BACKGROUND The optimal maintenance therapy for RAS and BRAF metastatic colorectal cancers (mCRC) remains unclear. It is critical to evaluate the reliability of the observation group (cetuximab-capecitabine) relative to the control (capecitabine) as a treatment to maintain. PATIENTS AND METHODS In this retrospective analysis, patients with RAS and BRAF mCRC admitted to the Department of Medical Oncology, Huizhou Municipal Central Hospital, from January 2016 to October 2020 were enrolled and treated with cetuximab plus FOLFIRI as an initial therapy. Patients whose disease was controlled after at least six cycles of treatment were administered a maintenance therapy until disease progression. Analyze the prognosis of patients according to clinicopathological features. Altogether, 39 RAS and BRAF mCRC patients were recruited from January 2016 to October 2020, with 18 cases in the treatment group and 21 cases in the control group. The difference is not obvious in baseline clinicopathological features between the two treatments. RESULTS The median PFS after maintenance treatment in observation group (9.5 months, [95% CI=6.4-12.6]), was significantly better than the control group (7.3 month, [95% CI=5.8-8.8]). During maintenance treatment, there were no deaths caused by treatment-related adverse events, and the overall incidence of rash acne was obviously different between the observation and control groups (p < 0.05). Most adverse events were mild and easily controlled. Primary tumor site, baseline CEA levels, and MSI status were independent prognostic factors. CONCLUSION A maintenance therapy using cetuximab plus capecitabine improved survival in patients with metastatic CRC and is well tolerated by patients.

中文翻译：

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一项真实世界回顾性研究，旨在评估西妥昔单抗联合卡培他滨与卡培他滨作为 RAS 和 BRAF 野生型转移性结直肠癌患者维持治疗的可靠性。

背景 RAS 和 BRAF 转移性结直肠癌 (mCRC) 的最佳维持治疗仍不清楚。评估观察组（西妥昔单抗-卡培他滨）相对于对照组（卡培他滨）作为维持治疗的可靠性至关重要。患者和方法在这项回顾性分析中，纳入2016年1月至2020年10月惠州市市中心医院肿瘤内科收治的RAS和BRAF mCRC患者，并接受西妥昔单抗联合FOLFIRI作为初始治疗。经过至少六个治疗周期后疾病得到控制的患者接受维持治疗直至疾病进展。根据临床病理特征分析患者的预后。2016年1月至2020年10月期间，共招募了39例RAS和BRAF mCRC患者，其中治疗组18例，对照组21例。两种治疗之间的基线临床病理特征差异并不明显。结果观察组维持治疗后中位PFS（9.5个月，[95% CI=6.4-12.6]）明显优于对照组（7.3个月，[95% CI=5.8-8.8]）。维持治疗期间，没有出现因治疗相关不良事件导致的死亡，观察组和对照组之间皮疹痤疮的总体发生率存在明显差异（p < 0.05）。大多数不良事件都很轻微且易于控制。原发肿瘤部位、基线 CEA 水平和 MSI 状态是独立的预后因素。结论 使用西妥昔单抗联合卡培他滨维持治疗可改善转移性 CRC 患者的生存率，并且患者耐受性良好。