High-risk human papillomavirus (HPV) infection persisted significantly more often in young African-American women than in white women, suggesting an explanation for the increased cervical cancer risk in African Americans, investigators reported at the American Association for Cancer Research meeting.
More than twice as many African-American women continued to test positive for high-risk HPV strains two years after diagnosis, and they were 70% more likely than white women to have abnormal Pap smears.
Because the incidence of HPV infection was similar in African-American and white women, slower viral clearance was the most likely explanation for persistent infection, according to Kim Creek, PhD, of the South Carolina College of Pharmacy in Charleston, and colleagues.
“We propose that an increase in high-risk HPV persistence in African-American women may provide a biological basis for the higher incidence of cervical cancer found in African-American women,” Creek said at an AACR press briefing.
“The reason for slower clearance of high-risk HPV infection in African-American participants is unknown and is actively being studied.”
Incidence and Prevalence of Cervical Cancer
Cancer of the cervix is the second most common cancer in women worldwide and is a leading cause of cancer-related death in women in underdeveloped countries. Worldwide, approximately 500,000 cases of cervical cancer are diagnosed each year.
Routine screening has decreased the incidence of invasive cervical cancer in the United States, where approximately 13,000 cases of invasive cervical cancer and 50,000 cases of cervical carcinoma in situ (i.e., localized cancer) are diagnosed yearly.
Invasive cervical cancer is more common in women middle aged and older and in women of poor socioeconomic status, who are less likely to receive regular screening and early treatment. In the United States, there is also a higher rate of incidence among African American, Hispanic, and Native American women.
African-American women have a 40% higher incidence of cervical cancer and are more than twice as likely white women to die of the disease. Women in the two racial groups have similar rates of screening Pap smears, leading to speculation that the increased cervical cancer risk in African-American women has a biologic basis, said Creek.
To search for a such an explanation, Creek and colleagues analyzed data from the Carolina Women’s Care Study, a 5-year investigation of HPV infection in young women.
The study involved 326 European-American women and 113 African-American women enrolled at the University of South Carolina. All of the women were sexually active, and study participants had Pap smears every six months for the duration of their enrollment.
What are the key statistics about cervical cancer?
The American Cancer Society’s most recent estimates for cervical cancer in the United States are for 2012:
- About 12,170 new cases of invasive cervical cancer will be diagnosed.
- About 4,220 women will die from cervical cancer.
Some researchers estimate that non-invasive cervical cancer (carcinoma in situ) occurs about 4 times more often than invasive cervical cancer.
Cervical cancer was once one of the most common causes of cancer death for American women. Then, between 1955 and 1992, the cervical cancer death rate declined by almost 70%. The main reason for this change was the increased use of the Pap test. This screening procedure can find changes in the cervix before cancer develops. It can also find cervical cancer early - in its most curable stage. The death rate from cervical cancer continued to decline until 2003. Since then it has remained stable in white women, but has gone down in African American women.