Predictive Value of Immune Activity Changes in Breast Cancer Patients Treated With Dose-dense Neoadjuvant Chemotherapy: A Retrospective Study.

Background/aim: Dose-dense chemotherapy is recommended for patients with breast cancer who have a high recurrence risk. However, whether dose-dense neoadjuvant chemotherapy (ddNAC) improves patient prognoses compared to the normal-dose regimen remains controversial. In this study, we evaluated the predictive value of immune activities on short-term outcomes for patients treated with ddNAC.

Patients and methods: We classified 82 patients with human epidermal growth factor receptor 2-negative breast cancer treated with NAC into a normal dose group (62 patients) and ddNAC group (20 patients) and examined the differences in clinicopathological features. The ddNAC group was further divided according to patient responses to NAC and the predictive factors for pathological complete response (pCR) were evaluated.

Results: There were no differences in the clinicopathological features before NAC between the normal dose and ddNAC groups. Although the pCR rates tended to be higher in the ddNAC group compared than those in the normal dose group (35.0% vs. 25.8%), there was not significant difference (p=0.264). Among all patients treated with ddNAC, the absolute lymphocyte count decreased and the neutrophil-to-lymphocyte ratio increased during dose-dense doxorubicin plus cyclophosphamide treatment. There was no significant correlation between the pCR and any of the clinicopathological parameters tested including systemic peripheral markers and tumor-infiltrating lymphocyte levels.

Conclusion: ddNAC affected the levels of systemic peripheral immune markers. However, monitoring these markers may not be useful for predicting responses to ddNAC.