Follow-up study of patients with cervical intraepithelial neoplasia grade 1 overexpressing p16Ink4a.

OBJECTIVE: The p16 (p16(Ink4a)) tumor-suppressor protein is a biomarker for activated expression of human papillomavirus oncogenes. However, data are insufficient to determine whether p16 overexpression predicts the risk for progression of low-grade cervical intraepithelial neoplasia (CIN). This study was aimed at evaluating the risk for progression to CIN2 or worse during a 3-year follow-up of an unselected series of 739 patients with CIN1 biopsy specimens tested for p16 expression. METHODS: Positivity of p16 was defined as a diffuse overexpression in the basal/parabasal cell layers. Selection biases were ruled out using a control group of 523 patients with CIN1 biopsies not tested for p16 expression. Analysis was based on the ratio of progression rates. RESULTS: In the first year of follow-up, the 216 patients (29%) with p16-positive CIN1 had a higher progression rate (12.3%) than did the 523 patients with p16-negative CIN1 (2.2%) (rate ratio, 5.5; 95% confidence interval [CI], 2.59-11.71). In the second and third years, differences were smaller (rate ratio, 1.32 and 1.14, respectively) and not significant. The patients with p16-positive CIN1 also had a lower risk for regression to normal in the first year of follow-up (rate ratio, 0.55; 95% confidence interval, 0.42-0.71) and nonsignificant changes in the second and third years (rate ratio, 0.81 and 0.84, respectively). CONCLUSIONS: The patients with p16-positive CIN1 had an increased risk for progression that was concentrated in the first year of follow-up. Immunostaining of p16 could have a role in short-term surveillance of patients with CIN1. Further research should focus on midterm/long-term outcomes of p16-positive CIN1.

The risk of false-positive histology according to the reason for colposcopy referral in cervical cancer screening: a blind revision of all histologic lesions found in the NTCC trial.

All cervical intraepithelial neoplasia (CIN) diagnoses identified during the New Technologies for Cervical Cancer trial (ISRCTN81678807) were blindly reviewed by 2 pathologists. Original diagnoses based on colposcopy-guided biopsies were compared with those made by the reviewers who had access to all clinical histologic samples (including postsurgical). Cases downgraded from CIN 2+ by the reviewers were considered indicative of unnecessary treatments. The analyses are presented according to the molecular (high-risk human papillomavirus [HPV]) and/or cytologic diagnosis used to refer the women for colposcopy. We reviewed 812 CIN 1 and 364 CIN 2 + diagnoses. The specificity of colposcopy-guided biopsy was 98% and the sensitivity, 84%. The probability of unnecessary treatment was 27% for women with atypical squamous cells of undetermined significance cytologic findings and 8% for women with low-grade squamous intraepithelial lesion or worse, 10% for HPV+ and positive cytologic findings, and 16% for HPV+ alone. The positive predictive value of the first-level screening test was inversely associated with probability of a histologic false-positive result (P = .015). In screening, a low positive predictive value of the colposcopy-referring test may result in unnecessary treatments.

The reproducibility of CIN diagnoses among different pathologists: data from histology reviews from a multicenter randomized study.

The reproducibility of cervical histology diagnoses is critical for efficient screening and to evaluate the effectiveness of new technologies. The vast majority of cervical intraepithelial neoplasia (CIN) diagnoses reported in the New Technologies for Cervical Cancer study were blindly reviewed by 2 independent pathologists. Only H&E-stained slides were used for the review. The reviewers were asked to reclassify cases using the following categories: normal CIN 1, CIN 2, CIN 3, and squamous and glandular invasive cancer. We reviewed 1,003 cases. The interobserver agreement was 0.36 (95% confidence interval [CI], 0.32-0.40) with an unweighted kappa and 0.54 with a weighted kappa (95% CI, 0.50-0.58). The kappa values from dichotomous classifications with the threshold at CIN 2 were 0.69 (95% CI, 0.64-0.73) and 0.57 (95% CI, 0.51-0.63) with the threshold at CIN 3. The CIN 2 diagnosis had the lowest class-specific agreement, with fewer than 50% of cases confirmed by the panel members, which supports the fact that CIN 2 is not a well-defined stage in the pathogenesis of cervical neoplasia.