Cancer survival is generally increasing, even for some of the more deadly cancers such as liver and lung, according to the largest and most up-to-date study of population-based survival trends (2000–2014), covering countries that are home to more than two-thirds of the world’s population. But survival trends vary widely – example, for women diagnosed with breast cancer in the USA and Australia between 2010 and 2014, 5-year survival is 90%, compared to 66% for women diagnosed in India.
The CONCORD-3 study, published in The Lancet , analysed individual patient records from 322 cancer registries in 71 countries and territories to compare 5-year survival from diagnosis for more than 37.5 million adults (aged 15–99 years) and children (0–14 years) with one of 18 common cancers . These cancers represent three-quarters of all cancers diagnosed worldwide every year between 2000 and 2014. For the 10 cancers already included in the CONCORD-2 study, the researchers were able to examine trends over the 20-year period 1995¬–2014, and there are wide and persistent disparities between countries, particularly for some childhood cancers. For example, while brain tumour survival in children has improved in many countries, 5-year survival is twice as high in Denmark and Sweden (around 80%) as in Mexico and Brazil (less than 40%) for children diagnosed as recently as 2014. This is likely to reflect the availability and quality of diagnostic and treatment services.
India has an estimated one million new cases of cancer every year. In 2012 there were about 600000-700000 deaths in India because of cancer, many of them tobacco related or because of infections and other avoidable causes. Studies show that social factors, especially inequalities, are major determinants of India’s cancer burden, with poorer people more likely to die from cancer before the age of 70 years than those who are more affluent.”
The Lancet study found that five-year net survival from colon cancer was 40–49% in Argentina, Bulgaria, Chile, Colombia, Latvia, and Russia, and it was less than 40% in India, Indonesia, and Mongolia. Survival from rectal cancer was very low in India (29%). Lead author Dr Claudia Allemani from the Cancer Survival Group at the London School of Hygiene & Tropical Medicine explained, “Continuous monitoring of global trends in cancer survival is crucial to assess the overall effectiveness of health systems world-wide, and to help policy-makers plan better strategies for cancer control. But, inadequate or unreliable data prevent governments from understanding the true nature and magnitude of the public health problems created by the growing cancer burden. This leaves governments poorly equipped to develop national cancer plans that will translate into real improvements in survival for patients.”
She added, “Governments must recognise cancer registries as efficient public health instruments that produce a continuous stream of valuable information on both the impact of cancer prevention strategies and the effectiveness of health systems, and at very low cost. In Europe, the cost of registering one case is less than the cost of a chest x-ray, and without this kind of information, health ministries are flying blind on cancer control.” [5]
In the UK, overall cancer survival is improving, with several cancers showing substantial increases in 5-year survival between 2000 and 2014, including breast (80% to 86%), prostate (82% to 89%), rectum (55% to 63%) and colon (52% to 60%)—reflecting better cancer management. However, adults with cancer continue to have lower 5-year survival than in other comparable countries for several common cancers, including myeloid malignancies (such as acute myeloid leukaemia) and adult brain cancer.
While liver and lung cancers remain rapidly lethal in high- and low-income countries alike, the past two decades have seen some important progress in 5-year survival in several nations. Liver cancer survival increased by more than 10% in Korea (11% to 27%), Sweden (5% to 17%), Portugal (8% to 19%), and Norway (6% to 19%). Similarly, lung cancer survival increased by 5–10% in 21 countries including the UK (7% to 13%) between 1995 and 2014, with most progress seen in China (8% to 20%), Japan (23% to 33%), and Korea (10% to 25%).
But not all major cancers have seen such improvements. Even in 2014, pancreatic cancer remained highly lethal in all countries, with 5-year survival typically less than 15%.
The analysis highlights that survival differences in childhood brain cancer are particularly wide, ranging from less than 40% during 2010-2014 in Brazil and Mexico to around 80% in Sweden, Denmark, and Slovakia. Despite increases in most countries since the mid-1990s, 5-year survival for children diagnosed with the most common type of childhood cancer (acute lymphoblastic leukaemia; ALL) also varies substantially worldwide, indicating major deficiencies in the diagnosis and treatment of a disease that is generally considered as curable. 5-year survival is higher than 90% in several countries, including Canada, the USA and nine European countries (e.g., Finland, the UK, and Denmark), but it remains below 60% in China, Mexico, and Ecuador.
Professor Coleman explains, “Despite improvements in awareness, services, and treatments, cancer still kills more than 100,000 children every year worldwide. If we are to ensure that more children survive cancer for longer, we need reliable data on the cost and effectiveness of health services in all countries, to compare the impact of strategies in managing childhood cancer.” [5]
Writing in a linked Comment, Professor Richard Sullivan from the King’s Health Partners Comprehensive Cancer Centre in London says, “Despite more than 20 years of advocacy for national and international funding to support the establishment of fully functional cancer registries, both domestic and global political support and funding remain woeful. Considering the billions of dollars poured into research each year, the fact that the one universal need for all countries—cancer intelligence from national and regional registries—cannot be properly supported reflects both political myopia and distorted priorities… National and regional governments must recognise that population-based cancer registries are key policy tools, both to monitor the impact of cancer prevention strategies, and to evaluate the effectiveness of the health system for all patients diagnosed with cancer.”
