MSCT-based Assessment Of Effects Of Preoperative Chemotherapy With SOX Regimen For Advanced Gastric Cancer

Objective: Although the global incidence of gastric cancer is declining,the mortality rate remains high, which is because most gastric cancers arefound at an advanced stage. Present domestic and foreign clinical researchesshowed that preoperative chemotherapy in the treatment of advanced gastriccancer could effectively improve the R0resection rate and prolong thesurvival time of the patients. Objective and accurate evaluation can help withselecting treatment plan and estimating prognosis. Thus, the followingmethods are widely used to assess the effects of chemotherapy, including:analysis of TNM staging changes before and after chemotherapy for gastriccancer, RECIST evaluation criterions, the use of MSCT post-processingtechniques in measuring tumor volume as well as density.In this study, we performed MSCT enhancement scan, recorded TNMstaging before and after chemotherapy, used MSCT post-processingtechniques to measure tumor volume, density and longest axial diameter(LAD), analyzed variations in data in groups as well as discussed clinicalimaging efficacy on preoperative chemotherapy with SOX regimen foradvanced gastric cancer.Methods: A total of50patients with gastric adenocarcinoma confirmedby gastroscopy biopsy in Fourth Hospital of Hebei Medical University fromNovember2011to January2014were enrolled in this study, which including40male cases and10female cases, aged from39-77years old with the medianage of59years old. These patients with cT3-4N0-3M0were confirmed by MSCTenhancement scan1week before chemotherapy, received2-4cycles of SOXchemotherapy, and underwent MSCT enhancement scan again1week afterchemotherapy. Analyzed data variations in groups by recording TNM stagingbefore and after chemotherapy, and measuring volume, density and the LAD of tumor. We estimated TNM staging according to the7thedition AJCC TNMstaging system for gastric cancer, and observed clinical staging changes beforeand after chemotherapy. Efficacy of the LAD was evaluated by RECIST1.1criterions, which include Complete Response (CR), Partial Response (PR),Stable Disease (SD) and Progressive Disease (PD), while estimating effectiverate of preoperative chemotherapy as well as tumor control probability.According to the conclusions of this preliminary experiment, we defined thereduction rate of tumor volume and that of density with11.73%and10.43%respectively as the critical value of chemotherapy effectiveness. We usedSPSS17.0to analyze data from the study, which showed significantdifferences (P<0.05).Results：150patients treated with SOX chemo regimen were evaluated byRECIST1.1criterions, which including: CR1case (2%), PR20cases (52%),SD26cases (52%), and PD3cases (6%). The total effective rate (CR+PR)was42%(21/50); tumor control probability (CR+PR+SD) was94%(47/50).2TNM staging before chemotherapy: Ⅱb8cases, Ⅲa20cases, Ⅲb18cases, Ⅲc4cases; TNM staging after chemotherapy: Ⅰa2cases, Ⅰb1case,Ⅱa9cases, Ⅱ b11cases, Ⅲa16cases, Ⅲb11cases.TNM staging afterchemotherapy was degraded compared to that before chemotherapy (P<0.05).There were25patients received clinical TNM downstaging, thus the tumordownstaging rate was50%(25/50).3T stage before chemotherapy: T34cases, T446cases; T stage afterchemotherapy: T11case, T23cases, T311cases, T435cases, T stage afterchemotherapy was degraded compared to that before chemotherapy (P<0.05);N stage before chemotherapy: N07cases, N123cases, N219cases, N31case; N stage after chemotherapy: N020cases, N119cases, N211cases, Nstage after chemotherapy was degraded compared to that before chemotherapy(P<0.05).4Tumor volume after chemotherapy (46.90±31.77cm3) was decreasedcompared to that before chemotherapy (57.74±33.65cm3)(P=0.000); tumor density after chemotherapy (66.25±11.26HU) that before chemotherapy(75.68±11.75HU)(P=0.000).5Reduction rate of total tumor volume was20.4%±21.45%, reductionrate of total tumor density was12.0%±10.8%.6In50patients treated with SOX chemo regimen, the reduction rate oftumor volume in74%(37/50) patients exceeded11.73%, thus thechemotherapy was determined effective; the reduction rate of tumor density in56%(28/50) patients exceeded10.43%, thus the chemotherapy wasdetermined effective.Conclusions：1Preoperative chemotherapy with SOX regimen can significantlydegrade tumor clinical TNM staging.2Preoperative chemotherapy with SOX regimen can significantlydecrease the tumor LAD of MSCT.3Preoperative chemotherapy with SOX regimen can significantlydecrease tumor volume and density of MSCT. It is highly effective to evaluateefficacy of preoperative chemotherapy with SOX regimen by clinical imaging,therefore, this treatment is worth to be popularized.