神经旁浸润阳性胃癌患者的临床特征与预后分析

背景与目的 神经旁浸润（PNI）是胃癌局部外侵转移的生物学特性之一，其临床价值尚未得到重视。本研究旨在探讨胃癌伴发PNI的临床病理特征以及PNI对胃癌患者预后的影响。方法 回顾性分析2011年6月—2016年12月期间施行开腹根治性胃切除手术的543例胃癌患者的临床病理资料。根据癌组织PNI结果，胃癌患者分为PNI阳性组和PNI阴性组，比较两组在临床病理指标上的差异。应用倾向评分匹配法均衡两组与预后相关的基本资料变量，采用Kaplan-Meier法进行生存分析，采用Cox风险回归模型分析与PNI阳性胃癌患者术后生存相关的危险因素。结果 全组胃癌患者中PNI阳性率21.18%（115/543）。匹配前两组的肿瘤大小、肿瘤部位、细胞分化程度、肿瘤TNM分期、脉管侵犯、手术切除范围及术后辅助化疗等方面差异有统计学意义（均P<0.05）；匹配后，PNI阳性组56例，PNI阴性组98例，两组患者基线资料均衡（均P>0.05）。PNI阳性组的总生存时间（OS）明显短于PNI阴性组（中位OS：19个月vs. 49个月，P=0.002）；亚组分析显示，TNM I~II患者中，PNI阳性对OS无明显影响（P=0.432），但明显缩短III期患者的OS（中位OS：18个月vs. 2个月，P<0.001）。在PNI阳性患者中，术后辅助化疗对I~II期患者的OS无明显影响（P=0.975），但能明显延长III患者的OS（中位OS：18个月vs. 2个月，P<0.001）。单因素分析结果提示年龄（P=0.008）、TNM分期（P=0.034）和术后辅助化疗（P=0.006）与PNI阳性胃癌患者术后预后紧密相关；多因素分析发现TNM分期处于III期（HR=2.591，95% CI=1.291~5.198，P=0.007）、未进行术后辅助化疗（HR=0.345，95% CI=0.184~0.649，P=0.001）是影响PNI阳性胃癌患者预后的独立危险因素。结论 PNI阳性胃癌患者的预后明显差于PNI阴性胃癌患者，其对预后的影响在TNM III期患者中尤为明显。积极的术后辅助化疗有助于改善该类胃癌患者的预后。

Clinical characteristics and prognosis analysis of patients with positive perineural invasion gastric cancer

Background and Aims Perineural invasion (PNI) is one of the biological characteristics of local invasion and metastasis of gastric cancer, but its clinical value has not been paid much attention. The purpose of this study was to investigate clinicopathologic features in gastric cancer with PNI and the influence of PNI on prognosis of gastric cancer patients.Methods The clinicopathologic data of 543 patients with gastric cancer who underwent open radical gastrectomy were retrospectively analyzed. The patients were divided into PNI-positive group and PNI-negative group, and the differences in clinicopathologic variables between the two groups were compared. Propensity score matching was used to equalize the basic variables related to prognosis in the two groups. Survival analysis was conducted using Kaplan-Meier method and Cox proportional hazard model was used to analyze the risk factors associated with postoperative survival of PNI-positive gastric cancer patients.Results The positive rate of PNI in gastric cancer patients was 21.18% (115/543). Before matching, there were statistically significant differences in terms of tumor size, tumor site, degree of tumor cell differentiation, tumor TNM stage, presence of vascular invasion, surgical resection scope and postoperative adjuvant chemotherapy between the two groups (all P<0.05). After matching, 65 patients were allocated to PNI-positive group and 98 patients allocated to PNI-negative group, and the baseline clinicopathologic data of the two groups were well matched (all P>0.05). The overall survival time (OS) of PNI-positive group was significantly shorter than that of PNI-negative group (median OS: 19 months vs. 49 months, P=0.002); subgroup analysis showed that positive PNI exerted no significant influence on OS in TNM stage I-II patients (P=0.432), but significantly reduced the OS in stage III patients (median OS: 18 months vs. 2 months, P<0.001). In PNI-positive patients, postoperative adjuvant chemotherapy exerted no significant influence on OS in stage I-II patients (P=0.975), but significantly prolonged the OS in stage III patients (median OS: 18 months vs. 2 months, P<0.001). Univariate analysis demonstrated that age (P=0.008), tumor TNM stage (P=0.034), and absence of postoperative adjuvant chemotherapy (P=0.006) were significantly associated with the prognosis of patients with PNI-positive gastric cancer. Multivariable analysis revealed that TNM stage III (HR=2.591, 95% CI=1.291-5.198, P=0.007) and absence of postoperative adjuvant chemotherapy (HR=0.345, 95% CI=0.184-0.649, P=0.001) were independent risk factors for the prognosis of PNI-positive gastric cancer.Conclusion The prognosis of PNI-positive gastric cancer patients is poor than that of PNI-negative ones, which is particularly obvious in those with TNM stage III disease. Aggressive postoperative adjuvant chemotherapy may be helpful for improving the outcomes of these patients.