Cancer survival varies widely between countries according to a worldwide study published online today in Lancet Oncology.* More than 100 investigators contributed to the study.
And while the USA has the highest 5-year survival rate for prostate cancer than any of the 31 countries studied, cancer survival in black men and women is systematically and substantially lower than in white men and women.
Until now, direct comparisons of cancer patient survival between rich and poor countries have not generally been available. The CONCORD study is, to the authors' knowledge, the first worldwide analysis of cancer survival, with standard quality-control procedures and identical analytic methods for all datasets. It provides directly comparable data on 1.9 million adult cancer patients (aged between 15 and 99) from 101 cancer registries in 31 countries on 5 continents. The study covers cancers of the breast (women), colon, rectum and prostate, which comprise a majority of all newly diagnosed cancers in adults. The study includes analyses of cancer survival in 16 states and 6 metropolitan areas in the USA, covering 42% of the population four times as many as in previous studies.
Five-year relative survival for breast cancer (women) ranged from 80% or higher in North America, Sweden, Japan, Finland and Australia to less than 60% in Brazil and Slovakia, and below 40% in Algeria. Survival for white women in the USA (84.7%) was 14% higher than for black women (70.9%).
For colorectal cancer, five-year survival was higher in North America, Japan, Australia and some western European countries and lower in Algeria, Brazil and in eastern European countries. Survival for white patients in the USA was 10% higher than for black patients (60% compared with 50%).
For prostate cancer, 5-year survival was higher in the USA (92%) than in all 30 of the other participating countries. However, there was a 7% difference in survival between black and white men (92% compared with 85.8%).
Michel P Coleman, Professor of Epidemiology and Vital Statistics at the London School of Hygiene & Tropical Medicine, and lead author of the study, comments: 'The differences in cancer survival between countries and between black and white men and women in the USA are large and consistent across geographic areas. Most of the wide variation in survival is likely to be due to differences in access to diagnostic and treatment services, and factors such as tumour biology, state at diagnosis or compliance with treatment may also be significant.
'Population-based cancer registries are increasingly important in monitoring cancer control efforts, and in evaluating cancer survival. We hope that the information provided here will facilitate better comparison between rich and poor countries, and eventually enable joint evaluation of international trends in cancer incidence, survival and mortality'.