Clinical Efficacy Of Surgical Treatment For Simultaneous Liver Metastasis Of Gastric Cancer After Conversion Therapy

Objective:To analyze and compare the clinical effect of two different treatment modes for patients with simultaneous liver metastasis of gastric cancer,to explore the clinical effect of conversion therapy for patients with simultaneous liver metastasis of gastric cancer and to provide clinical data for standardized treatment.Methods:The clinical data of 24 patients with simultaneous liver metastasis of gastric cancer in the first affiliated hospital of Anhui Medical University from January 2015 to January 2018 were collected retrospectively.These patients were divided into conversion treatment group and simple operation group.In the conversion treatment group,11 patients with the conditions of transformation underwent chemotherapy transformation under the guidance of multidisciplinary therapy.When these patients were ready for surgery,they underwent curative surgery（R₀or R₁）for gastric cancer,followed by chemotherapy.Thirteen patients in the simple operation group were treated with gastrectomy（R₀or R₁）and postoperative chemotherapy.Observation indictators:（1）Evaluation of preoperative chemotherapy effect in the conversion group（complete response,partial response,stable disease,progressive disease）.（2）The intraoperative and postoperative conditions of the two groups:operative methods,intraoperative conditions（operative time,amount of intraoperative bleeding,number of lymph node dissection,degree of surgical clearance）and postoperative conditions（postoperative complications and hospital stay）.（3）The follow-up and survival condition of the 2groups were compared.（4）Analysis of factors influencing the prognosis of patients with simultaneous liver metastasis of gastric cancer.The patients were followed up by We Chat,telephone,letter and out-patient clinic to record the survival status after operation.The survival time was recorded from the beginning of the first chemotherapy in the conversion Group,or from the date of surgery in the simple operation group.The end time was the follow-up time or the time of death.All patients were followed up until August 2020.Excel and SPSS24.0 software were used for statistical analysis,and it（P<0.05）was statistically significant.The Kaplan-Meier method was used to calculate the cumulative survival rate of the two groups of patients.The overall survival analysis of the two groups of patients was compared using the Log-rank test.The COX proportional hazard model was used for univariate and multivariate analysis.Results:（1）Evaluation of the efficacy of preoperative chemotherapy in the conversion treatment group:7 of the 11 patients with liver metastases disappeared and 2 of the 11patients with most liver metastases disappeared.The 2 patients’liver metastases were under control.There were no cases of disease progression and no deaths related to chemotherapy.Through preoperative chemotherapy,8 patients were downgraded,with a downstage rate of 72.73%（8/11）,the accuracy of T staging under enhanced CT was81.82%（9/11）,and the accuracy of N staging was 63.64%（7/11）.There was no significant difference between the effective remission rate assessed by MDT and the criteria assessed by Pathology（P>0.05）.（2）Intraoperative and postoperative conditions in the conversion treatment group:Of the 11 patients,10 had radical total gastrectomy and Roux-en-Y anastomosis of esophagus and jejunum,and 1 case had radical distal subtotal gastrectomy and Roux-en-Y anastomosis of remnant stomach and jejunum.The average number of lymph nodes dissected per patient was 21.00,and the positive lymph node metastasis rate was 23.81%（55/231）.The average operation time,average blood loss and average hospital stay of each patient were 204.09 min,124.55 ml and 8.82 days,respectively.9 patients had R₀resection,and 2 patients had R₁resection.All 11 patients successfully completed the operation without postoperative complications.（3）Intraoperative and postoperative conditions in the simple operation group:10 of the 13 patients had radical total gastrectomy and Roux-en-Y anastomosis of remnant stomach and jejunum（Including 4 cases of combined liver metastasis resection）;2 of the 13 patients had radical distal subtotal gastrectomy and Roux-en-Y anastomosis of remnant stomach and jejunum;1 of the 13 patients had radical distal subtotal gastrectomy and BillrothⅡanastomosis of remnant stomach and jejunum.The average number of lymph nodes dissected per patient was 20.54 and the positive lymph node metastasis rate was 22.10%（59/267）.The average operation time,average blood loss and average hospital stay of each patient were 214.85 min,105.38 ml and 8.46day,respectively.4 patients had R₀resection and 9 patients had R₁resection.None of the 13 patients had postoperative complications and were discharged successfully.（4）Comparison of follow-up and survival of the two groups of patients:All 24 patients were followed up,and the median follow-up time was 50（37-67）months.The 3-year cumulative survival rates of patients in the conversion treatment group and the simple operation group were 27.27%and 7.69%,respectively.The difference between the two groups was statistically significant（P=0.026,P<0.05）.Further analysis found that the3-year cumulative survival rate of 13 patients with R0 resection was 30.77%,and the3-year cumulative survival rate of 11 patients with R1 resection was 0.00%.The difference of cumulative survival rate between the two groups was statistically significant（P=0.000,P<0.05）.（5）The results of a univariate analysis affecting the prognosis of patients with simultaneous liver metastases of gastric cancer showed that conversion therapy can effectively prolong the survival time of patients and is an important factor affecting the prognosis.The patient’s T stage（≤4a/4b）,N stage（≤2/3）,D₂lymph node（negative/positive）,surgical group（conversion treatment group/simple operation group）,and radical tumor resection（R₀/R₁）are related factors affecting the prognosis（P=0.001,0.019,0.027,0.033,0.001,all P<0.05）.The results of multivariate analysis showed that the degree of radical surgery of the patient was R₁,which was an independent risk factor for poor prognosis（P=0.033,P<0.05）.Conclusion:Conversion treatment can improve the survival rate of patients with simultaneous liver metastasis of gastric cancer,and R₁resection is an independent risk factor for poor prognosis.