Although doctors have known that the cervical tissue at the opening to the womb can harbor multiple human papillomavirus (HPV) types, this study is the first to document that the risk for developing cervical cancer, the second most common form of cancer in women worldwide, is higher in females infected with multiple HPV types than those infected with just one HPV type.
In addition, the study’s findings provide baseline data for analyzing over time the impact of the newly approved vaccine, Merck & Co’s Gardasil, on the dynamics of HPV infection.
Like previous studies on HPV in cervical cancer, the new research found that precancerous abnormalities primarily occurred in women infected with HPV 16 and 18, the targets of Gardasil.
The vaccine will also prevent infection by the HPV types 6 and 11 that are associated with genital warts, and thus is expected to prevent cervical cancer in thousands of women.
However, the vaccine will not protect against HPV 58, which the new study discovered to be far more oncogenic than others when found in co-infections with other HPV types. The study’s findings suggest HPV 58 should be one of the targets of the next generation of cervical cancer vaccines.
The study results suggest that the current method that doctors use for HPV screenings – the pap smear – should be replaced with a test that detects the presence of a HPV co-infection and identifies each HPV genotype. If an infection is present, the current test cannot determine whether it was triggered by just one genotype or multiple types of HPV.