Ultra-sensitive CTC-based liquid biopsy for pancreatic cancer enabled by large blood volume analysis

Abstract

The limited sensitivity of circulating tumor cell (CTC) detection in pancreatic adenocarcinoma (PDAC) stems from their extremely low concentration in the whole circulating blood, necessitating enhanced detection methodologies. This study sought to amplify assay-sensitivity by employing diagnostic leukapheresis (DLA) to screen large blood volumes. Sixty patients were subjected to DLA, with a median processed blood volume of ~ 2.8 L and approximately 5% of the resulting DLA-product analyzed using CellSearch (CS). Notably, DLA significantly increased CS-CTC detection to 44% in M0-patients and 74% in M1-patients, yielding a 60-fold increase in CS-CTC enumeration. DLA also provided sufficient CS-CTCs for genomic profiling, thereby delivering additional genomic information compared to tissue biopsy samples. DLA CS-CTCs exhibited a pronounced negative prognostic impact on overall survival (OS), evidenced by a reduction in OS from 28.6 to 8.5 months (univariate: p = 0.002; multivariable: p = 0.043). Additionally, a marked enhancement in sensitivity was achieved (by around 3-4-times) compared to peripheral blood (PB) samples, with positive predictive values for OS being preserved at around 90%. Prognostic relevance of CS-CTCs in PDAC was further validated in PB-samples from 228 PDAC patients, consolidating the established association between CTC-presence and reduced OS (8.5 vs. 19.0 months, p < 0.001). In conclusion, DLA-derived CS-CTCs may serve as a viable tool for identifying high-risk PDAC-patients and aiding the optimization of multimodal treatment strategies. Moreover, DLA enables comprehensive diagnostic profiling by providing ample CTC material, reinforcing its utility as a reliable liquid-biopsy approach. This high-volume liquid-biopsy strategy presents a potential pathway for enhancing clinical management in this malignancy.

Diagnostic leukapheresis reveals distinct phenotypes of NSCLC circulating tumor cells

“…Confirming prior studies, our findings underscored good tolerability of DLAs. In comparison to other studies based on identification of CTCs by epithelial markers [ 5 , 6 ], our unbiased approach, focusing on depletion of HPCs and endothelial cells, led to the identification of large numbers of CTC, many of them with low or no EPCAM expression (Fig. 1 J).…”

“…Recent reports suggest that diagnostic leukapheresis (DLA) holds potential for increasing CTC numbers [ 5 ]. The underlying assumption is that CTCs share density and cell size similarities with mononucleated cells (MNCs), making their collection feasible via leukapheresis [ 6 ].…”

Development of liquid biopsy in detection and screening of pancreatic cancer

“…However, the CTC detection rate of the CellSearch ® system in pancreatic cancer is as low as 26% (19). Stoecklein et al improved the sensitivity of CellSearch ® system detection by using diagnostic leukapheresis (DLA), significantly improving the detection rate of CTC in M0 and M1 patients with pancreatic cancer, with 44% and 74% respectively, resulting in a 60 fold increase in CTCs count (20).…”

A real-world comparison of circulating tumor cells in breast cancer from China: Novel device, CTC counts and its overall survival

“…Although CTC detached from blood have been discovered since 150 years ago, it was not until Cellsearch (CS) was developed that specific detection and molecular examination of CTC have gained heightened attention. Afterwards, many researches have proven the strong associations between CTC counts and survival in metastatic breast cancer and many other cancers [ 2 , 3 ]. This may be explained by the fact that technology improvements may pose a tremendous challenge to enable more consistent CTC isolation [ 4 ].…”