US cancer survival rates remain among highest in world
Five-year survival for the most common 18 cancers remained highest globally for the United States, Canada, Australia and New Zealand, followed by Finland, Iceland, Norway and Sweden, according to data through 2014 from CONCORD-3.
Survival rates in Denmark also appeared to be narrowing the gap with other Nordic countries.
Claudia Allemani, PhD, associate professor in cancer epidemiology at London School of Hygiene and Tropical Medicine, and colleagues of the CONCORD program established surveillance of cancer survival as a metric to assess the efficacy of worldwide health systems to better inform a global policy on cancer control in 2015.
“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, with a 50% projected increase to 21.6 million patients a year by 2030,” Allemani and colleagues wrote. “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.”
To update global cancer survival rates from patients diagnosed in 2000 to 2009 reported in CONCORD-2, researchers evaluated data from 37.5 million patients diagnosed through 2014 using 322 population-based cancer registries from 71 countries.
Researchers evaluated 18 malignancies that represented 75% of cancer diagnoses: cancers of the esophagus, stomach, colon, rectum, liver, pancreas, lung, female breast, cervix, ovary and prostate; adult melanoma; brain tumors; leukemia; and lymphoma in children and adults.
Survival trends generally increased across countries, even for lethal cancers. Researchers observed increases up to 5 percentage points for liver, pancreatic and lung cancers.
For women diagnosed with breast cancer between 2010 and 2014, 5-year survival rates reached 89.5% in Australia and 90.2% in the United States, but generally varied worldwide and remained low in some countries, such as at 66.1% in India.
The highest levels of 5-year survival for gastrointestinal cancers diagnosed from 2010 to 2014 occurred in southeast Asia. In South Korea, survival rates reached 68.9% for stomach cancer, 71.8% for colon cancer and 71.1% for rectum cancer. Esophageal cancer survival rates were 36% in Japan, and liver cancer rates reached 27.9% in Taiwan.
However, southeast Asia had generally lower survival rates for melanoma (South Korea, 59.9%; Taiwan, 52.1%; China, 49.6%), lymphoid malignancies (South Korea, 52.5%; Taiwan, 50.5%; China, 38.3%) and myeloid malignancies (South Korea, 45.9%; Taiwan, 33.4%; China, 24.8%).
In comparison, in the United States 5-year survival rates for gastrointestinal cancers were 33.1% for stomach cancer, 64.9% for colon cancer, 64.1% for rectum cancer, 20% for esophageal cancer and 17.4% for liver cancer. Researchers observed 5-year U.S. survival rates of 90.8% for melanoma, 46.7% for lymphoid malignancies and 68.1% for myeloid malignancies.
Five-year survival for acute lymphoblastic leukemia among children diagnosed from 2010 to 2014 ranged from 49.8% in Ecuador to 89.5% in the United States and 95.2% in Finland. Brain tumor survival rates among children ranged from 28.9% in Brazil to 78.2% in the United States and nearly 80% in Sweden and Denmark.
These results show how population-based cancer registries can serve as key policy tools to evaluate the impact of cancer prevention strategies and the effectiveness of health systems, the researchers wrote.
“All registries, especially those in low-income and middle-income countries, need to be given adequate resources to register all patients with cancer in a timely fashion, the right to access up-to-date national and regional death records to establish their vital status, and the legislative stability to operate efficiently over the long term,” they wrote.
These “stark inequalities in outcomes” observed across countries highlight the consequences of insufficient funding and governance failures, Richard Sullivan, MD, PhD, professor of cancer policy and global health at Kings College London and founding director of Kings Institute of Cancer Policy, wrote in a related editorial.
“High-income countries spend substantial amounts on cancer control and research, yet the resources dedicated to enhancing capability and capacity in partner low-income and middle-income countries remain poor,” he wrote. “Likewise, development assistance for health provides little direct help to build cancer control systems. Both of these things have to change if the gap in outcomes is to be narrowed. Oncoplutocracy, in which cancer progress only benefits wealthy countries and patients, needs to stop.” – by Alexandra Todak
Disclosures: The study authors and Sullivan report no relevant financial disclosures.