[Enhancing survival outcomes in stage â ¢ gastric/esophagogastric junction cancer: a retrospective study of immune checkpoint inhibitors and adjuvant chemotherapy based on real-world data].

Objective: To explore the efficacy of immune checkpoint inhibitors combined with adjuvant chemotherapy in patients with phase III gastric cancer and esophagogastric junction cancer. Methods: This study used a retrospective cohort study method based on real-world data. Clinical data of 403 patients with stage III gastric/esophagogastric junction cancer who underwent gastrectomy followed by adjuvant therapy in the Department of Gastric Surgery at Sun Yat-sen University Cancer Center from January 2020 to December 2023 were retrospectively collected. The study cohort comprised 147 (36.5%) patients with stage IIIA, 130 (32.3%) with stage IIIB, and 126 (31.3%) with stage IIIC gastric/esophagogastric junction cancer. Of them, 15 (3.7%) were HER-2 positive, 25 (6.2%) dMMR, and 22 (5.5%) patients Epstein-Barr virus encoding RNA (EBER) positive. Based on treatment plans, the patients were divided into immune checkpoint inhibitor combined with chemotherapy group (immune therapy group, n=110, 71 males and 39 females, median age 59 years old) and chemotherapy alone group (chemotherapy group, n=293, 186 males and 107 females, median age 60 years old). All patients in the immunotherapy group received immune checkpoint inhibitors targeting the programmed cell death protein-1 (PD-1) and its ligand (PD-L1). Of them, 85 received pembrolizumab, 10 received sintilimab, 8 received tislelizumab, 4 received camrelizumab, 2 received toripalimab, and 1 received pabocizumab. The adjuvant chemotherapy regimens used among the chemotherapy alone group includes SOX regimen (132 cases), XELOX (102 cases), S-1 monotherapy (44 cases), and other regimens (15 cases). The 3-year DFS rate of the two groups was compared, and subgroup analysis was conducted based on different ages, molecular phenotypes, pTNM staging, extranodal infiltration, and tumor length. Results: The median follow-up was 20.5 months (range 3.1~46.3), with a 3-year overall DFS rate of 61.4% for the entire 403 patients. The 3-year DFS rate for the immunotherapy group was 82.7%, higher than the chemotherapy alone group (58.8%), with a statistically significant difference (P=0.021). Multivariate analysis showed that postoperative immunotherapy was a protective factor for DFS (HR=0.352, 95%CI: 0.180~0.685). Subgroup analysis showed that stage IIIC (HR=0.416, 95%CI: 0.184~0.940), aged ≥60 years (HR=0.336, 95%CI: 0.121~0.934) and extranodal invasion (HR=0.378, 95%CI: 0.170~0.839) were associated with benefit from the combined immune adjuvant chemotherapy, while no association was observed for MMR, HER-2 or EBER status. Conclusion: Stage III gastric/esophagogastric junction cancer patients may benefite from postoperative immune checkpoint inhibitor combined with adjuvant chemotherapy in real-world settings.

The role of Sep (O-phosphoserine) tRNA: Sec (selenocysteine) synthase (SEPSECS) in proliferation, apoptosis and hormone secretion of trophoblast cells.

OBJECTIVES: To investigate whether Sep (O-phosphoserine) tRNA: Sec (selenocysteine) synthase (SEPSECS), which plays an essential role in the synthesis of selenoprotein, affects proliferation, apoptosis and hormone secretion of human trophoblast cells. METHODS: Human trophoblast JEG-3 cells were divided into four groups: control group, SEPSECS silenced-expression group, empty vector group and SEPSECS over-expression group. Over-expression and silenced-expression were achieved by transfection with plasmid DNA or RNA oligonucleotide, respectively. 3-[4,5-dimethylthiazol-2-yl] -2,5-diphenyltetrazolium bromide (MTT) and colony formation assays were performed to investigate cell proliferation, while apoptosis was tested by annexin V-FITC, PI double staining and caspases-3 activation assays, enzyme-linked immunosorbent assay (ELISA) was used to determine the level of progesterone (PG) and human chorionic gonadotropin (hCG). RESULTS: SEPSECS silenced-expression clearly inhibited proliferation of JEG-3 cells (p < 0.05), significantly induced cell apoptosis (p < 0.01) and reduced the production of PG and hCG (p < 0.05). On the contrary, SEPSECS over-expression significantly promoted both cell proliferation (p < 0.01) and secretion of PG and hCG (p < 0.05). CONCLUSIONS: SEPSECS significantly affects proliferation, apoptosis and hormone secretion of human trophoblast cells, suggesting that a potential relationship exists among SEPSECS, cell proliferation, apoptosis and hormone production of human placental trophoblast cells. Furthermore, this may provide a clue to uncover the relationship between selenium and human placental in association with an emphasis on the importance of selenium adequacy during pregnancy.