The influence of socioeconomic position on adjuvant treatment of stage III colon cancer: a systematic review and meta-analysis

Patients with colon cancer (CC) with low socioeconomic position (SEP) have a worse survival than patients with high SEP. We investigated the association between different socioeconomic indicators and the steps in the treatment trajectory leading to initiation of adjuvant chemotherapy (ACT) for patients with stage III CC. A systematic review and meta-analyses were conducted in accordance with the MOOSE checklist. MEDLINE and EMBASE were searched for eligible studies. Meta-analyses were performed on the separate socioeconomic indicators with the random-effects model. The heterogeneity across studies was assessed by the Q and the <i>I</i>² statistic. In total, 27 observational studies were included. SEP was measured by insurance, income, poverty, employment, education, or an index on an area or individual level. SEP, regardless of indicator, was negatively associated with the steps in the treatment trajectory leading to initiation of ACT among patients with resected stage III CC. The meta-analyses showed that patients with low SEP had a significantly lower odds of receiving ACT and increased odds of delayed treatment start, whereas SEP had no impact on the choice of therapy: combination or single-agent therapy. SEP was associated with less initiation of and higher risk for delayed initiation of ACT. Our findings suggest there is a social disparity in receipt of ACT in patients with stage III CC.

社会经济地位（socioeconomic position, SEP）较低的结肠癌（colon cancer, CC）患者，其生存率显著劣于社会经济地位较高的患者。本研究针对III期结肠癌患者，探讨了不同社会经济地位指标与辅助化疗（adjuvant chemotherapy, ACT）启动前的治疗路径各环节之间的关联。本研究遵循MOOSE清单开展系统评价与荟萃分析，通过检索MEDLINE与EMBASE数据库筛选符合纳入标准的研究。针对各项独立的社会经济地位指标，本研究采用随机效应模型开展荟萃分析，并通过Q统计量与I²统计量评估各研究间的异质性。最终纳入27项观察性研究。社会经济地位的衡量维度包括保险状况、收入水平、贫困状态、就业情况、教育程度，或是区域/个体层面的综合指数。在接受根治性切除的III期结肠癌患者中，无论采用何种社会经济地位衡量指标，其社会经济地位与辅助化疗启动前的治疗路径各环节均呈负相关。荟萃分析结果显示，社会经济地位较低的患者接受辅助化疗的比值比显著更低，且治疗启动延迟的风险显著升高；而社会经济地位对治疗方案的选择（联合化疗或单药化疗）并无影响。社会经济地位较低与辅助化疗启动率更低、启动延迟风险更高显著相关。本研究结果提示，III期结肠癌患者在辅助化疗的获取方面存在社会经济地位相关的医疗公平差异。