In this study, the authors analyzed the immunoexpression of p16 in high-risk human papillomavirus DNA-negative normal and nonneoplastic cervical epithelia, in low-grade cervical intraepithelial neoplasia (CIN), high-grade CIN, and squamous cell carcinoma.
Specimens that were positive for p16<sup>INK4A</sup> expression were 5.3 and 16.6 times more likely to be diagnosed as CIN 2 and CIN 3 lesions, respectively, compared to CIN 1 lesions.
Specifically, methylation of p16 was a frequent event in the cervical carcinoma samples, and these figures were statistically significant compared with the normal and cervical intraepithelial neoplasia I cases (P = 0.015 and P = 0.021, respectively).
HPV positivity was strongly associated with p16(INK4A) staining [odds ratios (OR) = 12.8; 95% confidence intervals (CI): 5.2-31.6]. p16(INK4A) staining of CIN1 biopsies at baseline was associated with an increased risk of finding high-grade CIN over 2 years of follow-up (OR = 1.43; 95% CI: 0.52-3.91).
Eleven of the cervical intraepithelial neoplasia 1 lesions showed focal/scattered reactivity expression for p16(Ink4a), and 19 of the CIN 1 lesions had diffuse reactivity.
None of 20 non-neoplastic cervices showed p16 INK4A and MGMT gene hypermethylation, whereas at least one of these genes was hypermethylated with 50.0% (5/10) of CIN I, 65.0% (13/20) of CIN II-III, 70.2% (33/47) of SCC and 85.0% (17/20) of adenocarcinoma. p16 INK4A protein was totally negative in non-neoplastic cervices, but positive with 90.0% of CIN I, 100% of CIN II-III and adenocarcinoma, and 78.7% of SCC.
The positive immunoreactivity for p16 was as follows: CIN I--1/12 (8.3%), CIN II--2/8 (25%), CIN III--31/36 (86.1%), and in invasive tumors-121/142 (85.1%); for cyclin D1 it was CIN I--4/12 (66.6%), CIN II--5/8 (62.5%), CIN III--0%, and invasive tumors--5/142 (3.5%); and for pRb it was CIN I--9/12 (75%), CIN II--5/8(62.5%), CIN III--1/36 (97.2%), and in invasive tumors--41/142 (28.8%).
However, data are insufficient to determine whether p16 overexpression predicts the risk for progression of low-grade cervical intraepithelial neoplasia (CIN).
We compare the HC2 with the real-time PCR hpVIR assay for detection of HPV in follow-up smears of 398 women diagnosed with atypical squamous cells of unknown significance (ASCUS) or low grade cervical intraepithelial neoplasia (CIN 1) in their initial smear.
In women with abnormal smears (cervical intraepithelial neoplasia [CIN] I, II, and III and invasive cancer) HPV infection was detected in 35-40%; this rate seemed to be age-independent. the Peak incidence of CIN appeared several years after that of HPV infection.
Data files of 2 international screening trials, the NIS (n = 3187) and the LAMS (n = 12,114) study cohorts, were combined, and a subcohort of 1865 (n = 854 and n = 1011 for the NIS and the LAMS, respectively) women prospectively followed up for 19.7 (median, 22.2) months was analyzed for different intermediate end-point markers of disease progression to squamous intraepithelial lesion (SIL), cervical intraepithelial neoplasia grade 1 and higher (CIN1+), and CIN grade 2 and higher (CIN2+) as terminal events.
In histopathologic examination, TERC was amplified in 28 of 671 (4.2%) normal, inflammatory, or wart cases; in 17 of 233 (7.3%) cervical intraepithelial neoplasia grade 1 cases (CIN 1); in 27 of 39 (69.2%) CIN 2 cases; in 57 of 67 (85.1%) CIN 3 cases; and in 22 of 23 (95.7%) cervical cancer cases; with pairwise significant difference in each (P < 0.05).
In atypical squamous cells of undetermined significance (ASC-US) cases, colposcopically directed biopsy showed CIN I (CIN is cervical intraepithelial neoplasia) or higher grade lesions in 34.9% of cases younger than 50 years of age and in 17.4% of cases 50 years and older (P= 0.000).
We tested 105 women with low-grade cervical intraepithelial neoplasia (CIN-1), 92 women with CIN-3/carcinoma in situ or invasive cancer (CIN-3/CA), and 94 normal subjects.
Cross-sectional analysis for HLA association with cervical cancer included 1253 Japanese women: normal cytology (NL, n = 341), cervical intraepithelial neoplasia grade 1 (CIN1, n = 505), CIN grade 2 or 3 (CIN2/3, n = 96), or invasive cervical cancer (ICC, n = 311).
The overall HPV positive rate was 44.3% with 18.6% (16/86) for normal/inflamed cervices, 36.4% (32/88) for condyloma, 64.7% (33/51) for cervical intraepithelial neoplasia grade 1 (CIN 1), 37.9% (11/29) for CIN 2, 68.3 (41/60) for CIN 3, and 77.8% (14/18) for carcinoma.
Specifically, methylation of p16 was a frequent event in the cervical carcinoma samples, and these figures were statistically significant compared with the normal and cervical intraepithelial neoplasia I cases (P = 0.015 and P = 0.021, respectively).
The positive immunoreactivity for p16 was as follows: CIN I--1/12 (8.3%), CIN II--2/8 (25%), CIN III--31/36 (86.1%), and in invasive tumors-121/142 (85.1%); for cyclin D1 it was CIN I--4/12 (66.6%), CIN II--5/8 (62.5%), CIN III--0%, and invasive tumors--5/142 (3.5%); and for pRb it was CIN I--9/12 (75%), CIN II--5/8(62.5%), CIN III--1/36 (97.2%), and in invasive tumors--41/142 (28.8%).
However, data are insufficient to determine whether p16 overexpression predicts the risk for progression of low-grade cervical intraepithelial neoplasia (CIN).