Radiotherapy-free neoadjuvant strategy using sintilimab plus XELOX in locally advanced rectal cancer: A single-arm phase II trial

Figure 4 Multiplex immunofluorescence analysis of the tumor immune microenvironment and immune cell infiltration in patients receiving neoadjuvant sintilimab plus chemoradiotherapy. A-D: Representative multiplex immunofluorescence images of the tumor immune microenvironment at 20 × or 80 × magnification. Image showing the same pathological complete response rate (pCR) patient (A and C); Image showing the same non-pCR patient (B and D). The yellow boxed regions in the 20 × images (upper left) are further magnified at 80 × (lower right). A and B demonstrate programmed cell death protein 1 and CD8 co-localization in CD8+ T cells, while panels C and D demonstrate CD163 and CD8 co-localization in M2 macrophages; E-J: Immune cell infiltration levels in the tumor tissue after neoadjuvant sintilimab and chemoradiotherapy between patients achieving pCR (n = 4) and non-pCR (n = 7) assessed by multiplex immunofluorescence. PD-1: Programmed cell death protein 1; PD-L1: Programmed death ligand 1; pCR: Pathological complete response rate.