Objective: To investigate the therapeutic effect and prognosis of gastrectomy combined with chemotherapy and chemotherapy alone for treatment of advanced gastric cancer with abdominal para-aortic (the 16th) lymph node metastasis. Methods: The clinical data of 236 patients with advanced gastric cancer with abdominal para-aortic (the 16th) lymph node metastasis in Jincheng People's Hospital of Shanxi Province from January 2003 to December 2012 were retrospectively analyzed. According to the treatment method, the patients were divided into chemotherapy alone group (121 cases) and gastrectomy + chemotherapy group (115 cases), and mFOLFOX6 regimen was used for chemotherapy. The efficacy and adverse reactions of the two groups were compared. Results: The incidence of upper gastrointestinal adverse events in the gastrectomy+chemotherapy group was higher than that in the chemotherapy alone group [8.7% (10/115) vs. 1.7% (2/121)], and the difference between the two groups was statistically significant (χ ² = 3.881, P = 0.049). The median overall survival was 14.8 months (10.9-17.8 months) in the chemotherapy alone group and 11.7 months (9.8-15.6 months) in the gastrectomy+chemotherapy group, and there was no significant difference between the two groups (P > 0.05). The 2-year overall survival rate was 32.3% in the chemotherapy alone group and 24.3% in the gastrectomy+chemotherapy group, and there was no significant difference between the two groups (χ ² = 3.105, P = 0.078). The 2-year progression-free survival rate was 16.5% in the chemotherapy alone group and 20.0% in the gastrectomy+chemotherapy group, and the difference between the two groups was statistically significant (χ ² = 3.917, P = 0.047). Conclusion Compared with chemotherapy alone, advanced gastric cancer patients with abdominal para-aortic (the 16th) lymph node metastasis could not benefit from gastrectomy combined with chemotherapy.

Objective:To investigate the efficacy and safety of DOS regimen in adjuvant chemotherapy after D2 radical resection for advanced gastric adenocarcinoma.Methods:The clinical data of 130 patients who received adjuvant chemotherapy after D2 radical resection for advanced gastric adenocarcinoma in Jincheng People's Hospital from January 2017 to January 2019 were retrospectively analyzed. According to treatment regimens, the patients were divided into DOS regimen chemotherapy group (DOS group, 63 cases) and SOX (oxaliplatin, S-1) regimen chemotherapy group (SOX group, 67 cases). The short-term efficacy and adverse reactions of the two groups were compared.Results:Due to the irregular treatment time, 2 cases in each group were removed. Finally, there were 61 cases in DOS group and 65 cases in SOX group. The 1-, 2- and 3-year disease-free survival (DFS) rates of the DOS group were 80.33%, 73.77% and 62.30%, and the DFS rates of the SOX group were 73.85%, 55.38% and 41.54%. The difference in DFS between the two groups was statistically significant ( χ2 = 5.43, P = 0.022). The 1-, 2- and 3-year overall survival (OS) rates of the DOS group were 93.44%, 80.33% and 70.50%, and the OS rates of the SOX group were 96.92%, 73.85% and 52.31%. The difference in OS between the two groups was statistically significant ( χ2 = 4.38, P = 0.045). There were no statistical differences in the incidence rates of grade Ⅰ-Ⅱ nausea, vomiting, diarrhea, bone marrow suppression and fatigue between the two groups (all P > 0.05). There were no statistical differences in the incidence rates of grade Ⅲ-Ⅳ nausea, vomiting and fatigue (both P > 0.05), but there were statistical significances in the incidence rates of grade Ⅲ-Ⅳ diarrhea and bone marrow suppression (both P < 0.05). Conclusions:Adjuvant DOS regimen in the treatment of advanced gastric adenocarcinoma after D2 radical resection has good curative efficacy and can improve the survival of patients, and the adverse reactions can be tolerated.

Clustered regularly interspaced short palindromic repeats (CRISPR) are acquired immune system in bacteria and archaea. This system is used in site-directed gene editing. Recently, scientists discovered new CRISPR-associated (Cas) proteins, in which Cas12a-mediated gene editing can significantly reduce the off-target rate. In this article, we review CRISPR/Cas system's discovery of history, composition, classification, and working principle. The latest research progress of the CRISPR/Cas system, and its application in zebrafish are introduced.