The World Health Organization’s International Agency for Research on Cancer (IARC) released a new publication of cancer survival data from 27 population-based cancer registries in 14 countries called “Cancer Survival in Africa, Asia, the Caribbean and Central America.” The publication is a follow-up to the 1999 volume entitled “Cancer Survival in Developing Countries”. The new publication, which is also available in electronic form on the internet, includes survival data for the years 1990-2000 and represents data from three times as many cancer registries as in the earlier volume, and a vast increase in the number of cancer sites and patients.
Cancer survival rates are important benchmarks to measure progress against cancer, as high survival rates for a given cancer result from the availability, affordability and accessibility of effective detection, treatment and follow-up care services. Reliable information on cancer survival rates is invaluable to health professionals and policymakers, as well as to patients, their families, and the general public.
These cancer survival rates are often derived from selected hospitals or clinical trials, reflecting the experience of selected groups of patients. However, estimates of survival based on all cancer patients in a given geographical region, called population-based cancer survival estimates, indicate the overall efficiency of that region’s health services in providing affordable, accessible and effective early detection, treatment and follow-up care.
Such survival rates are obtained by careful follow-up of patients registered in population-based cancer registries, as they systematically collect information on all cancer patients in a defined geographical region and provide valuable information on current and evolving patterns of the cancer burden in terms of new cases and cancer deaths. Although population-based cancer survival information is readily available from developed countries in Europe, North America and Australia, it is relatively rare from low- and medium-resource countries in Africa, Asia and Central and South America.
“Cancer Survival in Africa, Asia, the Caribbean and Central America” reveals striking inequities in cancer survival between and within countries, reflecting a wide range in cancer health services. For instance, 5-year survival for breast cancer ranged from 12.5% in the Gambia to 81% in Busan in the Republic of Korea. Countries with highly developed health services, such as Singapore and the Republic of Korea, where early detection and adequate treatment are available, had significantly higher survival for cancers such as breast, uterine cervix, head and neck, large bowel, and lymphoma. Survival rates of early-stage breast cancers in India, the Philippines, Thailand, and Costa Rica were similar to those of moderately advanced breast cancers in countries with more developed health services, such as Singapore and Turkey; 5-year survival of moderately advanced breast cancers in India, the Philippines, Thailand and Costa Rica was 47%, versus 75% in Singapore and Turkey. In India, 5-year survival for early-stage breast cancer ranged from 41% to 78% by region, indicating wide variation in health services delivery; it varied little by region in Thailand, indicating more uniform development of health services. Another striking finding is that 5-year survival did not exceed 22% for any cancer site in the Gambia, or 13% for any cancer site except breast (46%) in Uganda.
These marked differences in survival outcomes show that the development of health services and their efficiency in providing early diagnosis, treatment and follow-up care have profound influence on cancer survival. These results call for urgent investment by governments in low- and medium-resource countries to improve awareness, early detection programmes, and health services infrastructure and accessibility.