摘要目的:评估临床TNM（cTNM）分期判断病理TNM（pTNM）分期的准确性，探索胃癌新辅助化疗的潜在获益人群。方法:采用回顾性单臂队列研究。连续纳入2013年7月至2019年4月期间，北京大学肿瘤医院胃肠肿瘤中心一病区收治的确诊为胃腺癌、行开腹或腹腔镜D 2胃癌根治手术治疗、且cTNM和pTNM确定的患者，排除术中淋巴结清扫数目<16枚、或既往行胃手术、或术前放化疗者。术前cTNM分期由影像科医生依据腹盆腔增强CT进行判读，术后pTNM分期来自患者术后病理报告结果。比较cTNM分期与pTNM分期的符合率并分析pⅠ期患者的cTNM分期情况，如cTNM分期组合对应pⅠ期比例<5%，则认为其是新辅助化疗的潜在获益人群。进一步研究临床特征与分期符合度之间的关系。 结果:共459例患者纳入分析，男性321例（69.9%），女性138例（30.1%），平均年龄60（23~85）岁。cT分期与pT分期的符合率从T 1~4期分别为82.5%（33/40）、31.1%（28/90）、34.4%（62/180）和55.0%（96/149）。cN分期与pN分期的符合率N 0~3期分别为58.8%（134/228）、22.1%（19/86）、23.6%（26/110）和54.3%（19/35）。本研究中，现有分期手段对于淋巴结转移的敏感性和特异性分别为64.5%（171/265）和69.1%（134/194）。本组cT 3~4患者中，对应pⅠ期比例为9.1%（30/329），对应pⅢ期的敏感性为94.8%（164/173）；本组cT 3~4+cN 1~3患者中，对应pⅠ期比例为1.4%（3/218），对应pⅢ期患者的敏感性为76.9%（133/173）。肿瘤位置与cT/pT分期一致有关[胃食管结合部：64例（56.6%），胃上部：9例（9/17），胃中部：31例（40.3%），胃下部：97例（39.9%），全胃：4例（4/9），χ 2=9.845， P=0.043]，肿瘤分化程度与cN/pN分期一致有关[低分化：94例（42.3%），中分化：92例（41.1%），高分化：12例（12/13），χ 2=13.261， P=0.001]，差异均有统计学意义（均 P<0.05）。 结论:基于北京大学肿瘤医院单中心回顾性数据，胃癌新辅助化疗的潜在获益人群为cT 3~4+N 1~3期患者。

abstractsObjective:To evaluate the accuracy of the clinical staging by comparing preoperative clinical stage and pathological stage in gastric cancer patients, and to explore the potential beneficial population of neoadjuvant chemotherapy for gastric cancer.Methods:We retrospectively collected the clinical data of consecutive patients with gastric cancer who met the inclusion criteria (gastric adenocarcinoma, undergoing laparoscopic or open D2 radical operation, definite cTNM and pTNM) for admission of the Gastrointestinal Center of Peking University Cancer Hospital from July 2013 to April 2019. Patients with the number of harvested lymph nodes less than 16, history of gastric operation or preoperative radiochemotherapy were excluded. Preoperative clinical stage was obtained from abdominal and pelvic enhanced CT by radiologists, and postoperative pathological stage was derived from postoperative pathology reports. The concordance rate between preoperative clinical stage and postoperative pathological stage, and the proportion of pathological stage I in patients with specific preoperative clinical TNM stage were analyzed and compared. The potential beneficial population of neoadjuvant chemotherapy were considered as pI < 5%. Relationship between clinical features and concordance rate of stage was further analysed.Results:A total of 459 patients were included in the analysis, including 321 males and 138 females with mean age of 60 (23 to 85) years old. The concordance rate from T1 to T4 between preoperative clinical T staging and postoperative pathological T staging was 82.5% (33/40), 31.1% (28/90), 34.4% (62/180), and 55.0% (96/149), respectively. The concordance rate from N0 to N3 between preoperative clinical N staging and postoperative pathological N staging was 58.8% (134/228), 22.1% (19/86), 23.6% (26/110), and 54.3% (19/35), respectively. The sensitivity and specificity of abdominal enhanced CT in the diagnosis of lymph node metastasis were 64.5% (171/265) and 69.1% (134/194) respectively. The clinical stage of cT3/T4 patients with pathological stage I was 9.1% (30/329), and the sensitivity of corresponding pathological stage III was 94.8% (164/173), while the cT3/4+cN1-3 patients with pathological stage I stage was 1.4% (3/218), and the sensitivity of corresponding pathological phase III was 76.9% (133/173). Tumor location was associated with the concordance of cT/pT staging [gastroesophageal junction: 64 (56.6%), upper stomach: 9 (9/17), middle stomach: 31 (40.3%), lower stomach: 97 (39.9%), whole stomach: 4(4/9), χ 2=9.845, P=0.043]; the degree of tumor differentiation was associated with the concordance of cN/pN staging [poorly differentiated: 94 (42.3%), moderated differentiated: 92 (41.1%), well differentiated: 12 (12/13), χ 2=13.261, P=0.001], whose differences were statistically significant (all P<0.05). Conclusion:Based on a single-center retrospective data from Peking University Cancer Hospital, we think that the potential beneficial population of neoadjuvant chemotherapy for gastric cancer are those clinically staged as cT3/4+N1-3.