CD8+ as a Predictive Factor for Response to Anthracycline-Based Neoadjuvant Chemotherapy in Patients with Locally Advanced Breast Cancer at Dr. Soetomo General Hospital, Surabaya, January 2024-August 2025

Abstract

Breast cancer remains a major global health issue. In Indonesia, approximately 70% of breast cancer cases are diagnosed at the locally advanced stage (LABC). Neoajuvant chemotherapy (NAC) is the treatment of choice for LABC, significantly reducing tumor size prior to surgical resection. CD8+ cytotoxic T-cells are a major component of tumor-infiltrating lymphocytes (TILs) and play a key role in inhibiting tumor proliferation. High CD8+ T cell infiltration has been associated with improved NAC response. This study aims to evaluate the potential of CD8+ T cell density as a significant predictor of clinical response to NAC. This retrospective cohort study involved 54 LABC patients who underwent NAC prior to surgical breast resection at Dr. Soetomo General Hospital from January 2024 to August 2025. The association between CD8+ T cell density and clinical response to NAC was analyzed using the Chi-square test or Fisher's exact test, as appropriate. Logistic regression analysis was conducted to determine whether high CD8+ density served as a predictive factor for a positive chemotherapeutic response. Statistical significance was defined as p<0.05. A statistically significant association was found between high CD8+ T cell density and a positive clinical response to NAC (p<0.001; OR 5.19; 95% CI: 1.87–14.42). High CD8+ density was shown to be a significant predictor of a favorable clinical response to neoajuvant chemotherapy (p<0.001). High CD8+ T cell density may serve as an independent and significant predictor of a positive clinical response in LABC patients receiving neoajuvant chemotherapy.