The EUROCARE-6 Working Group researchers estimated that, in early 2020, an average of 5% of the European population had a recent or distant history of cancer. Most were female, older than 65 years, and living more than 5 years after a cancer diagnosis. Overall, 38% of all prevalent cases in Europe were living more than 10 years after a cancer diagnosis (44% female and 32% male). However, these proportions are lower than those estimated in the USA on 1 January 2020 (47% overall, 50% in women, and 44% in males) by using the same methodology and similar population-based data sources.
A lower long-term cancer prevalence in European populations is consistent with better prognosis generally reported for patients in the USA than in Europe according to Dr. Elena Demuru of the Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità in Rome, Italy, and colleagues, who reported the findings on 30 January 2024 in The Lancet Oncology.
The authors wrote in the background that cancer survivors are a relatively understudied population with diverse care needs depending on prognosis and time since diagnosis. The rapid increase in the number of cancer survivors in all ageing societies, combined with the cost of innovative therapies, poses a major challenge to the sustainability of public health systems. Detailed and comparable prevalence indicators are therefore also increasingly needed.
The study team searched MEDLINE on 18 April and 9 May 2023, focusing on documents published in English since 1 January 2002, when the EUROPREVAL project published the first complete cancer prevalence estimation in Europe using population-based cancer registry data. They prioritised evidence from population-based studies and identified a growing body of evidence on the healthcare needs of cancer survivors in Europe, but information on their actual number and characterisation is scattered and not comprehensive.
Systematic estimates of cancer prevalence by country are provided by the International Agency for Research on Cancer only for short-term follow-up within 5 years from diagnosis. Complete prevalence, including all people living longer than 5 years after a cancer diagnosis, is not routinely available in Europe. A main reason for this is that, unlike incidence or survival, complete prevalence cannot be measured from cancer registry data, but it must be estimated using specific methods to compensate for limited follow-up.
By analysing population-based cancer registry data from the EUROCARE-6 study, the researchers in this population-based study, used incidence and follow-up data up to 1 January 2013 from 61 cancer registries; complete and limited-duration prevalence by cancer type, sex, and age were estimated for 29 European countries and the 27 countries in the EU (EU27; represented by 22 member states that contributed registry data). They focused on 32 cancer types but only the first primary tumour was considered when estimating the prevalence. Prevalence measures were expressed in terms of absolute number of prevalent cases, crude prevalence proportion (reported as percentage or cases per 100 000 resident people), and age-standardised prevalence proportion based on the European Standard Population 2013. The study team made projections of cancer prevalence proportions up to 1 January 2020, using linear regression.
In 2020, 5.0% of the population were estimated to be alive after a cancer diagnosis in Europe. Cancer survivors were more frequently female than male. The five leading tumours in female survivors were breast cancer, colorectal cancer, corpus uterine cancer, skin melanoma, and thyroid cancer. Prostate cancer, colorectal cancer, urinary bladder cancer, skin melanoma, and kidney cancer were the most common tumours in male survivors.
The differences in prevalence between countries were large from 2 to 10 times depending on cancer type, in line with the demographic structure, incidence, and survival patterns. Between 2010 and 2020, the number of prevalent cases increased by 3.5% per year and 41% overall, partly due to an ageing population. In 2020, 14 850 thousand people were estimated to be alive more than 5 years after diagnosis and 9099 thousand people were estimated to be alive more than 10 years after diagnosis, representing an increasing proportion of the cancer survivor population.
The authors commented that the size of the population covered (61 cancer registries, 23 of which are national) strengthens the representativeness of the study. A unique data collection protocol and central quality control maximised the standardisation of individual data. The completeness index method was used to optimise the accuracy and international comparability of the estimates. Cancer survivors beyond 5 years are found to be a dominant and increasing proportion of the cancer survivor population.
They also commented that the large and growing burden of cancer on the European population confirms the need to strengthen cancer prevention measures, as envisaged in Europe's Beating Cancer Plan and related action plans. Furthermore, people living after a juvenile cancer have been shown to be an important component of long-term cancer survivors. The authors wrote that initiatives such as the survivorship passport or the legislation on the right to be forgotten should be pursued in all countries.
Complete information on cancer prevalence at country level is needed in Europe to develop evidence-based policies on cancer survivorship. This information should be systematically integrated into the European Cancer Information System. This study shows that an effective way to ensure accurate and comparable estimates of complete cancer prevalence at national level is to jointly analyse data from European registries. Future developments in this area should incorporate the analysis of cured cancer survivors and time to cure, to provide robust epidemiological evidence useful for responsibly optimising follow-up care guidelines and recommendations.
The study was funded by the European Commission.
Reference
De Angelis R, Demuru E, Baili P, et al. on behalf of the EUROCARE-6 Working Group. Complete cancer prevalence in Europe in 2020 by disease duration and country (EUROCARE-6): a population-based study. The Lancet Oncology; Published online 30 January 2024. DOI: https://doi.org/10.1016/S1470-2045(23)00646-0