National health system characteristics, breast cancer stage at diagnosis, and breast cancer mortality: a population-based analysis
Menée à partir des données GLOBOCAN 2020 et d'une revue de la littérature publiée entre 2010 et 2020, cette étude analyse l'association entre des caractéristiques du système national de santé de 148 pays, le stade de la maladie au diagnostic et la mortalité par cancer du sein
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 thisstudy, we aimed to characterise the associations between national health system characteristics and breast cancer age-standardised mortality rate, and the degree of breast cancerdownstaging 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 witha broad panel of standardised national health system data as reported in the WHO CancerCountry Profiles 2020. These health system characteristics include health expenditure,the Universal Health Coverage Service Coverage Index (UHC Index), dedicated fundingfor early detection programmes, breast cancer early detection guidelines, referralsystems, cancer plans, number of dedicated public and private cancer centres per 10 000 patients with cancer, and pathology services. We tested for differences between continuousvariables using the non-parametric Kruskal-Wallis test, and for categorical variablesusing the Pearson
χ2 test. Simple and multiple linear regression analyses were fitted to identify associationsbetween health system characteristics and age-standardised breast cancer mortalityrates. Data on TNM stage at diagnosis were obtained from national or subnational cancerregistries, 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. Thethreshold 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 significantlyhigher 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 detectionprogrammes (p=0·0020), breast cancer early detection guidelines (p<0·0001), breastcancer referral systems (p=0·0030), national cancer plans (p=0·014), cervical cancerearly detection programmes (p=0·0010), number of dedicated public (p<0·0001) and private(p=0·027) cancer centres per 10 000 patients with cancer, and pathology services (p<0·0001).In adjusted multivariable regression analyses in 141 countries, two health systemcharacteristics were significantly associated with lower age-standardised mortalityrates: higher UHC Index levels (
β=
–0·12, 95% CI −0·16 to −0·08) and increasing numbersof public cancer centres (
β=
–0·23, −0·36 to −0·10). These findings indicate that eachunit increase in the UHC Index was associated with a 0·12-unit decline in age-standardisedmortality rates, and each additional public cancer centre per 10 000 patients withcancer 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 achievedsustained mean reductions in age-standardised mortality rate of 2% or more per yearfor at least 3 consecutive years since 1990 had at least 60% of patients with invasivebreast cancer presenting as stage I or II disease. Some countries achieved this reductionwithout most women having access to population-based mammographic screening.
Interpretation : Countries with low breast cancer mortality rates are characterised by increased levelsof coverage of essential health services and higher numbers of public cancer centres.Among countries achieving sustained mortality reductions, the majority of breast cancersare diagnosed at an early stage, reinforcing the value of clinical early diagnosisprogrammes for improving breast cancer outcomes.
The Lancet Oncology , résumé, 2020