Tao L, Su L, Yuan C, et al. - Whether flow cytometry (FCM) detection of portal vein circulating tumor cells (CTCs) is valuable for predicting postoperative metastasis was investigated. Researchers gathered samples of portal venous blood and peripheral blood from 39 patients during surgery. FCM was used to identify CTCs. Laser confocal microscopy and single-cell sequencing were used as a means for confirmation. Significant predictors of metastasis detected in all patients were: a portal EpCAM+CD45- percentage ≥ 24.5×10⁻⁴, peripheral EpCAM+CD45- count ≥ 97/5 mL, peripheral EpCAM+CD45- percentage ≥ 4.4×10⁻⁴, and CA242 ≥ 3.5 U/mL. Metastasis in pancreatic cancer post-curative resection was predicted by portal EpCAM+CD45- ratio ≥ 24.5×10⁻⁴. Findings highlighted the significant value of FCM-detected CTCs in portal venous blood for the prediction of postoperative metastasis in pancreatic or periampullary tumors.