Application value of multi-detector computed tomography evaluating the clinical staging of adenocarcinoma of the esophagogastric junction after neoadjuvant chemotherapy / 中华消化外科杂志

ABSTRACT

Objective To investigate the multi-detector computed tomography (MDCT) evaluating the clinical staging of adenocarcinoma of the esophagogastric junction (AEG) after neoadjuvant chemotherapy.Methods The retrospective cross-sectional study conducted.The clinicopathological data of 46 AEG patients who were admitted to the Peking University Cancer Hospital between January 2016 and April 2018 were collected.All patients underwent MDCT before and after neoadjuvant chemotherapy and at preoperative 2 weeks,the distance between tumor center and boundary of esophagogastric junction (EGJ) was judged through coronal measured values and axial formula method.Patients underwent radical resection of gastric cancer + D2 lymph node dissection after neoadjuvant chemotherapy,pathologists reviewed the distance between center of AEG and boundary of EGJ,T staging (ycT) and N staging (ycN) of clinical staging,T staging (ypT) and N staging (ypN) of pathological staging after neoadjuvant chemotherapy were determined according to TNM staging of American Joint Committee on Cancer (AJCC) (8th edition),and tumor regression grading (TRG) was determined according to the criterion established by National Comprehensive Cancer Network.Observation indicators:(1) CT examination after neoadjuvant chemotherapy;(2) clinical staging after neoadjuvant chemotherapy;(3) postoperative pathological examination;(4) postoperative pathological staging;(5) accuracy of clinical staging after neoadjuvant chemotherapy;(6)relationship between imaging changes of CT examination and pathological reactions.Count data were described as absolute number or percentage,and comparisons among groups were analyzed by the chi-square test.Comparisons of ordinal data were analyzed by the non-parametric test.Results (1) CT examination after neoadjuvant chemotherapy:5 of 46 AEG patients,coronal images of CT showed whole tumor and boundary of EGJ,axial images of CT showed EGJ wall thickening,heterogeneous enhancement in all layers of lesions,and unsmooth serosal surface;the distance between tumor center and boundary of EGJ is less than 2 cm by direct measurement,5 patients were confirmed as esophageal cancer staging.For 41 patients,the same coronal image of CT cannot showed whole tumor and boundary of EGJ,axial images of CT showed EGJ wall thickening,heterogeneous enhancement in all layers of lesions,and irregular-shaped serosal surface;27 patients whose calculated values were negative based on formula method used esophageal cancer staging,and 14 patients whose calculated values were positive used gastric staging.(2) Clinical staging after neoadjuvant chemotherapy:among 46 AEG patients,ycT staging:staging ycT1,ycT2,ycT3,ycT4a and ycT4b were respectively detected in 1,6,31,6 and 2 patients;ycN staging:staging ycN0,ycN1,ycN2 and ycN3a were respectively detected in 5,14,23 and 4 patients.(3) Postoperative pathological examination:of 46 patients,38,3,3 and 2 were respectively confirmed as adenocarcinoma,adenocarcinoma with signet-ring cell carcinoma,adenocarcinoma with neuroendocrine carcinoma and adenocarcinoma with squamous carcinoma.Of 46 patients,the distance between tumor center and boundary of EGJ can be observed in 14 patients by gastric cancer staging and 32 patients by esophageal cancer staging.(4) Postoperative pathological staging:ypT staging:1,3,5,29,7 and 1 patients were respectively detected in staging ypT0,ypT1,ypT2,ypT3,ypT4a and ypT4b;ypN staging:17,4,15,9 and 1 patients were respectively detected in staging ypN0,ypN1,ypN2,ypN3a and ypN3b.One,3,16 and 26 patients were confirmed as staging TRG 0,TRG 1,TRG 2 and TRG 3,including 20 patients tumor regression and 26 patients without tumor regression.(5) Accuracy of clinical staging after neoadjuvant chemotherapy:the accuracies of ycT staging and ycN staging were 78.3％ (36/46) and 54.3％ (25/46).(6) Relationship between imaging changes of CT examination and pathological reactions:of 46 patients,33 and 13 had respectively reduced and stable gastric wall thickness of primary lesion.Among 20 patients with tumor regression,17 and 3 had respectively reduced and stable gastric wall thickness of primary lesion;of 26 patients without tumor regression,reduced and stable gastric wall thickness of primary lesion were respectively in 16 and 10 patients,with no statistically significant difference (x2 =3.069,P＞0.05).Of 46 patients,31,14 and 1 had respectively reduced,stable and increased sum of minor diameters of suspicious celiac lymph nodes.The reduced,stable and increased sum of minor diameters of suspicious celiac lymph nodes were detected in 16,4,0 of 20 patients with tumor regression and 15,10,1 of 26 patients without tumor regression,respectively,with no statistically significant difference (Z =-1.629,P＞ 0.05).The changes of gastric wall thickness of primary lesion and sum of minor diameters of celiac lymph nodes before operation were not consistent to that after operation in 3 patients.CT examination showed gastric wall thickness of primary lesion reduced after chemotherapy,and sum of minor diameters of celiac lymph nodes didn't change;pathological staging and clinical staging were respectively in staging ypN0 and ycN1.Conclusion According to the TNM staging of AJCC (Sth edition),the distance between tumor center and boundary of EGJ is judged through coronal measured values and axial formula method and therefore determining to select staging system of esophageal cancer or gastric cancer,meanwhile,rectifying over T3 staging of Siewert Ⅱ gastric cancer and increasing overall accuracy of clinical staging.