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. 2023 Mar 27;69:330–341. doi: 10.1016/j.breast.2023.03.014

Fig. 1.

Fig. 1

Controversies of PD-L1 assessment. A) Graphical representation of different companion diagnostic PD-L1 scores for immune checkpoint treatment of advanced TNBC. The immune cell score (IC, Ventana platform, SP142 anti-PD-L1 clone), accounts for the percent total tumor area occupied by PD-L1 expressing immune cells. The combined positive score (CPS, Dako platform, 22C3 anti-PD-L1 clone), represents the percent ratio of PD-L1 expressing cells (both tumor and immune) on total viable tumor cells. IC does not account for immune cell distribution and PD-L1 expression on tumor cells. CPS lacks information regarding the cell types expressing PD-L1 and their spatial distribution. Both scores may return similar values despite significant biological differences in analyzed samples, as depicted. Graphical legend at the bottom; PD-L1 expression is represented as either red cell membrane or red shadows when considering cell numbers or tumor areas, respectively. B) Conceptual representation of intratumoural poor concordance of different PD-L1 scores. IC and CPS can provide different readouts on the same tumor sample, possibly affecting therapeutic decisions. C) Type, size, and number of tumor tissue sampling can impact PD-L1 detection. The wider the area and the higher the number of samplings, the greater the chances of PD-L1 positivity. Legend: surgical resection, surgeon hand and scalpel; Fine needle agobiopsy, small syringe; Core biopsy, big syringe; sampled areas, red-dotted area, IHC expression of PD-L1, brown areas. D) Comparison between PD-L1 assessment by SP142 (IC ≥ 1%) and 22C3 (CPS≥10) in biomarker-evaluable population of IMpassion130. Overall percentage agreement is 73% (36% both positive; 37% both negative), while 27% of patients display opposite results with the two scores, highlighting the lack of interchangeability. Representative samples of each score combinations are shown on the right. E) Suggested therapeutic algorithm following the considerations from D. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)