The incidence of cancer continues to rise, both in high-income countries and, especially, in low-income and middle-income countries. Prevention is crucial, but implementation has been slow and incomplete, even in high-income countries. Prevention is a long-term strategy, and not all cancers can be prevented.1 To reduce cancer mortality, reduction of cancer incidence and improvement of cancer survival are both necessary.
Many patients will continue to be diagnosed with cancer every year for decades to come: an estimated 14 million patients a year worldwide around 2012,2 with a 50% projected increase to 21·6 million patients a year by 2030.3 Those patients will all need prompt diagnosis and optimal treatment to improve their survival. Monitoring the effectiveness of national and regional health systems in treating and caring for these patients becomes ever more crucial.
Research in context
Evidence before this study
In 2015, the second cycle of the CONCORD programme (CONCORD-2) established global surveillance of cancer survival as one of the key metrics of the effectiveness of health systems and to inform global policy on cancer control. This was done by analysis of individual records for 25·7 million patients diagnosed with one of ten common cancers during 1995–2009 and followed up to Dec 31, 2009. The data were provided by 279 population-based cancer registries in 67 countries. CONCORD-2 revealed wide differences in cancer survival trends that were attributed to differences in access to early diagnosis and optimal treatment.
Added value of this study
CONCORD-3 covers almost 1 billion people worldwide. It includes 15 common cancers in adults and three common cancers in children. Data quality has improved. The results are timely, published within 3 years of the end of follow-up. CONCORD-3 updates the worldwide surveillance of cancer survival to 2014. It includes data for over 37·5 million patients diagnosed with cancer during the 15-year period 2000–14. Data were provided by more than 320 population-based cancer registries in 71 countries and territories, including 27 countries of low or middle income; 47 countries provided data with 100% population coverage. The study now includes 18 cancers or groups of cancers: oesophagus, stomach, colon, rectum, liver, pancreas, lung, breast (women), cervix, ovary, prostate, and melanoma of the skin in adults, together with brain tumours, leukaemias, and lymphomas in both adults and children. These cancers represent 75% of all cancers diagnosed worldwide every year, in both low-income and high-income countries. The use of a similar study design and the same statistical methods as in CONCORD-2 enables the evaluation of survival trends for ten cancers over the 20-year period 1995–2014. For the first time, worldwide trends in survival are also available for cancers of the oesophagus, pancreas, and brain, and lymphomas and leukaemias.
Implications of all the available evidence
The CONCORD programme enables comparative evaluation of the effectiveness of health systems in providing cancer care. It also contributes to the evidence base for global policy on cancer control. CONCORD monitors progress towards the overarching goal of the 2013 World Cancer Declaration, to achieve “major reductions in premature deaths from cancer, and improvements in quality of life and cancer survival” by 2020. It provides evidence to support WHO policy following the Cancer Resolution passed by the World Health Assembly in 2017. The International Atomic Energy Agency's Programme for Action on Cancer Therapy used CONCORD-2 results in 2015 to launch its worldwide campaign to highlight the global divide in cancer survival, and to raise awareness of persistent inequalities in access to life-saving cancer services. The results were used in a Lancet Series on women's cancers in 2016. The US Centers for Disease Control and Prevention used the results in a 2017 supplement to the journal Cancer to inform cancer control policy designed to reduce racial differences in cancer survival.
CONCORD-3 can be expected to affect cancer control policy worldwide, especially in countries with low survival. The Organisation for Economic Co-operation and Development published a subset of CONCORD-3 results in 2017 as the official benchmark of cancer survival, among their indicators of the quality of health care in 48 countries worldwide. The survival estimates will also form part of the Lancet Oncology Commission on childhood cancer in 2018. Future research will include examination of the impact on international differences in cancer survival of stage at diagnosis, compliance with treatment guidelines, and the quality of health care.
In 2016, the WHO Executive Board recommended strengthening health systems to ensure early diagnosis and accessible, affordable, high-quality care for all patients with cancer.3 The World Health Assembly followed up with a resolution on cancer control in May, 2017. It included recommendations that national cancer control strategies should aim to reduce late presentation and ensure appropriate treatment and care for potentially curable malignancies such as acute leukaemia in children “to increase survival, reduce mortality and improve quality of life”.4
President Tabaré Vázquez of Uruguay and WHO Director-General Tedros Ghebreyesus have called for all countries “to provide universal health coverage, thereby ensuring all people can access needed preventive and curative health-care services, without falling into poverty”.5 Their call relates to all non-communicable diseases, including cancer. Population-based cancer survival is one metric that can help evaluate whether all people have access to effective treatment services.
In 2015, the second cycle of the CONCORD programme (CONCORD-2) established global surveillance of cancer survival for the first time,6 with publication of trends in survival over the 15-year period 1995–2009 among patients diagnosed with cancer in 67 countries, home to two thirds (4·8 billion) of the world's population. In 40 countries, the data had 100% national population coverage. CONCORD-2 incorporated centralised quality control and analysis of individual data for 25 676 887 patients diagnosed with one of the ten common cancers that represented 63% of the global cancer burden in 2009. The 279 population-based registries covered a combined total population of 896 million people.
The US National Cancer Institute, in an invited commentary7 for The Lancet, noted that the global analyses of cancer survival in CONCORD-2 provided insights from countries with successful cancer control initiatives that could be applied in other regions, and that the availability of better data “provides a clearer picture of the effect of cancer control programmes on the ultimate goal of improving survival and reducing the effect of cancer on the social and economic development of countries”.
The US Centers for Disease Control and Prevention described CONCORD-2 as the start of global surveillance of cancer survival,8 with survival estimates “that can be compared so scientists can begin to determine why survival differs among countries. This could lead to improvements in cancer control programs.” The results from CONCORD-2 influenced national cancer control strategy in the UK in July, 2015.9, 10 In September, 2015, the International Atomic Energy Agency's Programme for Action on Cancer Therapy used the results to launch a worldwide campaign11 to highlight the global divide in cancer survival, and to raise awareness of persistent inequalities in access to life-saving cancer services.12 Further analyses of survival trends and disparities by race and stage at diagnosis in 37 US states have been included in a supplement to Cancer,13, 14 designed to improve cancer control in the USA.
CONCORD-3 updates worldwide surveillance of cancer survival trends to include patients diagnosed up to 2014, with follow-up to Dec 31, 2014. In countries that were already involved, more registries are participating, and eight more countries have joined the programme. Follow-up for patients diagnosed during 2000–09 with one of the ten cancers included in CONCORD-2 has been updated. CONCORD-3 includes data for patients diagnosed during 2000–14 with one of 18 malignancies that represent 75% of the global cancer burden (table 1). In addition to information on stage at diagnosis, we have collected data on tumour grade and the first course of treatment. Findings are published within 3 years of the end of follow-up.