Factors associated with HPV persistence after conization in patients with negative margins

The clearance rate of human papillomavirus (HPV) after conization is generally high, although some HPV infections persist. We investigated the factors that affect the clearance of HPV after conization in patients with negative margins.

We retrospectively analyzed 77 patients (mean age 39.9 years, range 25 to 51 years) with CIN 2/3 who underwent loop electrosurgical excision procedure (LEEP) conization with negative margins. All patients had a Pap smear and high-risk (HR) HPV testing using Hybrid Capture II system and HPV DNA chip before conization. We used>/=1 relative light units (RLUs) as the cutoff for persistence of HPV after conization.

High-risk HPV was detected in 73 of 77 (94.8%) patients before conization. At the 6-months follow-up, the high-risk HPV was eliminated in 60 of 73 (82.2%) patients. The HPV persistence rate after conization was 17.8% (13/73). Univariate analysis showed that persistent HPV infection after conization with negative margins was more likely to occur when the pretreatment viral load was high (RLU/positive control >100 (p=0.027) and the HPV was type 16 (p=0.021). Logistic regression analysis showed that preoperative HPV type 16 infection was the only significant independent factor (p=0.021) for HPV persistence out of age, cytology, punch biopsy histology, HPV viral load, and conization histology.

Conization effectively removes HR-HPV infection. HPV type 16 infection before conization was significantly related to HR-HPV persistence after conization with negative margins. Therefore, patients with HPV 16 infection before conization need to be followed closely.