PARIS, July 16, 2008 (AFP) - The United States holds the best overall record for surviving cancer, despite a large disparity between American blacks and whites, while Algeria has the worst, according to a study of 31 countries published on Thursday.

The paper, appearing online in the journal The Lancet Oncology, found wide ranges in the chances of surviving breast, colo-rectal or prostate cancer in North America, Europe, Japan, Brazil, Australia and Cuba.

The analysis is based on data from 1.9 million adults diagnosed with early-stage cancer between 1990 and 1994, and whose outcome was followed up five years later.

Survival at the five-year benchmark was highest in the United States for breast and prostate cancer, followed by Canada and Austria respectively.

For colorectal cancer among women, France was top, followed by the United States; and for colorectal cancer in men, the leader was Japan, with the United States in second place.

At the bottom in all three categories was Algeria, whose data came from the province of Setif, in the northeast of the country, covering four percent of the population.

For example, the chances of being alive in Setif five years after diagnosis of breast cancer were only 38.8 percent, compared with 83.9 percent in the United States. The comparative survival for rectal cancer among women in Setif was only 18.2 percent, compared with 63.9 percent in France.

'Survival in Setif was similar to or even lower than survival in blacks diagnosed during 1993-1997 in Harare, the Zimbabwean capital, where the very low survival rate was attributed to inadequate access to facilities for early diagnosis, clinical investigation and treatment,' the paper said.

European survival rates were higher in western Europe than eastern Europe, a region hit by the post-Communist economic collapse in the 1990s and where there has been an improvement in cancer treatment in recent years, lead author Michel Coleman, a professor at the London School of Hygiene and Tropical Medicine, told AFP.

Coleman also noted a large disparity among US states and between American whites and blacks.

Among the 16 states and metropolitan areas covered in the study, there was typically a gap of between six and seven percentage points in survivability according to the location.

Ranked persistently at the bottom was New York City, which had the lowest survival rates of all cancers studied, except rectal cancer in women.

And white people had a 14-percent higher chance of surviving breast cancer, compared with blacks, the paper found. This gap narrowed but remained significant in the other cancer categories, reaching seven percent in prostate cancer.

Coleman said a range of well-known problems were likely to explain this black-white gap.

They included a lack of health insurance, or inadequate health insurance, among US blacks; poor awareness of the need to respond to the early signs of cancer; and poor access to medical care that would identify a tumour in time and treat it effectively.

Cuba was included in the study and, in terms of raw statistics, came top in two categories and second in a third category.

Coleman explained, though, that the Cuban data had to be largely discounted because of a question mark about death-certificate figures.