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János Fillinger
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P2.04 - Immunooncology (Not CME Accredited Session) (ID 953)
- Event: WCLC 2018
- Type: Poster Viewing in the Exhibit Hall
- Track:
- Presentations: 1
- Moderators:
- Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall
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P2.04-08 - Platinum-Based Chemotherapy is Associated with Altered PD-L1 Expression in Lung Cancer (ID 13755)
16:45 - 18:00 | Author(s): János Fillinger
- Abstract
Background
While the predictive value of programmed cell death ligand-1 (PD-L1) protein expression for immune checkpoint inhibitor therapy of lung cancer has been extensively studied, the impact of standard platinum-based chemotherapy on PD-L1 or programmed cell death-1 (PD-1) expression is unknown. The aim of this study was to determine the changes in PD-L1 expression of tumor cells (TC) and immune cells (IC), in PD-1 expression of IC, and in the amount of stromal mononuclear cell infiltration after platinum-based chemotherapy in patients with lung cancer.
a9ded1e5ce5d75814730bb4caaf49419 Method
We determined the amount of stromal mononuclear cells and PD-L1/PD-1 expressions by immunohistochemistry in bronchoscopic biopsy samples including 20 adenocarcinomas (ADC), 15 squamous cell carcinomas (SCC), 2 other types of non-small cell lung cancer (NSCLC), and 4 small cell lung cancers (SCLC) together with their corresponding surgical resection tissues after platinum-based chemotherapy.
4c3880bb027f159e801041b1021e88e8 Result
PD-L1 expression of TC decreased in 10 patients (24.4%) and increased in 3 patients (7.32%) after neoadjuvant chemotherapy (p=0.051). The decrease in PD-L1 expression, however, was significant only in patients who received cisplatin-gemcitabine combination (p=0.020), while in the carboplatin-paclitaxel group no similar tendency could be observed (p=0.432). There was no difference between ADC and SCC groups. Neither PD-1 expression nor the amount of stromal IC infiltration showed significant changes after chemotherapy.
8eea62084ca7e541d918e823422bd82e Conclusion
This is the first study, in which both PD-L1 and PD-1 expression were analyzed together with the amount of stromal IC infiltration in different histological subtypes of lung cancer before and after platinum-based chemotherapy. Our results confirm that chemotherapy decreases PD-L1 expression of TC in a subset of patients, therefore rebiopsy and re-evaluation of PD-L1 expression may be necessary for the indication of immune checkpoint inhibitor therapy.
6f8b794f3246b0c1e1780bb4d4d5dc53
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P3.12 - Small Cell Lung Cancer/NET (Not CME Accredited Session) (ID 978)
- Event: WCLC 2018
- Type: Poster Viewing in the Exhibit Hall
- Track:
- Presentations: 1
- Moderators:
- Coordinates: 9/26/2018, 12:00 - 13:30, Exhibit Hall
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P3.12-13 - Expression of the Immune Checkpoint Axis-PVR/TIGIT in Small Cell Lung Cancer (ID 13994)
12:00 - 13:30 | Author(s): János Fillinger
- Abstract
Background
The poliovirus receptor (PVR) is an immune checkpoint protein expressed on tumor cells. It has been reported to mediate activation of T cells via CD226 or inhibition through binding to T-cell Ig and ITIM domain (TIGIT). TIGIT competes with CD226 for binding to PVR, and exhibits stronger affinity for PVR. Recently we have found that PVR is highly expressed in SCLC cell lines. Characterizing the expression and significance of the PVR-TIGIT axis in SCLC will help us to better understand the immunology of SCLC and may lead to novel therapeutic strategies to combine checkpoint blocking agents for improved SCLC immunotherapy.
a9ded1e5ce5d75814730bb4caaf49419 Method
Immunohistochemistry (IHC) was performed to evaluate PVR protein expression in a TMA of 39 SCLC cell lines and a cohort TMA of 77 limited stage SCLC patients with clinical data. We analyzed both PVR and TIGIT in an independent cohort of 27 resected, limited-stage SCLC tumors.
4c3880bb027f159e801041b1021e88e8 Result
Thirty-seven cell lines (95%, 37/39) demonstrated staining for PVR and of those, 4 cell lines (10.3%, 4/39) showed strong staining (H-score ≥ 270). In the 77 SCLC patients cohort, PVR expressed predominantly in the membrane of tumor cells, with minimal expression observed on immune cells. PVR expression in the SCLC patient cohort was 82% with an arbitrary H-score cut-off of ≥ 50. Higher PVR expression was found for male patients (P=0.040). The expression of PVR increased with the tumor progressing from stage I to stage III (p =0.007). SCLC patients who had higher PVR expression demonstrated poorer prognosis and the difference was near statistically significant (p=0.050). Using the same cut-off (H-score ≥ 50) in the independent SCLC cohort, the prevalence of high PVR expression was 89% (24/27).
In the independent SCLC cohort, TIGIT was found to be expressed membranous or cytoplasm on the immune cells with weak to moderate staining. Immune cells with TIGIT staining were typically seen as variable size and aggregated toward the periphery of the tumor nest. TIGIT protein staining was demonstrated in 20 cases (74%). No association was found between PVR H-score and TIGIT expression by Fisher’s test (p=0.093).
8eea62084ca7e541d918e823422bd82e Conclusion
PVR is broadly expressed in SCLC cell lines and tumor tissues. The expression of TIGIT protein was also found in SCLC patients with weak to moderate staining. Blockade of the PVR-TIGIT pathway may represent a possible future target to immunotherapy in SCLC patients.
6f8b794f3246b0c1e1780bb4d4d5dc53
