Second-line therapy adjustment for advanced pancreatic cancer using circulating tumor cells: Preliminary results

Cancer Treat Res Commun. 2025 Jun 20:44:100956. doi: 10.1016/j.ctarc.2025.100956. Online ahead of print.

Abstract

Background: The determination of the optimal second-line (2L) chemotherapy for advanced pancreatic cancer (APC) is still unanswered. We aimed to assess the effectiveness of circulating tumor cells (CTCs) in proposing 2L treatments for APC.

Methods: We analyzed CTCs from 17 patients (experimental group) with APC, for whom first-line treatment was ineffective. Based on chemosensitivity/viability assays on several chemotherapeutic drugs, which were performed on CTCs isolated from patients, a 2L treatment was proposed for each patient. Median survival (MS) was used as the primary endpoint to compare the survival curve of the experimental group with the reconstructed survival curves of two 2L best supportive care (2L-BSC) groups with 23 and 18 patients, respectively. Moreover, using a meta-analysis of 2L-BSC summary statistics (medians) published in various papers, a pooled weighted MS was estimated and compared with one estimated for the experimental group. Finally, the statistical significance of the difference between the experimental and the two 2L-BSC groups was examined by applying statistical tests, like LR and RMST.

Results: The MS for the treatment group (7 months) was found to be greater than the MS of the two 2L-BSC groups (2.29 and 2.4 months, respectively). This result was supported since the weighted MS was found at 2.70 months. The results were found statistically significant.

Conclusions: The preliminary results indicate that 2L treatment based on CTCs' response in vitro prolongs MS of APC patients compared with 2L-BSC-treated ones, potentially leading to the development of more effective 2L APC therapy plans.

Keywords: 2L therapy; APC; CTCs; HR; LR tests.