Transcriptional profiling of single tumour cells from pleural effusions reveals heterogeneity of epithelial to mesenchymal transition and extra‐cellular matrix marker expression

TABLE 1 Clinical characteristics for nine patients from whom 11 PE samples were obtained Patient Histology Sex Race Age at diagnosis (years) Weeks on therapy at time of PE Driver mutations Therapy at time of PE Smoking Status UPENN-1 Adenocarcinoma F White 56 4 EGFR ex19 del Chemo+ Avastin Former UPENN-2 Adenocarcinoma F Asian 70 19 EGFR L858R TKI + Avastin Never UPENN-3A Adenocarcinoma F White 64 1 BRAF V600E Chemo Former UPENN-3B Adenocarcinoma F White 64 1 BRAF V600E IO Former UPENN-4 Adenocarcinoma F White 53 11 EGFR ex19 del TKI + Avastin Never UPENN-5A Adenocarcinoma F White 78 9 None detected IO Current UPENN-5B Adenocarcinoma F White 78 17 None detected IO Current UPENN-6 Adenocarcinoma M White 74 2 KRAS G12C IO Former UPENN-7 Adenocarcinoma F White 64 12 EGFR Exon 18 p.E709_T710delinsA TKI Never UPENN-8 Adenocarcinoma F White 55 36 EGFR ex19 del TKI + Avastin + Chemo Former UPENN-9 Adenocarcinoma F White 55 3 EGFR L858R TKI Former Abbreviations: IO, immunotherapy; TKI, tyrosine kinase inhibitor. Eight of nine samples had high heterogeneity (ICC score range 0.012–0.261) and one sample (UPENN-7) had low heterogeneity (ICC score 0.663) (Table S10). [...]considerable single-cell heterogeneity exists within patients. The unbiased analysis of TCs allowed the identification of transcriptional differences in EPCAM-positive and EPCAM-negative TCs and uncovered significant intra-patient heterogeneity in gene expression and EMT score.