. 20.0%) and persistent sexual dysfunction (26.1% vs. 24.4%), were comparable. Over 15 years, DFS events occurred less frequently with TAC (38.7% vs. 58.7%), with lower distant recurrence (32.3% vs. 52.4%, p = 0.043) and longer median TTR (88.5 vs. 71.2 months). TAC was associated with lower recurrence and a trend toward longer median OS (162 vs. 112 months; HR = 0.73, 95% CI: 0.56–0.95, p = 0.018), though log-rank test was not significant (p = 0.163).

Conclusion: TAC was linked to lower recurrence and longer OS without significantly increased adverse events. Observations are exploratory and cannot establish causality; larger prospective studies are needed to confirm these findings.