应用倾向评分匹配法探讨癌结节对胃癌预后的影响

Application of Propensity Score Matching Method to Explore the Influence of Tumor Deposits on the Prognosis of Gastric Cancer

摘要: 目的：探讨癌结节(tumor deposits, TDs)对胃癌预后的影响。方法：研究采取回顾性病例对照研究方法，收集2015年1月1日至2019年10月30日在青岛市立医院行根治性手术治疗的胃癌患者445例的临床病理资料，根据TDs是否为阴性，分为TDs阳性组(61例)和TDs阴性组(384例)。应用倾向评分匹配法(PSM)对患者的年龄、性别、术前CEA、术前Ca199、肿瘤部位、T分期、神经侵犯、脉管癌栓、腹水状态、肿瘤大小和转移淋巴结数量11个因素按照最小半径法1:2进行匹配。采用Kaplan-Meier法进行生存分析，两组间生存率的比较，采用log⁃rank检验；采用Cox回归分析进行多因素分析。分析TDs对胃癌患者3年生存的影响。结果：匹配后，TDs阳性组44例，TDs阴性组73例，两组患者基线资料均衡(均P > 0.05)。全组中位随访时间为43.0 (10.0~86.0)个月，TDs阳性组中有28例(63.6%)死亡，其中28例死于胃癌；TDs阴性组中，30例(41.1%)死亡，其中29例死于胃癌，1例死于其他疾病。TDs阳性组患者3年生存率低于阴性组(54.5%比82.2%)，差异有统计学意义(χ² = 10.404, P = 0.001)。不同TDs数量亚组分析提示：在3年总体生存率方面，多发TDs组低于单发TDs组(37.5%比75.0%，χ² = 6.148, P = 0.013)。单因素分析结果提示：T分期(P = 0.004)、术前Ca199升高(P = 0.017)、肿瘤大小(P = 0.012)、N分期(P < 0.001)、TDs (P = 0.014)与本组胃癌患者预后有关。多因素分析提示：TDs阳性(HR = 2.258, 95%CI: 1.288~3.960, P = 0.004)、肿瘤直径 > 6 cm (HR = 2.463, 95%CI: 1.351~4.491, P = 0.003)、T分期高(HR = 1.972, 95%CI: 1.160~3.351, P = 0.012)以及N分期高(HR = 6.017, 95%CI: 3.862~9.373, P < 0.001)是影响胃癌预后的独立危险因素。结论：TDs阳性是影响胃癌患者预后的独立危险因素，临床中可采取针对性治疗措施。

Abstract: Objective: To investigate the influence of tumor deposits (TDs) on the prognosis of gastric cancer. Methods: A retrospective case-control study was conducted to collect the clinicopathological data of 445 patients with gastric cancer who underwent radical surgery in Qingdao Municipal Hospital from January 1, 2015 to October 30, 2019. According to the TDs status, they were divided into TDs posi-tive group (61 cases) and TDs negative group (384 cases). Eleven factors including age, sex, pre-operative CEA, preoperative CA19-9, tumor site, T stage, nerve invasion, vascular tumor thrombus, ascites status, tumor size, and the number of metastatic lymph nodes were matched according to the minimum radius method (PSM) of 1:2. Kaplan Meier method was used to analyze the survival rate, and log-rank test was used to compare the survival rate between the two groups. Cox regres-sion analysis was used for multivariate analysis, to analyze the effects of TDs on gastric cancer pa-tients for 3 years survival impact. Results: After matching, there were 44 cases in TDs positive group and 73 cases in TDs negative group. The baseline data of patients in the two groups were balanced (P > 0.05). The median follow-up time was 43.0 (10.0~86.0) months in the whole group. Twenty-eight cases (63.6%) in the TDs positive group died, of which 28 cases died of gastric cancer. In the TDs-negative group, 30 cases (41.1%) died, including 29 cases of gastric cancer and 1 case of other diseases. The 3-year survival rate of TDs positive group was lower than that of TDs negative group (54.5% vs 82.2%) (χ² = 10.404, P = 0.001). Subgroup analyses with different numbers of TDs suggested that in terms of 3-year overall survival rate, the multiple-TDs group was lower than the single-TDs group (37.5% vs 75.0%, χ² = 6.148, P = 0.013). The results of univariate analysis sug-gested that T stage (P = 0.004), preoperative increased CA19-9 (P = 0.017), tumor size (P = 0.012), N stage (P < 0.001), and TDs (P = 0.014) were related to the prognosis of gastric cancer in this group. Multivariate analysis revealed that positive TDs (HR = 2.258, 95%CI: 1.288~3.960, P = 0.004), tu-mor diameter > 6 cm (HR = 2.463, 95%CI: 1.351~4.491, P = 0.003), high T stage (HR = 1.972, 95%CI: 1.160~3.351, P = 0.012) and high N stage (HR = 6.017, 95%CI: 3.862~9.373, P < 0.001) were inde-pendent prognostic factors for gastric cancer. Conclusion: According to propensity score matching, perigastric TDs positive is an independent risk factor affecting the prognosis of gastric cancer pa-tients. Targeted treatment measures can be taken in clinic.