An international team of researchers has identified eight strains of the human papillomavirus responsible for more than 90% of cervical cancer cases worldwide, a finding that could help scientists develop the next generation of HPV vaccines, Reuters reports.
Cervical cancer is the second most common cancer in women worldwide, and it is expected to cause 328,000 deaths in 2010. Of the more than 118 different types of HPV that have been identified, about 40 infect the genital tract and 12 are known to cause cervical cancer.
The study — published on Monday in the Lancet — examined 60 years of data from 10,575 cases of invasive cervical cancer in 38 countries across Europe, North and South America, Africa and Oceania.
The findings found that more than 90% of cervical cancer cases were caused by eight strains of HPV — types 16, 18, 45, 33, 31, 51, 58 and 35, in descending order of frequency. The researchers also identified several rare types of HPV — types 26, 30, 61, 67, 69, 82 and 91 — that can cause cervical cancer but account for only 1% of cases worldwide.
Silvia de Sanjose, the lead author and a researcher at the Catalan Institute of Oncology in Barcelona, Spain, said the findings support “the rationale for prevention of cervical cancer through the use of existing vaccines” and could assist the development of second-generation HPV vaccines. GlaxoSmithKline’s Cervarix and Merck’s Gardasil are the only vaccines against HPV, protecting against types 16 and 18, which cause cervical cancer.
In a Lancet commentary about the study, Cosette Wheeler of the University of New Mexico Health Sciences Center wrote that the research is “a Herculean effort that might be a benchmark for all time.
” Wheeler added that the findings “clearly support future directions for cervical screening and type-specific triage, establish the potential worldwide impact of current HPV vaccines, and set priorities for next-generation vaccines” (Kelland, Reuters, 10/17).
National Partnership for Women & Families