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Updated: Aug 16, 2026
Multiplexed Immunofluorescence Analysis and Quantification of Intratumoral PD-1+ Tim-3+ CD8+ T Cells
Published on: February 8, 2018
PD-L1 (CD274) copy number gain, expression, and immune cell infiltration as candidate predictors for response to
Jan Budczies1, Gunhild Mechtersheimer2, Carsten Denkert1
1Institute of Pathology, Charité University Hospital, Berlin, Germany; German Cancer Consortium (DKTK), partner sites Heidelberg and Berlin, and German Cancer Research Center (DKFZ), Heidelberg, Germany.
Abstract:
Soft-tissue sarcomas (STS) are rare malignancies that account for 1% of adult cancers and comprise more than 50 entities. Current therapeutic options for advanced-stage STS are limited. Immune checkpoint inhibitors targeting the PD-1/PD-L1 signaling axis are being explored as new treatment modality in STS; however, the determinants of response to these agents are largely unknown. Using the sarcoma data set of The Cancer Genome Altas (TCGA) and an independent cohort of untreated high-grade STS, we analyzed DNA copy number status and mRNA expression of PD-L1 in a total of 335 STS cases. Copy number gains (CNG) were detected in 54 TCGA cases (21.1%), of which 21 (8.2%) harbored focal PD-L1 CNG and that were most prevalent in myxofibrosarcoma (35%) and undifferentiated pleomorphic sarcoma (34%). In the untreated high-grade STS cohort, we detected CNG in six cases (7.6%). Analysis of co-amplified genes identified a 5.6-Mb core region comprising 27 genes, including JAK2. Patients with PD-L1 CNG had higher PD-L1 expression compared with STS without CNG (fold change, 1.8; p = 0.02), an effect that was most pronounced in the setting of focal PD-L1 CNG (fold change, 3.0; p = 0.0027). STS with PD-L1 CNG showed a significantly higher mutational load compared with tumors with a diploid PD-L1 locus (median number of mutated genes; 58 vs. 40; p = 3.6E-06), and PD-L1 CNG were associated with inferior survival (HR = 1.82; p = 0.025). In contrast, T-cell infiltrates quantified by mRNA expression of CD3Z were associated with improved survival (HR = 0.88; p = 0.024) and consequently influenced the prognostic power of PD-L1 CNG, with low CD3Z levels conferring poor survival in cases with PD-L1 CNG (HR = 1.8; p = 0.049). These data demonstrate that PD-L1 GNG and elevated expression of PD-L1 occur in a substantial proportion of STS, have prognostic impact that is modulated by T-cell infiltrates, and thus warrant investigation as response predictors for immune checkpoint inhibition.
Insights
Copy number gains in PD-L1 occur in soft-tissue sarcomas (STS), correlating with higher PD-L1 expression and poorer survival. T-cell infiltrates modify this prognosis, suggesting PD-L1 copy number gains and T-cell levels predict response to immune checkpoint inhibitors in STS.
Area of Science:
- Oncology
- Genetics
- Immunology
Background:
- Soft-tissue sarcomas (STS) are rare cancers with limited treatment options for advanced stages.
- Immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 are a potential new therapy, but response predictors are unknown.
Purpose of the Study:
- To investigate the role of PD-L1 copy number gains (CNG) and expression in STS.
- To determine if PD-L1 CNG and T-cell infiltrates impact survival and predict ICI response.
Main Methods:
- Analyzed DNA copy number and mRNA expression of PD-L1 in 335 STS cases from TCGA and an independent cohort.
- Assessed co-amplified genes, PD-L1 expression levels, tumor mutational load, and T-cell infiltrates (CD3Z mRNA).
Main Results:
- PD-L1 CNG detected in 21.1% of TCGA cases and 7.6% of the independent cohort, prevalent in myxofibrosarcoma and undifferentiated pleomorphic sarcoma.
- PD-L1 CNG correlated with higher PD-L1 expression (fold change 1.8-3.0) and increased mutational load (58 vs. 40 mutated genes).
- PD-L1 CNG was associated with inferior survival (HR=1.82), while T-cell infiltrates (CD3Z) predicted improved survival (HR=0.88). Low CD3Z levels conferred poor survival in PD-L1 CNG cases.
Conclusions:
- PD-L1 copy number gains and elevated PD-L1 expression are present in a significant proportion of STS.
- PD-L1 CNG has prognostic impact, modulated by T-cell infiltrates, suggesting its utility as a response predictor for ICIs in STS.
