Author: Louise Gagnon
About one-quarter of women continue to have high-risk human papillomavirus (HPV) after excisional therapy for cervical intraepithelial neoplasia (CIN) 2/3, a study presented here at the 26th International Papillomavirus Conference (IPC) has found.
Women with CIN are at increased risk for developing invasive cervical cancer, and persistent infection of high-risk HPV is a main risk factor for treatment failure, said Wendy Mei, BSc, MLT, the study’s presenting investigator and clinical trials coordinator at the British Columbia Centre for Disease Control, Vancouver, British Columbia.
HPV testing and Pap smear together are more sensitive than using Pap smear alone, noted Mei.
“We wanted to evaluate the impact of implementing ASCCP [American Society for Colposcopy and Clinical Pathology] guidelines in British Columbia,” Mei told attendees here at an oral presentation on July 7. “We also wanted to determine the genotype distribution of women with higher risk HPV to gain insight on vaccine and diagnostics evaluation.”
Researchers used ThinPrep to collect cervical brushings, instead of conventional Pap smear, to permit an aliquot to be tested to determine if the HPV types were high-risk using a DNA test.
Mei and colleagues collected 1,007 specimens and found 25.4% (n = 256) were positive for high-risk HPV. They found HPV 16 in 29.7% of specimens and HPV 18 in 5.5% of specimens.
“HPV 18 was lower than expected, but the treatment options are more effective for HPV 18,” said Mei in an interview.
Investigators found single and multiple high-risk HPV genotypes were identified in 50.8% of specimens and 31.3% of specimens, respectively. As many as 9 genotypes were detected in 1 sample.
“Multiple infections were quite common, and there might be synergistic or competitive relationships where if you have a certain combination of genotypes, it might make the disease worse or prevent another genotype,” said Mei.
Detecting women who carry high-risk HPV genotypes can allow clinicians to streamline their energies to those women who are at greatest threat of developing cervical cancer, Mei explained.
“If we can identify those cases, we can focus our efforts on those at highest risk of developing cervical carcinoma,” said Dr. Mei, noting that women with high-risk HPV can be included in an intense screening program.
Both Digene and F. Hoffman-La Roche Ltd. supplied materials for investigators to conduct the study.
1. Presentation title: HPV Testing of Women in British Columbia Following Excisional Therapy for CIN 2/3. Abstract 414