Background and purpose The clinical role of postoperative adjuvant therapy in hepatocellular carcinoma (HCC) is still unclear. The purpose of our study was to explore the clinical value of postoperative adjuvant anti-programed cell death 1 antibody (PA-PD-1) on the prognosis of HCC patients with high relapse risks after surgery. Patients and methods Data of consecutive HCC patients with high recurrence risks treated with liver resection at our center during January 2019 and March 2021 were prospectively collected. Baseline differences were balanced between HCC patients with (PA-PD-1 group) or without PA-PD-1 (non-PD-1 group) after hepatectomy by propensity-score matching (PSM). Between these two groups, we compared overall survival (OS) and recurrence-free survival (RFS). Independent prognostic risk factors for OS and RFS were confirmed by Cox regression analysis, and subgroup analysis was also performed. Results 47 pairs of patients with or without PD-1 treatment after hepatectomy were matched. After PSM, the 1-year and 2-year RFS was 58.4% and 44.1% in the PA-PD-1 group, and 34.0% and 21.3% in the non-PD-1 group (p = 0.008). The OS at 1 year and 2 years was 91.2% and 91.2% in the PA-PD-1 group, compared with 85.1% and 61.7% in the non-PD-1 group (p = 0.024). Multivariable analyses demonstrated that PA-PD-1 was an independent protective predictor associated with RFS and OS. Through subgroup analysis, we concluded that HCC patients with portal venous tumor thrombus (PVTT) or tumor size ≥ 5 cm significantly benefited from PA-PD-1 therapy in RFS and OS. Conclusions Adjuvant anti-PD-1 antibody can effectively improve the survival outcomes of HCC patients with high relapse risks after hepatectomy in this prospective observational study. This finding should be confirmed by results of the ongoing phase 3 randomized controlled trials.

The effect of different content of lysine (Lys, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, m/m) on the texture characteristics and water holding capacity (WHC) of transglutaminase (0.4%)-induced mixed surimi gels was explored. The results showed that 0.2% Lys obviously improved the gel strength, textural properties, and WHC of the mixed surimi gels (P < 0.05). However, superfluous Lys (0.4%–0.5%) played a significant negative impact. That’s because 0.2% Lys facilitated the non-covalent interactions and non-disulfide covalent interactions between surimi proteins, promoted the formation of a fine and dense gel microstructure. While high content of Lys induced the formation of excess ε-(γ-Glu)-Lys isopeptide bonds but weakened the non-covalent interactions between surimi proteins, resulting in an irregular and heterogeneous microstructure with large voids. In conclusion, moderate Lys can effectively improve the quality of mixed surimi gels, thereby providing a new and effective strategy to develop phosphorus-free surimi products.