Abstract 6213: Determination of permissive and restraining cancer-associated fibroblast (DeCAF) subtypes

Abstract

Abstract Cancer-associated fibroblasts (CAFs) in pancreatic adenocarcinoma (PDAC) are known to play a significant role in regulating tumor progression, invasion, and metastasis. Multiple studies using experimental strategies, as well as single-cell RNA-sequencing (scRNAseq) technology, have shown the existence of subpopulations of PDAC CAFs, with divergent physical and biological characteristics. However, how these CAF subpopulations translate to clinical practice remains unclear. Using a combination of sc- and bulk RNAseq data, we present two CAF subtypes with permissive (permCAF) and restraining (restCAF) characteristics in patients, and developed a clinically usable single-sample classifier (DeCAF) using using 11 independent datasets with high reproducibility (AUC = 0.961). We found that the permCAF patients tend to be associated with a “myxoid” histological features, while restCAF samples were more “collagenized” (p = 0.018). Patients with permCAF tumors had a median overall survival (OS) of 18.5 m compared to 30.2 m for restCAF tumors, with a stratified HR = 1.66 (p < 0.001) for patients with permCAF tumors. Basal-like tumors were found to be associated permCAF subtype (p < 0.001). DeCAF and PurIST (basal-like/classical) subtypes were independently associated with OS (p < 0.001). Analysis of a phase Ib trial FOLFIRINOX in combination with a CCR2 inhibitor (PF-04136309; NCT01413022) , we found that in patients with classical tumors, increasing permCAF probability was associated with response (r = -0.688, p<0.001). Tumors with permCAF subtype are enriched in neutrophils using CIBERSORT and may explain the positive response to CCR2 inhibition. More intriguingly, we found similar associations with OS in kidney renal clear cell carcinoma (KIRC, p = 0.001) and mesothelioma (MESO, p = 0.019). DeCAF subtypes are associated with histological subtype in MESO (p = 0.021) and grade in KIRC (p = 0.056). Taken together, DeCAF subtypes explain the role of CAF subtypes in patients, provide a foundation for the translation of preclinical studies, and facilitate the design of future therapeutic approaches and clinical trials. Citation Format: Xianlu Laura Peng, Elena Kharitonova, Joseph Kearney, Yi Xu, Priscilla Chan, Changfei Luan, Brian Belt, Roheena Panni, Arthi Hariharan, Ian McCabe, Ashley Morrison, Ashley Cliff, David C. Linehan, Alina Iuga, Naim U. Rashid, Jen Jen Yeh. Determination of permissive and restraining cancer-associated fibroblast (DeCAF) subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6213.