TP53 mutations remained significant predictors of tumor progression during FOLFIRINOX after adjusting for stage of disease and baseline CA 19-9 level: OR 10.51 (95% CI 1.40–79.14, p = 0.022) for detection of TP53 ctDNA mutations before start chemotherapy and OR 6.98 (95% CI 1.31–37.30, p = 0.023) for a homozygous TP53 Pro72Arg variant presence. This evidence concerns the gene TP53 and neoplasm.