179P - Integrating multiplex immunofluorescence with gene expression data in the IMMUcan HER2-positive breast cancer cohort

Background

IMMUcan (SPECTA NCT02834884) is an ongoing European effort to profile the tumor microenvironment (TME) in different cancer types. HER2-positive breast cancer (HER2+ BC) is heterogeneous, and TME characteristics impact treatment response. Here, we explored the correlation between multiplex immunofluorescence (mIF) and gene expression data in the IMMUcan prospective neoadjuvant early-stage HER2+ BC cohort.

Methods

A cohort of 149 patients was identified for preliminary analyses. mIF data were obtained from pretreatment tumor biopsies using 3 panels of marker antibodies [cytokeratin, CD15, CD163, CD11c, CD20, CD3, PD1, PD-L1, Ki67, granzyme B (GB), CD8, CD4, CD56, FOXP3] in 49 patients, evaluating stroma and tumor regions. Paired RNA sequencing (RNAseq) data were available for 44/49 patients. Spearman correlations (significant for P <0.05) were computed between mIF marker/cell phenotype densities (cells/mm²) and selected genes/gene expression signatures (GESs).

Results

Correlations between immune GESs and mIF markers/phenotypes ranged between 0.3 and 0.71. Of note, the gene CD274 and PD-L1 mIF stromal density presented high correlation (0.7), while the B cell stromal density correlated with a tertiary lymphoid structure GES (0.6). GESs describing proliferation were correlated with the densities of Ki67+ tumor cells (0.57 to 0.66), as well as with PD-L1 and several cell types (e.g., PD1+/Ki67+ tumor cells, CD8+/GB+/PD-L1+ cells, CD163-expressing macrophages; range 0.3 to 0.58). Expression levels of a PTEN loss GES was positively correlated with PD-L1 densities in both tumor and stroma (0.66 to 0.67), while GESs depicting glucose and lipid metabolism correlated (0.31 to 0.48) with CD163-expressing macrophages densities. Finally, negative correlations were observed between stroma-related signatures and densities of immune cells/markers (particularly CD8+ cells) as well as of proliferative tumor cells (-0.3 to -0.62).

Conclusions

In these preliminary analyses in the IMMUcan study, correlations between mIF and RNAseq data unveil biological processes potentially responsible for different immune infiltration patterns in HER2+ BC. Additional analyses are ongoing and further validation is warranted.

Clinical trial identification

NCT02834884; First posted: July 15, 2016.

Legal entity responsible for the study

EORTC.

Funding

IMI2 JU grant agreement 821558, supported by EU’s Horizon 2020 and EFPIA.

Disclosure

M. Morfouace: Financial Interests, Personal, Full or part-time Employment: Merck KGaA. L. Greillier: Financial Interests, Personal, Advisory Board: AbbVie, AstraZeneca, BMS, MSD, Novartis, Sanofi, Takeda, Roche; Financial Interests, Personal, Invited Speaker: Lilly, Pfizer; Financial Interests, Institutional, Local PI: AstraZeneca, AbbVie, BMS, MSD, Novartis, Takeda, Pfizer, PharmaMar; Financial Interests, Institutional, Coordinating PI: Sanofi; Financial Interests, Personal, Local PI: Roche. H.S. Hong: Financial Interests, Personal, Full or part-time Employment: Merck KGaA. M. Cesaroni: Financial Interests, Personal, Full or part-time Employment: Sanofi. C. Sotiriou: Financial Interests, Institutional, Advisory Board: Astellas, Vertex, Seattle Genetics, Amgen, INC, Merck & Co; Financial Interests, Personal, Advisory Board: Cepheid, Puma; Financial Interests, Personal, Invited Speaker: Eisai, Prime oncology, Teva; Financial Interests, Institutional, Other, Travel: Roche; Financial Interests, Institutional, Other, Internal speaker: Genentech; Financial Interests, Personal, Other, Regional speaker: Pfizer; Financial Interests, Institutional, Invited Speaker: Exact Sciences. L. Buisseret: Financial Interests, Institutional, Advisory Board: Domain Therapeutics; Financial Interests, Institutional, Other, Steering Committee: iTEOS Therapeutics; Financial Interests, Personal, Other, writing of clinical cases: Mirrors of Medicine; Financial Interests, Institutional, Other, Travel grant: Gilead; Financial Interests, Institutional, Research Grant, Research Grant for an investigator initiated trial: AstraZenaca; Non-Financial Interests, Personal, Principal Investigator: iTeos Therapeutics; Non-Financial Interests, Personal, Member: EORTC, BSMO. All other authors have declared no conflicts of interest.