Immunoscore CD3/CD8 and FOXP3 Expression Correlate to Neoadjuvant Chemotherapy Response in Triple Negative Breast Cancer: A Case-Control Study.

OBJECTIVES

To explore the significance of diminished CD3/CD8 and CD3/CDR45RO immunoscores, as well as elevated FOXP3 expression, as potential risk factors for unfavorable responses to neoadjuvant chemotherapy among patients with triple-negative breast cancer (TNBC).

METHODS

A case-control study was conducted across two hospitals (a public and a private facility) from August 1st, 2021, to August 31st, 2022. The study population comprised patients diagnosed with the TNBC subtype, with available paraffin blocks from biopsy procedures. Immunohistochemical staining was performed on specimens for CD3, CD8, CD45RO, and FOXP3 antibodies.

RESULTS

A total of seventy-two patients were enrolled in the study, among whom seven patients (16.7%) achieved a pathological complete response to neoadjuvant chemotherapy (NAC). Notably, there existed a significant correlation between CD3/CD8 and CD3/CD45RO immunoscores, as well as FOXP3 expression, and NAC response (p<0.05). Multivariate analysis involving 70 samples from the case-control study revealed that a diminished CD3/CD8 immunoscore (aOR=10.930; 95% CI=1.336-89.420) and heightened FOXP3 expression (aOR=11.775; 95% CI =2.537-54.656) independently posed as risk factors for unfavorable NAC response (p<0.05). However, the CD3/CD45RO immunoscore did not emerge as an independent risk factor for NAC response.

CONCLUSIONS

A reduced CD3/CD8 immunoscore and elevated FOXP3 expression stand as autonomous risk factors for suboptimal NAC response in patients with TNBC.