Effect of Primary Systemic Therapy on PD-1, PD-L1, and PD-L2 mRNA Expression in Advanced Breast Cancer

Immunohistochemical Evaluation of Perlecan (Heparan Sulphate Proteoglycan 2) Expression in Invasive Female Breast Carcinoma

BACKGROUND

Breast cancer (BC) is the commonest type of female cancer worldwide and a leading cause of cancer-related deaths. Perlecan expression increases in aggressive breast cancers, pointing to a possible significance of this novel target therapy. Consequently, the current research investigates the immunohistochemical expression of Perlecan by tumor cells in female breast cancer and the correlation of such expression with the pathologic parameters of the tumors.

METHODS

A retrospective cross-sectional investigation was carried out. Seventy-four formalin-fixed, paraffin-embedded breast carcinoma tissue samples from patients undergoing modified radical mastectomy (MRM) or conservative breast surgery (CBS) were collected from the pathology department at Kasr El Aini Hospital. The paraffin blocks were sectioned and immunostained with Perlecan, and their expression was investigated in tumor cells and evaluated according to the H-score and classified into low and high expression. The expression was statistically correlated with the clinicopathological parameters of the cases.

RESULTS

Perlecan expression was low in 41 cases (55.4%) and high in 33 cases (44.6%). It showed a statistically insignificant correlation with all studied parameters, but increased Perlecan expression was directly associated with poor tumor prognostic factors including higher tumor grade, advanced T stage, N3 stage, advanced anatomic stage, high Ki-67 index, positive lymphovascular invasion and perineural invasion, luminal B molecular subtype, and HER2 over-expression.

CONCLUSION

Perlecan expression measured by immunohistochemical staining is associated with aggressive characteristics in breast cancer, suggesting that Perlecan may help in cancer progression and can be investigated as a possible target therapy.

Programmed death receptor ligand-2 (PD-L2) bearing extracellular vesicles as a new biomarker to identify early triple-negative breast cancer patients at high risk for relapse

PURPOSE

Based on the tumor-promoting features of extracellular vesicles (EV) and PD-L1/2-bearing EV subpopulations (PD-L1/2_EV), we evaluated their potential as surrogate markers for disease progression or eligibility criteria for PD-1 immune checkpoint inhibition (ICI) approaches in early triple-negative breast cancer (TNBC).

METHODS

After enrichment of EV from plasma samples of 56 patients before and 50 after chemotherapy (CT), we determined levels of EV particle number and PD-L1/2_EV by nanoparticle tracking analysis or ELISA and associated the results with clinical status/outcome and the presence of distinct circulating tumor cells (CTC) subpopulations.

RESULTS

Compared to healthy controls, patients had a tenfold higher EV concentration and significantly elevated PD L2_EV but not PD L1_EV levels. The most important clinical implications were found for PD-L2_EV. High PD-L2_EV levels were associated with a significantly reduced 3-year progression-free and overall survival (PFS and OS). A loss of PD-L2_EV after CT was significantly more prominent in patients achieving pathological complete response (pCR). Increased pre-CT PD-L2_EV levels were found in patients having NOTCH1-positive or ERBB3-positive CTC. The presence of ERBB3-positive CTC combined with high pre-CT PD-L2_EV resulted in a shorter PFS.

CONCLUSION

This study highlights PD L2_EV as a promising biomarker for risk assessment of TNBC patients and represents the basic for additional studies introducing PD-L2_EV as an eligibility criterion for PD-1 ICI approaches.