Dr. Philip E. Castle, of the National Cancer Institute, Bethesda, Maryland, and colleagues retrospectively analyzed rates of acquisition of new HPV infections in 195 HPV-positive women who underwent colposcopy and were treated by LEEP for CIN2/3 and a comparison group of 1625 HPV-positive women who underwent colposcopy but not LEEP.
“Our study found a slight reduction in acquisition of new carcinogenic HPV infections” after LEEP, particularly those due to HPV phylogenetic species group 9, which include HPV-16 and is composed predominately of carcinogenic HPV genotypes, the researchers report in the Journal of Infectious Diseases for June 1st.
Specifically, women who underwent LEEP relative to those that did not were 56% less likely to have HPV 16 and other high-risk carcinogenic genotypes of phylogenetic species group 9 detected at 6 months and 40% less likely to have these genotype detected at 24 months.
It is possible, the researchers say, that LEEP, “by damaging the cervical tissue, causes an acute inflammatory response that reduces the susceptibility of new HPV infections, but there is not evidence to support such a mechanism or to explain why it would be specific to HPV-16-related genotypes.”
They emphasize that due to limitations in the study design, it is not possible to draw a definitive conclusion about the protective effect of LEEP on acquisition of HPV infection, and they urge caution against over interpretation of the study findings.
J Infect Dis 2009;199:1612-1620.