The value of MSCT volume measurement in neoadjuvant chemotherapy for advanced gastric cancer

Objective To evaluate the efficacy of chemotherapy and estimate the prognosis of patients with progressive gastric cancer. Methods A total of 116 patients from a prospective, multicenter, open-label, and randomized phase Ⅲ clinical trial were enrolled in the Fourth Hospital of Hebei Medical University from Dec 2012 to Jun 2015. Pre- and two weeks after neoadjuvant chemotherapy, multi-slice spiral CT was performed to calculate the percentage change of the longest diameter and tumor volume to evaluate the Recist score and tumor volume reduction rate. Spearman correlation test was used to analyze the correlation of post-volume reduction rate, Recist 1.1 score, and tumor regression grade. The ROC curve was used to find a defined value for the volume reduction rate that identifies the effectiveness of chemotherapy and assign a new grading standard. The survival curve was drawn by Kaplan-Meier method, and the relationship between the effective survival group and the ineffective group under the new grading standard was observed. Results The Recist score was moderately correlated with the pathological tumor regression scale, and the volume reduction rate after chemotherapy was strongly correlated with the pathological regression scale (R=0.579). When the tumor volume reduction rate was 12.5% as an effective threshold for evaluating neoadjuvant chemotherapy, the AUC under the ROC curve was the largest, with sensitivity and specificity of 81.1% and 75.9%, respectively. The median survival time of the effective and ineffective groups was 25 months and 18 months, respectively, and the 2-year survival rate was 73.3% and 51.2%. The total survival time of patients with effective chemotherapy was significantly longer than those with ineffective chemotherapy (P=0.003 6). Conclusion The volume measurement grading standard can predict the pathological regression of neoadjuvant chemotherapy patients, and it is superior to the Recist score in the evaluation of efficacy and prognosis. Key words: Stomach neoplasms; Tomography, spiral computed; Chemoradiotherapy, adjuvant; Prognosis