乳腺癌死亡率下降国家有两大特征
1990年代以来，不同国家之间、同一国家不同地区之间，癌症患者生存结局的差距日益显著，一些地区已经实现了癌症发病率和死亡率的下降，而另一些地区则大大落后。例如，一些国家的乳腺癌患者年龄标准化死亡率每年下降2%～4%，但是其他国家的乳腺癌患者尚未实现该生存结局。
2021年10月12日，英国《柳叶刀》肿瘤学分册在线发表美国西雅图华盛顿大学弗雷德·哈钦森癌症研究中心、世界卫生组织国际癌症研究机构、意大利米兰大学欧洲肿瘤研究所的研究报告，分析了国家卫生系统特征对乳腺癌诊断时分期和乳腺癌患者年龄标准化死亡率的影响。
该人群研究将全球癌症（GLOBOCAN）2020年统计报告各国≤69岁女性年龄标准化死亡率与世界卫生组织《各国癌症概况》2020年各国标准化卫生系统数据进行关联。这些卫生系统特征包括卫生支出、全民卫生服务覆盖指数、早期检测项目专项资金、乳腺癌早期检测指南、转诊系统、癌症计划、每万例患者拥有的癌症中心和病理检测机构数量。通过单因素和多因素线性回归，分析卫生系统特征对乳腺癌患者年龄标准化死亡率的影响。乳腺癌诊断时分期数据来自各国或各地区的癌症登记中心以及2010～2020年PubMed文献检索。利用世界卫生组织癌症死亡率数据库对1950～2016年乳腺癌患者死亡率变化趋势进行分析。
结果，148个国家提供了完整的卫生系统数据，根据未校正分析，高收入国家与低收入国家相比，显著影响年龄标准化死亡率的卫生系统特征包括：
卫生支出（P=0.0002）
全民卫生服务覆盖指数（P<0.0001）
早期检测项目专项资金（P=0.0020）
乳腺癌早期检测指南（P<0.0001）
乳腺癌转诊系统（P=0.0030）
国家癌症计划（P=0.014）
宫颈癌早期检测项目（P=0.0010）
每万例癌症患者拥有的公立癌症中心数量（P<0.0001）
每万例癌症患者拥有的私立癌症中心数量（P=0.027）
每万例癌症患者拥有的病理检测机构数量（P<0.0001）
对其中141个国家进行多因素线性回归校正分析，高收入国家与低收入国家相比，显著影响年龄标准化死亡率的卫生系统特征仅剩两个：
全民卫生服务覆盖指数每提高1，年龄标准化死亡率可下降0.12（β=-0.12，95%置信区间：-0.16～-0.08）
每万例癌症患者拥有的公立癌症中心数量每增加1，年龄标准化死亡率可下降0.23（β=-0.23，95%置信区间：-0.36～-0.10）
35个国家提供了乳腺癌分期数据，1990年以来至少连续3年实现年龄标准化死亡率持续平均每年下降≥2%的全部20个国家，至少六成患者的乳腺浸润癌为I期或II期。
一些国家在大多数女性无法获得人群乳腺钼靶筛查的情况下，仍然实现了年龄标准化死亡率下降。
因此，该研究结果表明，乳腺癌患者死亡率下降的国家卫生系统特征为基本卫生服务覆盖水平提高和公立癌症中心数量增加。在实现死亡率持续下降的国家中，大多数乳腺癌于早期被诊断，这提高了临床早期诊断计划对改善乳腺癌结局的价值。
对此，加拿大卡尔加里大学卡明医学院发表同期评论：解决中低收入国家的乳腺癌患者死亡率——工欲善其事，必先利其器。
Lancet Oncol. 2021 Oct 12. Online ahead of print.
National health system characteristics, breast cancer stage at diagnosis, and breast cancer mortality: a population-based analysis.
Catherine Duggan, Dario Trapani, André M Ilbawi, Elena Fidarova, Mathieu Laversanne, Giuseppe Curigliano, Freddie Bray, Prof Benjamin O Anderson.
University of Washington, Seattle, WA, USA; Fred Hutchinson Cancer Research Center, Seattle, WA, USA; World Health Organization, Geneva, Switzerland; International Agency for Research on Cancer, Lyon, France; University of Milan, Milan, Italy; European Institute of Oncology, IRCCS, Milan, Italy.
BACKGROUND: In some countries, breast cancer age-standardised mortality rates have decreased by 2-4% per year since the 1990s, but others have yet to achieve this outcome. In this study, we aimed to characterise the associations between national health system characteristics and breast cancer age-standardised mortality rate, and the degree of breast cancer downstaging correlating with national age-standardised mortality rate reductions.
METHODS: In this population-based study, national age-standardised mortality rate estimates for women aged 69 years or younger obtained from GLOBOCAN 2020 were correlated with a broad panel of standardised national health system data as reported in the WHO Cancer Country Profiles 2020. These health system characteristics include health expenditure, the Universal Health Coverage Service Coverage Index (UHC Index), dedicated funding for early detection programmes, breast cancer early detection guidelines, referral systems, cancer plans, number of dedicated public and private cancer centres per 10000 patients with cancer, and pathology services. We tested for differences between continuous variables using the non-parametric Kruskal-Wallis test, and for categorical variables using the Pearson χ2 test. Simple and multiple linear regression analyses were fitted to identify associations between health system characteristics and age-standardised breast cancer mortality rates. Data on TNM stage at diagnosis were obtained from national or subnational cancer registries, supplemented by a literature review of PubMed from 2010 to 2020. Mortality trends from 1950 to 2016 were assessed using the WHO Cancer Mortality Database. The threshold for significance was set at a p value of 0.05 or less.
FINDINGS: 148 countries had complete health system data. The following variables were significantly higher in high-income countries than in low-income countries in unadjusted analyses: health expenditure (p=0.0002), UHC Index (p<0.0001), dedicated funding for early detection programmes (p=0.0020), breast cancer early detection guidelines (p<0.0001), breast cancer referral systems (p=0.0030), national cancer plans (p=0.014), cervical cancer early detection programmes (p=0.0010), number of dedicated public (p<0.0001) and private (p=0.027) cancer centres per 10000 patients with cancer, and pathology services (p<0.0001). In adjusted multivariable regression analyses in 141 countries, two health system characteristics were significantly associated with lower age-standardised mortality rates: higher UHC Index levels (β=-0.12, 95% CI -0.16 to -0.08) and increasing numbers of public cancer centres (β=-0.23, -0.36 to -0.10). These findings indicate that each unit increase in the UHC Index was associated with a 0.12-unit decline in age-standardised mortality rates, and each additional public cancer centre per 10000 patients with cancer was associated with a 0.23-unit decline in age-standardised mortality rate. Among 35 countries with available breast cancer TNM staging data, all 20 that achieved sustained mean reductions in age-standardised mortality rate of 2% or more per year for at least 3 consecutive years since 1990 had at least 60% of patients with invasive breast cancer presenting as stage I or II disease. Some countries achieved this reduction without most women having access to population-based mammographic screening.
INTERPRETATION: Countries with low breast cancer mortality rates are characterised by increased levels of coverage of essential health services and higher numbers of public cancer centres. Among countries achieving sustained mortality reductions, the majority of breast cancers are diagnosed at an early stage, reinforcing the value of clinical early diagnosis programmes for improving breast cancer outcomes.
DOI: 10.1016/S1470-2045(21)00462-9
Lancet Oncol. 2021 Oct 12. Online ahead of print.
Addressing breast cancer mortality in low-income and middle-income countries: if you can't measure it, it doesn't exist.
Emily Heer.
Cumming School of Medicine, University of Calgary, AB, Canada.
Disparities in cancer outcomes within and between countries have become increasingly more visible in the past two decades; some regions have achieved reductions both cancer incidence and mortality, whereas others are falling dramatically behind. In The Lancet Oncology, Catherine Duggan and colleagues report that 20 countries have achieved sustained mean reductions in breast cancer mortality of at least 2% for 3 consecutive years since 1990, all of which are either high-income or upper-middle-income countries. All 20 of these countries with sustained mortality reductions had at least 60% of patients with breast cancer diagnosed at early stages (stage I or II) of disease. In the multivariable analysis, the Universal Health Care Service Coverage Index score and number of public cancer centres per 10000 patients with cancer were significantly and independently negatively associated with age-standardised mortality rates (β=-0.12, 95% CI -0.16 to -0.08, and β=-0.23, -0.36 to -0.10, respectively). These results provide useful additional information on which future research might be based.
DOI: 10.1016/S1470-2045(21)00519-2