March 24 (HealthDay News) -- The majority of invasive cervical cancers in New Mexico in the 1980s and 1990s contained DNA from human papillomavirus type 16 (HPV16) and HPV type 18 (HPV18), says a new study.
It also found that women diagnosed with HPV16- or HPV18-positive cancers were an average of five years younger than those diagnosed with cancers associated with other HPV types.
The HPV vaccine (Gardasil) protects against infections caused by HPV16 and HPV18, so the new findings may have implications for future cancer screening programs, the researchers said.
The researchers analyzed U.S. data in the Surveillance, Epidemiology and End Results registry and identified 1,213 cases of in situ cervical cancer diagnosed between 1980 and 1999, as well as 808 cases of invasive cervical cancer diagnosed between 1980 and 1999 in New Mexico.
HPV16 DNA was found in 53.2 percent of invasive cervical cancers, HPV18 DNA was found in 13.1 percent, and HPV45 DNA in 6.1 percent. HPV16 DNA was found in 56.3 percent of in situ cervical cancers, HPV31 DNA in 12.6 percent, and HPV33 DNA in 8 percent.
Patients' median age at diagnosis of invasive cancer with HPV16 and HPV18 was 48.1 years, and 45.9 years, respectively. Median age at diagnosis of invasive cancer with other HPV genotypes was 52.3 years.
The study is in the March 24 online issue of the Journal of the National Cancer Institute.
"To our knowledge, this is the largest study of its kind conducted in a U.S. population," wrote a team led by Cosette M. Wheeler, of the University of New Mexico Health Sciences Center in Albuquerque.
"This study of HPV genotypes in New Mexico provides important baseline data for evaluating the effectiveness of nearly implemented HPV-based technologies, HPV vaccines, and HPV screening in the prevention of cervical cancer," she said. "Moreover, these data can guide the future application of these technologies to maximize the cost-effective, public health benefits of these interventions."
SOURCE: Journal of the National Cancer Institute, news release, March 24, 2009