Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
Ann Surg Oncol. 2021 Dec;28(13):8908-8915. doi: 10.1245/s10434-021-10084-0. Epub 2021 Aug 16.
Microsatellite status is a prognostic biomarker in advanced gastric cancer. This retrospective study aimed to investigate the usefulness of microsatellite status in predicting prognosis and response to adjuvant treatment in pT1N1 gastric cancer.
Among 875 patients who underwent radical gastrectomy for pT1N1 gastric cancer at two tertiary hospitals, 838 with available microsatellite instability (MSI) data were included and classified into two groups according to microsatellite status: microsatellite stable (MSS) and MSI-high (MSI-H). Recurrence-free survival rate and risk factors for tumor recurrence were analyzed.
Of 838 gastric cancer patients, 100 (11.9%) were MSI-H and 307 (36.6%) received adjuvant treatment. During median follow-up of 70 months, 42 (5.0%) patients experienced gastric cancer recurrence; hematogenous recurrences were the most common (45.2%). Recurrence-free survival was similar in the MSS and MSI-H groups (p = 0.27), and adjuvant treatment did not show an oncological benefit over surgery alone for pT1N1 gastric cancer (p = 0.53). On univariate analysis, age, operation period, and Lauren classification were significantly associated with tumor recurrence, while adjuvant treatment and MSI status were not associated with tumor recurrence. On multivariate analysis, MSI status was not associated with tumor recurrence, and adjuvant treatment worsened the tumor recurrence risk [hazard ratio (HR) 2.373, 95% confidence interval (CI) 1.125-5.006, p = 0.023).
MSI status may not be a prognostic factor for tumor recurrence or a predictor of response to adjuvant treatment in pT1N1 gastric cancer patients. Considering that the effect of adjuvant treatment to decrease the risk of tumor recurrence is not clear, it may not be indicated in pT1N1 patients.
微卫星状态是晚期胃癌的一种预后生物标志物。本回顾性研究旨在探讨微卫星状态在预测 pT1N1 胃癌患者预后和对辅助治疗反应中的作用。
在两家三级医院接受根治性胃切除术的 875 例 pT1N1 胃癌患者中，纳入 838 例有微卫星不稳定性（MSI）数据的患者，并根据微卫星状态将其分为两组：微卫星稳定（MSS）和 MSI 高（MSI-H）。分析无复发生存率和肿瘤复发的危险因素。
838 例胃癌患者中，100 例（11.9%）为 MSI-H，307 例（36.6%）接受辅助治疗。中位随访 70 个月期间，42 例（5.0%）患者发生胃癌复发；血行转移是最常见的复发类型（45.2%）。MSS 和 MSI-H 两组的无复发生存率无差异（p = 0.27），辅助治疗并未显示出优于单纯手术治疗对 pT1N1 胃癌的肿瘤学获益（p = 0.53）。单因素分析显示，年龄、手术期和Lauren 分类与肿瘤复发显著相关，而辅助治疗和 MSI 状态与肿瘤复发无关。多因素分析显示，MSI 状态与肿瘤复发无关，辅助治疗增加了肿瘤复发的风险[风险比（HR）2.373，95%置信区间（CI）1.125-5.006，p = 0.023]。
MSI 状态可能不是 pT1N1 胃癌患者肿瘤复发的预后因素，也不是辅助治疗反应的预测因素。考虑到辅助治疗降低肿瘤复发风险的效果不明确，pT1N1 患者可能不需要辅助治疗。
