Expression of CD28, FAS, PD1, and CTLA4 molecules in the blood of women with triple‐negative breast cancer

Abstract Background Locally advanced triple‐negative breast cancer (TNBC) represents a public health problem in Brazil. Its standard treatment consists of neoadjuvant chemotherapy (NAC). Methods This was a longitudinal study with follow‐up performed between the years 2015 and 2017. Thirty women with locally advanced TNBC submitted to NAC, and 30 healthy were included. Peripheral blood samples were collected before NAC (Pre‐NAC) and after NAC (Post‐NAC). Results Patients with TNBC had elevated levels of CD28+ T, FAS+ T, CTLA4+ T, PD1+ T, CD28+CD4+ T, PD1+CD4+ T and CD8+ T and PD1+ CD8+ T cells compared to controls ( p < 0.05). Patients with pathological complete response (pCR) had low FAS+ T cells, FAS+CD4+ T cells, and PD1+CD8+ T cells compared to the non‐pCR ( p < 0.05). Significant differences were observed in the levels of CD28+ T cells, FAS+ T and PD1+ T, CD4+ T, CD28+CD4+ T, FAS+CD4+ T, PD1+CD4+ T, CD8+ T, and PD1+CD8+ T cells between Pre‐NAC and Post‐NAC groups ( p < 0.05). Conclusion Alterations in the circulating FAS+CD4+ T and PD1+CD8+ T cell levels Pre‐NAC are associated with pCR, suggesting potential predictive biomarkers of NAC response in TNBC. The largest changes in the cellular immune response profile Post‐NAC showed that chemotherapy treatment can modulate the immune response and that it is associated with prognosis in TNBC.