Suzuki-Chiba Hiroe, Miyawaki Atsushi, Hakozaki Taiki, Aso Shotaro, Matsui Hiroki, Yasunaga Hideo
Department of Health Communication, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Department of Health Services Research, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Cancer Med. 2025 Jul;14(13):e71038. doi: 10.1002/cam4.71038.
Recent advances in immunotherapy have improved the survival of patients with non-small cell lung cancer (NSCLC). However, data on the association between patient socioeconomic status (SES) and the use of immunotherapy remain scarce. We examined the association between area-level SES and immunotherapy use in patients with stage IV NSCLC in Japan.
Data from a national inpatient database were used for this analysis. Patients aged ≥ 18 years, hospitalized for stage IV NSCLC, and treated with immunotherapy alone, immunotherapy combined with platinum-based chemotherapy, and platinum-based chemotherapy alone as first-line pharmacotherapy from April 2016 to March 2022 were analyzed. Area-level SES was measured using the area deprivation index and categorized into quartiles. The primary outcome was the use of immunotherapy as a first-line treatment. A multivariate linear regression model was used, adjusted for patient characteristics, years, and hospital fixed effects.
A total of 47,291 eligible patients from 843 hospitals, with 22,205 (47%) receiving immunotherapy. Adjusted analyses showed that patients in the most disadvantaged area were less likely to receive immunotherapy compared with those in the least disadvantaged area (adjusted difference, -2.0 percentage points [pp]; 95% confidence interval, -3.6 to -0.5 pp; p = 0.01). Although not significant, this trend persisted when stratified by urban and cancer-designated hospitals. However, this difference was no longer significant after adjusting for hospital fixed effects.
In Japan, with universal public health insurance with low out-of-pocket costs, living in a socioeconomically disadvantaged area is associated with lower rates of immunotherapy use among patients with stage IV NSCLC. These disparities disappeared within the same hospitals using hospital fixed effects; however, such disparities tended to persist in urban, non-academic, and cancer-designated hospitals. These findings suggest the need for interventions to address the structural barriers, including those within the hospitals, to optimize NSCLC treatment and reduce health disparities.
免疫疗法的最新进展提高了非小细胞肺癌（NSCLC）患者的生存率。然而，关于患者社会经济地位（SES）与免疫疗法使用之间关联的数据仍然稀少。我们研究了日本IV期NSCLC患者的地区层面SES与免疫疗法使用之间的关联。
本分析使用了全国住院患者数据库的数据。分析了2016年4月至2022年3月期间年龄≥18岁、因IV期NSCLC住院并接受单独免疫疗法、免疫疗法联合铂类化疗以及单独铂类化疗作为一线药物治疗的患者。使用地区剥夺指数衡量地区层面的SES，并将其分为四分位数。主要结局是使用免疫疗法作为一线治疗。使用多变量线性回归模型，并对患者特征、年份和医院固定效应进行了调整。
来自843家医院的47291名符合条件的患者中，有22205名（47%）接受了免疫疗法。调整分析显示，与最不弱势地区的患者相比，最弱势地区的患者接受免疫疗法的可能性较小（调整差异为-2.0个百分点[pp]；95%置信区间为-3.6至-0.5 pp；p = 0.01）。尽管不显著，但按城市和癌症指定医院分层时，这一趋势仍然存在。然而，在调整医院固定效应后，这种差异不再显著。
在日本，由于公共医疗保险普及且自付费用较低，生活在社会经济弱势地区与IV期NSCLC患者免疫疗法使用率较低有关。使用医院固定效应后，这些差异在同一家医院内消失；然而，这种差异在城市、非学术和癌症指定医院中往往仍然存在。这些发现表明需要采取干预措施来消除包括医院内部障碍在内的结构性障碍，以优化NSCLC治疗并减少健康差距。
