woman_on_exercise_bike_web.jpgCHICAGO (AP) — Provocative new research might help explain why black women are so much more likely than whites to develop and die from cervical cancer: They seem to have more trouble clearing HPV, the virus that causes the disease.

Doctors have long thought that less access to screening and follow-up health care were the reasons black women in the U.S. are 40 percent more likely to develop cervical cancer and twice as likely to die from it. The new study involving young college women suggests there might be a biological explanation for the racial disparity, too.

Certain strains of HPV, the human papillomavirus, cause cervical cancer, but brief infections are very common in young women. They usually go away on their own within a year or so and only pose a cancer risk when they last long-term.

Researchers at the University of South Carolina in Columbia studied 326 white and 113 black students taking part in a wider federal health study. All were given Pap tests — lab exams of cells scraped from the cervix — and HPV tests every six months throughout their years in school.

Although the groups were similar in how many new HPV infections were detected and risk factors such as how many sex partners they had, doctors saw striking differences in how long their infections lasted.

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At any checkup, blacks were 1.5 times more likely to test positive for infection with one of the HPV strains that raise cancer risk, said study leader Kim Creek.

“The African-American women weren't clearing the virus as fast. They were actually holding onto it about six months longer,” for 18 months versus 12 months for whites, he said.

Ten percent of blacks had abnormal Pap tests versus 6 percent of whites.

Two years after initial infections were found, 56 percent of black women were still infected but only 24 percent of whites remained infected.

The government's National Institute on Minority Health and Health Disparities sponsored the study. Creek is a paid speaker for Merck & Co., one of the makers of HPV vaccines.

GENETIC DIFFERENCES

Cervical cancer has declined dramatically in the United States because of Pap tests, which are recommended every three years for women 21 to 65.