Harmonization and EQA programs for PD-L1 in France
Marie-Pierre Chenard, Strasbourg on the behalf of AFAQAP
6th meeting on external quality assessment in molecular pathology Naples, May 12-13, 2017
Story of PD-L1 in France
• First meeting about PD-L1 testing in Paris, in September 2015, at the initiative of INCa (National Cancer Institute) ; 40 thoracic pathologists working in French university hospitals
• The situation in France :
– Dako or Ventana platforms are not available in all pathology labs (and almost never both of them) ; many labs use a Leica/Bond platform
– PD-L1 assays used in clinical tests are expensive – Reimbursement for this testing is insufficient
Decision of INCa to support projects aimed at evaluating the quality of Laboratory Developed Tests (LDTs) for PD-L1 testing
The projects
1) Explore PD-L1 project of AFAQAP
To evaluate PD-L1 on positive control tissue - tonsil and placenta - in routine conditions with different antibodies on different platforms
2) Project of a working group of 7 thoracic pathologists
To compare the analytic performance of 28-8, 22C3 and SP263 PD-L1 assays across various centers
To determine if laboratory developed tests (LDTs) can achieve an analytical performance close to PD-L1 assays, in a set of NSCLC
Objective
To evaluate routine protocols for PDL1 on 2 samples of positive control tissue
Scoring
% of stained cells : + / ++ / +++
Staining intensity : + / ++ / +++
Tonsil
- Germinal center macrophages : weak to moderate membranous staining reaction
- Epithelial crypt cells : moderate to strong membranous staining reaction
Placenta
Trophoblast /syncytiotrophoblast : strong staining Centralized slide review by two experts (FPL and CB)
Explore PDL1 project
Explore PDL1
Tonsil
Placenta
20 participants - 31 tests
5 CE-IVD/FDA approved assays 26 LDTs
Explore PDL1 project : antibodies used
3
6
14 6
2
0 2 4 6 8 10 12 14 16
22C3 (Dako) 28-8 (5 Abcam, 1 Dako) E1L3N (Cell Signaling) SP142 (4 Ventana, 2 Spring) SP263 (Ventana)
Nb of participants
Antibodies
Explore PDL1 project : results
• Placenta : 30/31 adequate staining reaction of the trophoblastic cells ; only one case with a poor result (with SP142)
• Tonsil : 11/31 insufficient staining reaction of the germinal center cells 5/31 insufficient staining reaction of the epithelial crypt cells
Germinal center macrophages Epithelial crypt cells
Sufficient Poor Sufficient Poor
Explore PDL1 project :
Results according to antibodies, on tonsil
1 2
0 0 0
1 3
4
0 0
1 0
8
0 0
0 1 2
6 2
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
22C3 28-8 E1L3N SP142 SP263
Germinal centre macrophages
% of stained cells
+++
++
+ 0
0 0 0 0 0
0 1 4
0 0
3 3 6
0 0
0
2 4
6 2
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
22C3 28-8 E1L3N SP142 SP263
Epithelial crypt cells
% of stained cells
+++
++
+ 0
Project of the working group
Comment : unfortunately, SP263 will only be available as an assay and restricted to users of Ventana platforms
