单项选择题

U.S. Blacks Hard Hit by Cancer
Death rates for cancer are falling for all Americans. But black Americans are still more likely to die of cancer than whites, the American Cancer Society said Monday.
In a special report on cancer and blacks, the organization said blacks are usually diagnosed with cancer later than whites, and they are more likely to die of the disease.
This could be because of unequal (不平等的) access to medical Care. Because blacks are more likely to have other diseases as well, and perhaps because of differences in the biology (生物学) of the cancer itself, the report added.
"In general, black Americans have less hope of surviving five years after diagnosis than whites for all cancer sites and all stages of diagnosis." the report said.
"In describing cancer statistics for black Americans, this report recognizes that many of the differences associated with race may be caused by unfair social and economic differences and unequal access to medical care."
The cancer society said blacks should be encouraged to get check-ups (体格检查) earlier, when cancer is more treatable. And it said more research is needed to see if biological differences play a role.
"The new statistics emphasize the continuing importance of wiping out these unfair social differences through public policy and education efforts," the organization said in a statement.
But it also noted a drop in cancer death rates.
"Cancer death rates in both sexes for all sites combined have dropped greatly among black Americans since 1992, as have incidence rates (发生率)," said the report. Since 1992, cancer death rates among black Americans ______.