The negative predictive value of p16INK4a to assess the outcome of cervical intraepithelial neoplasia 1 in the uterine cervix

Utility of p16/Ki67 double immunocytochemistry for detection of cervical adenocarcinoma

BACKGROUND

Although the incidence of cervical adenocarcinoma has consistently increased, especially among young women, there is no established best means for screening. This study evaluated the screening efficacy of CINtec PLUS (CINtec; p16/Ki67 double immunocytochemistry) expression in cervical glandular cells.

METHODS

Cervical cytology was examined using abnormal glandular cells. The CINtec status of 100 samples with corresponding surgically resected specimens and 11 samples that exhibited negative results for intraepithelial lesion or malignancy at follow-up was analyzed. Additionally, 31 negative samples containing benign glandular cells were included.

RESULTS

Of the 142 samples, CINtec status was diffusely positive in 74, focally positive in 24, and negative in 44. The 74 diffusely positive samples included 70 adenocarcinomas (62 cervical, seven uterine, and one ovarian) and four cases of high-grade cervical intraepithelial neoplasia. The 24 focally positive samples included 15 adenocarcinomas (seven cervical, seven uterine, and one fallopian tube) and nine without malignancy. The 44 negative samples included nine adenocarcinomas (five uterine and four cervical) and 35 without malignancy. The sensitivity, specificity, positive predictive value, and negative predictive value of the CINtec diffusely or focally positive cases for cervical adenocarcinomas were 94.5%, 58.0%, 70.4%, and 90.9%, respectively. In CINtec diffusely positive cases, the respective values were 84.9%, 82.6%, 83.8%, and 83.8%, and in women aged ≤39 years the values were 90.6%, 89.5%, 93.5%, and 85.0%, respectively.

CONCLUSIONS

CINtec may support efficient detection of cervical adenocarcinomas.

The Natural History of Cervical Intraepithelial Neoplasia Grades 1, 2, and 3: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study was to obtain an updated overview of regression, persistence, and progression rates of conservatively managed cervical intraepithelial neoplasia grade 1 (CIN 1)/CIN 2/CIN 3.

METHODS

Data sources were MEDLINE, Embase, and Cochrane (January 1, 1973-April 14, 2020). Two reviewers extracted data and assessed risk of bias. To estimate outcome rates, we pooled proportions of the individual study results using random-effects meta-analysis, resulting in point estimates and corresponding 95% CIs. Heterogeneity was quantified by the I2 and τ2 measures.

RESULTS

Eighty-nine studies were included, 63 studies on CIN 1 (n = 6,080-8,767), 42 on CIN 2 (n = 2,909-3,830), and 7 on CIN 3 (n = 245-351). The overall regression, persistence, and progression to CIN 2 or worse and CIN 3 or worse rates for women with conservatively managed CIN 1 were 60% (95% CI = 55-65, I2 = 92%), 25% (95% CI = 20-30, I2 = 94%), 11% (95% CI = 8-13, I2 = 89%), and 2% (95% CI = 1-3, I2 = 82%), respectively. The overall regression, persistence, and progression rates for CIN 2 were 55% (95% CI = 50-60, I2 = 85%), 23% (95% CI = 19-28, I2 = 83%), and 19% (95% CI = 15-23, I2 = 88%), respectively. Finally, for CIN 3, these were 28% (95% CI = 17-41, I2 = 68%), 67% (95% CI = 36-91, I2 = 84%), and 2% (95% CI = 0-25, I2 = 95%), respectively. Cervical intraepithelial neoplasia grade 2 regression was significantly higher in women 30 years or younger and high-risk human papillomavirus-negative women (66%, 95% CI = 62-70, I2 = 76%; 94%, 95% CI = 84-99, I2 = 60%). Only 2/7,180 (0.03%) and 10/3,037 (0.3%) of the CIN 1 and CIN 2 cases progressed to cervical cancer.

CONCLUSIONS

Most CIN 1/CIN 2 will regress spontaneously in less than 24 months, with the highest rates in high-risk human papillomavirus-negative and young women, whereas progression to cancer is less than 0.5%. Conservative management should be considered, especially in fertile women and with expected high compliance. Given the heterogeneity in regression rates of high-grade histology, this should be classified as CIN 2 or CIN 3 to guide management.

Predictive value of p16INK4a, Ki-67 and ProExC immuno-qualitative features in LSIL progression into HSIL

The current nested case-control study was conducted to explore the prognostic value of cyclin-dependent kinase inhibitor 2A (p16^INK4a), marker of proliferation Ki-67 (Ki-67) and immunohistochemical cocktail containing antibodies directed against topoisomerase IIα (TOP2A) and minichromosome maintenance 2 (MCM2) proteins (ProExC) immuno-qualitative features to predict low-grade squamous intraepithelial lesion (LSIL) progression. A total of 92 LSIL patients were followed-up for 2 years, where those with high-grade squamous intraepithelial lesion (HSIL) or persistent LSIL were designated as the case group and those who spontaneously regressed were designated as the control group. The infection status of human papillomavirus (HPV) was evaluated using flow-through hybridization and gene chip, whilst the expression of p16^INK4a, Ki-67 and ProExC were tested in LSIL patient biopsies by immunohistochemistry. All data were collected at the beginning of the follow-up and patient outcomes were diagnosed by histopathological examination. To analyze the risk factors for LSIL progression, sensitivity, specificity, positive-negative predictive value (PPV-NPV), positive-negative likelihood ratio (PLR-NLR), Youden's index (YI) and multinomial logistic regression analysis was performed. The expression rates of p16^INK4a, Ki-67, and ProExC were found to be higher in the progression group compared with those in the persistence and regression groups. Only p16^INK4a expression significantly associated with high-risk HPV infection. With respect to predicting HSIL, p16^INK4a staining was the most sensitive but Ki-67 staining was found to be the most specific. YI was the highest (42.1%) for p16^INK4a expression in the present study, followed by ProExC (39.5%) and Ki-67 (28.3%). However, the expression of ProExC was found to be an independent risk factor for LSIL progression into HSIL. In conclusion, whilst immunohistochemical staining for p16^INK4a, Ki-67, and ProExC can be used to predict HSIL progression, only ProExC expression can be applied an independent risk factor for LSIL progression.

Grading immunohistochemical markers p16INK4a and HPV E4 identifies productive and transforming lesions caused by low- and high-risk HPV within high-grade anal squamous intraepithelial lesions

OBJECTIVES

Because current guidelines recognise high-grade anal squamous intraepithelial lesions (HSILs) and low-grade SILs (LSILs), and recommend treatment of all HSILs although not all progress to cancer, this study aims to distinguish transforming and productive HSILs by grading immunohistochemical (IHC) biomarkers p16INK 4a (p16) and E4 in low-risk human papillomavirus (lrHPV) and high-risk (hr)HPV-associated SILs as a potential basis for more selective treatment.

METHODS

Immunostaining for p16 and HPV E4 was performed and graded in 183 biopsies from 108 HIV-positive men who have sex with men. The causative HPV genotype of the worst lesion was identified using the HPV SPF10-PCR-DEIA-LiPA25 version 1 system, with laser capture microdissection for multiple infections. The worst lesions were scored for p16 (0-4) to identify activity of the hrHPV E7 gene, and panHPV E4 (0-2) to mark HPV production and life cycle completion.

RESULTS

There were 37 normal biopsies, 60 LSILs and 86 HSILs, with 85% of LSILs caused by lrHPV and 93% of HSILs by hrHPV. No normal biopsy showed E4, but 43% of LSILs and 37% of HSILs were E4 positive. No differences in E4 positivity rates were found between lrHPV and hrHPV lesions. Most of the lesions caused by lrHPV (90%) showed very extensive patchy p16 staining; p16 grade in HSILs was variable, with frequency of productive HPV infection dropping with increasing p16 grade.

CONCLUSIONS

Combined p16/E4 IHC identifies productive and nonproductive HSILs associated with hrHPV within the group of HSILs defined by the Lower Anogenital Squamous Terminology recommendations. This opens the possibility of investigating selective treatment of advanced transforming HSILs caused by hrHPV, and a 'wait and see' policy for productive HSILs. What's already known about this topic? For preventing anal cancer in high-risk populations, all patients with high-grade squamous intraepithelial lesions (HSILs) are treated, even though this group of lesions is heterogeneous, the histology is variable and regression is frequent. What does this study add? By adding human papillomavirus (HPV) E4 immunohistochemistry to p16 INK4a (p16), and grading expression of both markers, different biomarker expression patterns that reflect the heterogeneity of HSILs can be identified. Moreover, p16/E4 staining can separate high-risk HPV-associated HSILs into productive and more advanced transforming lesions, providing a potential basis for selective treatment.

p16INK4a, Cytokeratin 7, and Ki-67 as Potential Markers for Low-Grade Cervical Intraepithelial Neoplasia Progression

OBJECTIVE

The aim of this study was to evaluate p16, cytokeratin 7 (CK7), and Ki-67 immunoexpressions in low-grade squamous intraepithelial lesion (LSIL), looking for differences among cases that progress to high-grade squamous intraepithelial lesion, maintain LSIL, or regress.

MATERIALS AND METHODS

Sixty-six LSIL biopsies were studied. In the follow-up, a second biopsy showed 28.7% regression, 37.9% LSIL, and 33.4% progressed to high-grade squamous intraepithelial lesion. Immunostaining for these markers were performed in the first biopsy. A qualitative evaluation method was used, as well as histomorphometry, using ImageJ software. Pearson χ, Mann-Whitney, Kruskal-Wallis, and Fisher tests were used to compare the groups (P ≤ .05). A cutoff point was assessed through receiver operating characteristic curve positive cell ratio, for each marker, as progression predictors.

RESULTS

The mean age of patients with and without progression was 33 and 27 years (P = .006), respectively. The qualitative evaluation indicated a tendency of progression, but without statistical significance. However, through histomorphometry, the receiver operating characteristic curve analysis showed cutoff points of 0.396, 0.345, and 0.026 for p16, CK7, and Ki-67 ratios, respectively, as predictors of progression (P = .003, .03, and .002, respectively). In a logistic regression analysis, p16, CK7, and Ki-67 positive cell ratio showed a significant correlation with progression (P = .036, .012, and .006, respectively).

CONCLUSIONS

p16, CK7, and Ki-67 may represent useful biomarkers that can identify LSIL lesions that need particular attention.

p16 Expression and Biological Behavior of Flat Vulvar Low-grade Squamous Intraepithelial Lesions (LSIL)

Flat low-grade squamous intraepithelial lesion (LSIL) of the vulva [vulvar intraepithelial neoplasia (VIN) 1, flat condyloma] is an uncommon entity with poorly understood biological behavior. We aimed to determine the risk of subsequent vulvar high-grade squamous intraepithelial lesion (HSIL) or carcinoma following a diagnosis of vulvar LSIL/VIN 1, as well as the frequency and predictive value of p16 immunohistochemical expression in this setting. Of the 51 included cases, p16 positivity (diffuse block staining) was identified in 2 (4%). Follow-up data were available in 34 cases, of which 2 (5.9%) developed subsequent vulvar HSIL, including 1/2 p16-positive cases and 1/32 p16-negative cases. The difference in HSIL frequency between p16-positive and p16-negative cases was not statistically significant (P=0.116 for VIN 2+, P=0.061 for VIN 3). For the 18 patients with treatment information available, 10 (56%) received medical or surgical treatment after biopsy. Our results indicate that flat vulvar LSIL is infrequently p16 positive, and that few patients with vulvar LSIL develop subsequent vulvar HSIL. Despite the use of destructive treatment in some cases, the data provide support for the nonpreneoplastic nature of the entity. Immunohistochemical expression of p16 may not be a predictor of HSIL risk in vulvar LSIL, although this result may also be related to the very low rates of both p16 positivity and subsequent vulvar HSIL in our sample. It is clear that vulvar LSIL is distinct from LSIL in other lower anogenital sites in terms of its behavior and p16 expression frequency.

Immunohistochemistry in Gynecologic Pathology: An Example-Based Practical Update

CONTEXT

- Immunohistochemical stains are routinely applied in the pathology diagnostic workup of gynecologic lesions. The rapidly expanding repertoire of available markers helps in refining the diagnostic criteria for each disease entity; however, limitations and pitfalls exist.

OBJECTIVE

- To provide a practical, relevant update on the use of immunohistochemistry for commonly encountered differential diagnoses in gynecologic pathology.

DATA SOURCES

- Literature review and authors' diagnostic experience.

CONCLUSIONS

- Immunohistochemistry is a helpful adjunct tool in gynecologic pathology. Although the primary application is in the diagnostic workup, novel prognostic and predictive markers, and immunostains to screen for genetic cancer syndromes, have also been recently introduced in the field.

Expression of geminin, p16, and Ki67 in cervical intraepithelial neoplasm and normal tissues

Geminin is a protein involved in cell cycle progression. We aimed to evaluate the diagnostic value of geminin expression in cervical intraepithelial neoplasm (CIN).The expression of geminin, p16, and Ki67 was examined in 95 samples, including CIN1 (n = 45), CIN2/3 (n = 40), and normal cervical tissues (n = 10) by immunohistochemistry. The correlation between geminin or p16 expression and human papillomavirus (HPV) status was also evaluated.Geminin expression was negative in all normal tissues and expressed in 13.3% of CIN1 and 90.0% of CIN2/3. P16 expression was demonstrated in 24.4% of CIN1 and 87.5% of CIN2/3. The corresponding Ki67 expression was 35.6% and 95.0%. The specificity of geminin for differentiating between CIN1 and CIN2/3 was 86.7%, while for p16 and Ki67 the corresponding values were 75.6% and 64.4%. The sensitivity of geminin, p16, and Ki67 was 90.0%, 87.5%, and 95.0%, respectively. The positive predictive value (PPV) and accuracy of geminin were higher than p16 and Ki67. In addition, geminin expression showed a weak correlation with HPV status, but there was no association between p16 expression and HPV status.These results suggested that geminin had a high degree of sensitivity and specificity in determining CIN2/3. In addition to p16 and Ki67, geminin might be used as a new biomarker to distinguish between CIN1 and CIN2/3.

Disparities in Cervical Cancer Incidence and Mortality: Can Epigenetics Contribute to Eliminating Disparities?

Screening for uterine cervical intraepithelial neoplasia (CIN) followed by aggressive treatment has reduced invasive cervical cancer (ICC) incidence and mortality. However, ICC cases and carcinoma in situ (CIS) continue to be diagnosed annually in the United States, with minorities bearing the brunt of this burden. Because ICC peak incidence and mortality are 10-15 years earlier than other solid cancers, the number of potential years of life lost to this cancer is substantial. Screening for early signs of CIN is still the mainstay of many cervical cancer control programs. However, the accuracy of existing screening tests remains suboptimal. Changes in epigenetic patterns that occur as a result of human papillomavirus infection contribute to CIN progression to cancer, and can be harnessed to improve existing screening tests. However, this requires a concerted effort to identify the epigenomic landscape that is reliably altered by HPV infection specific to ICC, distinct from transient changes.

p16ink4 and cytokeratin 7 immunostaining in predicting HSIL outcome for low-grade squamous intraepithelial lesions: a case series, literature review and commentary

p16ink4 and cytokeratin 7 (CK7) have been proposed to identify low-grade squamous intraepithelial lesions (LSIL) at greater or lesser risk for an outcome of high-grade squamous intraepithelial lesion (HSIL). We correlated CK7 and p16ink4 staining in LSILs with outcome on follow-up and placed this information in the context of prior reports. Cervical LSIL biopsies with at least 1-year follow-up information were immunostained for CK7 and p16ink4. Follow-up outcomes included no SIL, LSIL (persistence) or HSIL (CIN2+). In all, 109 LSILs were studied and 18.3% stained positive for CK7. Ninety-one percent of CK7-negative LSILs regressed, 4.5% persisted, and 4.5% had an HSIL outcome, versus 60, 20, and 20% of CK7-positive LSILs, respectively (P=0.036). p16ink4 status did not significantly associate with outcome. Review of the literature revealed a highly variable rate of both positive p16ink4 immunoreactivity in LSIL and CIN2+ outcome for p16-positive LSIL but a consistently high negative predictive value (>90%) in the case of no/low p16 expression. Inter-observer reproducibility for the diagnosis of CIN2 in the literature ranged from poor to good, with unanimous agreement on the diagnosis of CIN2 occurring in less than 25% of cases. As with high-risk human papillomavirus testing, the most clinically useful result of p16ink4 staining is a negative test, implying no lesion or CIN1 and conferring a low risk of HSIL outcome. HSIL outcomes ('progression') are highly variable and are subject to wide differences in inter-observer interpretation for CIN2. This argues against the wisdom of relying on p16ink4 to both predict CIN2+ or upgrade CIN1 to CIN2. It also begs the question of whether CIN2 should be replaced by an alternate and less pejorative term (SIL of intermediate grade) for lesions that are not reproducibly classified as LSIL or HSIL, with an appropriate management scheme.

Expression of Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16 in cervical dysplasia

AIM

Cervical intraepithelial neoplasia (CIN) is commonly divided into three grades. Guidelines increasingly recommend surgery only in CIN 3 lesions. We investigated markers to evaluate differences in CIN 2 and 3 lesions as well as possible predictors for regression/progression in CIN 2 lesions.

MATERIALS & METHODS

Biopsies (n = 128) of healthy cervical tissue and CIN 1-3 were stained for Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16.

RESULTS

We observed significant differences between CIN 2 and 3 lesions for Sialyl Lewis a, Sialyl Lewis x, Gal-3, Gal-7, STMN1 and p16. Expression of Sialyl Lewis a was significantly higher in CIN 2 patients who progressed during follow-up.

CONCLUSION

Significant differences in marker expression support the differentiation of CIN 2 and 3. Lewis a may help to predict progression/regression in CIN 2 patients.

Effect of Lower Anogenital Squamous Terminology Recommendations on the Use of p16 Immunohistochemistry and the Proportion of High-Grade Diagnoses in Cervical Biopsy Specimens

OBJECTIVES

The Lower Anogenital Squamous Terminology (LAST) group has recommended that cervical intraepithelial neoplasia (CIN) terminology be replaced by squamous intraepithelial lesion (SIL) terminology, with p16 immunohistochemistry used to separate lesions formerly diagnosed as CIN grade 2 into high-grade SILs (HSILs) and low-grade SILs. This study investigated the impact of these changes on the frequency of p16 testing and the diagnosis of high-grade lesions.

METHODS

Pathology reports for all cervical biopsy specimens in the 1 year before and after the introduction of LAST recommendations (July 2011 to June 2013) were examined.

RESULTS

Before and after the implementation of LAST, 365 (15.4%) of 2,376 cases were diagnosed as high grade (CIN 2/3) vs 486 (17.6%) of 2,761 cases diagnosed as HSILs (P = .0343), and p16 was performed 79 (3.3%) times vs 383 (13.9%) times (P < .0001).

CONCLUSIONS

Immunohistochemistry for p16 increased dramatically as a result of LAST recommendations, and high-grade diagnoses increased.

Role of the Biomarker p16 in Downgrading -IN 2 Diagnoses and Predicting Higher-grade Lesions

In 2012, the College of American Pathologists and American Society for Colposcopy and Cervical Pathology published the "LAST" recommendations for histopathology reporting of human papilloma virus-related squamous lesions of the lower anogenital tract, including the use of a 2-tier nomenclature (low-grade squamous intraepithelial lesion/high-grade squamous intraepithelial lesion [LSIL/HSIL]) and expanded use of the biomarker p16 to classify equivocal lesions as either precancer (HSIL) or low-grade lesions (LSIL)/non-human papilloma virus changes. We aimed to determine (1) the frequency with which the poorly reproducible diagnosis of intermediate-grade (-IN 2) lesion in the lower anogenital tract would be downgraded on the basis of p16 results, and (2) whether p16 status was predictive of subsequent higher-grade lesions. A total of 200 specimens diagnosed as an intermediate-grade (-IN 2) lesion of the cervix (168), vagina (2), vulva (2), and anus (28) were reviewed and immunostained for p16. Slides were independently reviewed by 2 pathologists, with discrepant p16 interpretations adjudicated by a third pathologist. Of the 200 cases, 32% were negative for p16. Among the 166 patients with subsequent pathology (including 131 excisions), 26.2% of p16-positive cases versus 4.4% of p16-negative cases were associated with a subsequent diagnosis of HSIL (-IN 3) or worse (P=0.002). Reproducibility of the biopsy diagnosis was fair, with no significant difference with the addition of p16 or using 2 versus 3 tiers. In 11.5% of cases, there was discordance in p16 interpretation (κ 0.735, good agreement). The results indicate that using the Lower Anogenital Squamous Terminology recommendations would result in approximately one third of equivocal (-IN 2) diagnoses being downgraded to LSIL over 1 year in a busy academic practice. The significant association of p16 expression with a higher risk for HSIL on a subsequent specimen suggests that use of p16 to adjudicate equivocal (-IN 2) diagnoses in lower anogenital tract specimens as either LSIL or HSIL would likely predict lesion grade more accurately and avoid unnecessary excisional procedures.

p16 staining has limited value in predicting the outcome of histological low-grade squamous intraepithelial lesions of the cervix

In order to evaluate the usefulness of p16 staining in predicting the outcome of histological low-grade squamous intraepithelial lesion/cervical intraepithelial neoplasia grade 1 (LSIL/CIN1) we prospectively recruited all the patients referred to colposcopy from 2003 to 2011 due to abnormal screening test results and diagnosed with LSIL/CIN1 at biopsy (n=507). All biopsies were stained for p16 and re-evaluated after three years by the same gynecological pathologist using the LAST criteria. Follow-up was conducted every 6 months and included a Pap test (liquid-based cytology), high-risk human papillomavirus testing (Hybrid Capture 2 test), and colposcopy. The mean follow-up was 28 months. An outcome diagnosis of HSIL was defined as a histological diagnosis of high-grade SIL/CIN (HSIL/CIN2-3). The diagnosis of LSIL/CIN1 was confirmed in 416 out of 507 biopsies (82%), whereas 58 (11%) were reclassified as negative and 33 (6%) as HSIL/CIN2-3. During follow-up, 86/507 women initially diagnosed with LSIL/CIN1 (17%) showed an outcome diagnosis of HSIL/CIN2-3, with the rate of HSIL final diagnosis of 3% (2/58) in the women with biopsies reclassified as negative, 17% (70/416) in the group with confirmed LSIL and 42% (14/33) in the women with biopsies reclassified as HSIL (P<0.001). p16 was positive in 245/507 patients (48%) and in 210/416 patients (50%) with confirmed LSIL/CIN1 at re-evaluation. Although positive p16 immunostaining was associated with risk of HSIL/CIN2-3 outcome in the multivariate analysis (Hazard ratio (HR) 1.9; 95% confidence interval (CI): 1.2-3.1; P=0.009) in the overall group of patients with LSIL/CIN1, this association was not verified in the subset of patients with confirmed LSIL/CIN1 after re-evaluation (HR: 1.6; 95% CI: 0.9-2.6; P=0.095). In conclusion, in LSIL/CIN1 lesions p16 should be limited to equivocal cases in which HSIL/CIN2 is included in the differential diagnosis since it has low value in clinical practice as a marker of progression of LSIL/CIN1.

mRNA biomarker detection in liquid-based cytology: a new approach in the prevention of cervical cancer

Several high-risk human papillomavirus (HPV)-induced cell biomarkers have been proposed as possible candidates to identify patients harboring high-grade squamous intraepithelial lesions (HSILs) of the uterine cervix. We aimed to determine the feasibility of the detection of the mRNA of six biomarkers in cervical smear specimens obtained by liquid-based cytology and to evaluate whether this approach might be useful in the identification of patients with HSIL. One-hundred and twenty three women referred to colposcopy in the Hospital Clinic of Barcelona were included in the study. After a thorough study, including Pap test, high-risk HPV testing (Hybrid Capture 2 test), and colposcopy with directed biopsy and/or endocervical curettage, 48 patients were diagnosed with HSIL, whereas 75 were classified as negative (n=28), or harboring low-grade SIL (n=47). CDKN2A/p16, BIRC5, MMP9, TOP2A, MCM5, and MKI67 mRNA expression was analyzed by reverse transcription quantitative polymerase chain reaction in liquid-based cytology after the Pap test and Hybrid Capture 2 performance. The tissue expression of these biomarkers was analyzed by immunohistochemistry in the biopsy material. One-hundred and thirteen out of 123 (92%) liquid-based cytology yielded adequate material for mRNA analysis. TOP2A was the most sensitive (97%) biomarker for the detection of HSIL and CDKN2A/p16 the most specific (78%). The combination of TOP2A and CDKN2A/p16 showed a sensitivity of 96% (95% confidence interval (CI): 88-99) and a specificity of 71% (95% CI: 55-82). In the immunohistochemistry analysis, all biomarkers showed a high sensitivity but low specificity for HSIL, except CDKN2A/p16 which had a sensitivity of 100% and a specificity of 63%. The combination of TOP2A and CDKN2A/p16 showed a sensitivity of 100% (95% CI: 91-100) and a specificity of 43% (95% CI: 32-55). The detection of mRNA of cell biomarkers in liquid-based cytology material is feasible. The combination TOP2A and CDKN2A/p16 has a good balance between sensitivity and specificity for the detection of women with HSIL.

HPV-related squamous neoplasia of the lower anogenital tract: an update and review of recent guidelines

Squamous cell carcinomas of the lower anogenital tract that are related to human papillomavirus (HPV) infection represent a significant disease burden worldwide. The diagnosis and management of their noninvasive precursors has been the subject of extensive study and debate over several decades, accompanied by an evolving understanding of HPV biology. Recent new consensus recommendations for the pathologic diagnosis of these precursor lesions were published in 2012, the result of the Lower Anogenital Squamous Terminology project cosponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology. Most salient among the new guidelines are the recommendation to switch to a 2-tiered nomenclature (high-grade squamous intraepithelial lesion and low-grade squamous intraepithelial lesion) rather than the traditional 3-tiered "intraepithelial neoplasia" terminology, and the recommendation to expand use of the immunohistochemical marker p16 to distinguish between low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion/intraepithelial neoplasia 2. The goals of the project were to align diagnostic terminology with our knowledge of HPV biology, increase reproducibility, consolidate diverse systems of nomenclature, and ultimately better determine a patient's true cancer risk. The clinical guidelines for screening and management of cervical intraepithelial neoplasia have also been recently updated, most notably with a lengthening of screening intervals. In this review, we focus on the new guidelines put forth for pathologic diagnosis of HPV-related anogenital neoplasia, with discussion of the evidence behind them and their potential implications. We also provide an update on relevant biomarkers, clinical recommendations, and the newest developments relating to cervical neoplasia.

Methylated ZNF582 gene as a marker for triage of women with Pap smear reporting low-grade squamous intraepithelial lesions - a Taiwanese Gynecologic Oncology Group (TGOG) study

OBJECTIVE

Our previous work revealed that host genes ZNF582, PTPRR, PAX1, and SOX1 are highly methylated in cervical intraepithelial neoplasias grade 3 or worse (CIN3(+)). In this study, we used a standardized testing assay to evaluate the clinical efficacy of these biomarkers in the triage of cytological diagnoses of low-grade squamous intraepithelial lesions (LSILs), and compared the performance with human papillomavirus (HPV) testing.

METHODS

This 2-year multicenter prospective study examined a population of 230 women from 12 medical centers who were diagnosed with LSILs on cervical cytology. Cervical scrapings were obtained prior to a colposcopy-directed biopsy for quantitative methylation analysis of ZNF582, PTPRR, PAX1, and SOX1, and HPV testing. Using logistic regression and receiver operating characteristic curve analyses, the abilities of methylated genes and HPV to predict CIN3(+) were assessed.

RESULTS

Fifteen (6.5%) of the 230 women with a cytological diagnosis of LSIL were confirmed to have CIN3(+) after a colposcopy-directed biopsy. Among the 4 methylated genes, ZNF582 was found to be the best biomarker for detecting CIN3(+). The sensitivities for methylated ZNF582 and HPV testing were 73% and 80%, and the specificities were 71% and 28%, respectively. The odds ratio for predicting CIN3(+) using methylated ZNF582 was 6.8 (95% confidence interval (CI) 2.1-22.1), which was much better than HPV testing (OR=1.6, 95% CI 0.4-5.8).

CONCLUSION

This is the first study to show that ZNF582 methylation analysis of cervical swabs may be a promising choice in the positive triage of cytological diagnoses of LSILs.

Assessment of correlation between p16INK4a staining, specific subtype of human papillomavirus, and progression of LSIL/CIN1 lesions: first comparative study

OBJECTIVES

To study and compare the effectiveness of p16(INK4a) staining and specific human papillomavirus (HPV) subtypes as a prognostic marker in cervical intraepithelial neoplasia grade 1 (CIN1; low-grade squamous intraepithelial lesions).

METHODS

Sixty-four cervical samples diagnosed as CIN1 and stained with p16(INK4a), with HPV status assessed by polymerase chain reaction-direct sequencing.

RESULTS

Of the 34 p16(INK4a)-negative biopsy specimens, 26 regressed, seven persisted, and one progressed. Of the 20 p16(INK4a) diffusely positive biopsy specimens, seven regressed, eight persisted, and five progressed. Ten biopsy specimens stained positive only in the lower one-third of the sample, of which seven regressed and three persisted. p16(INK4a) diffusely positive CIN1 lesions were associated with only high-risk HPV subtypes, with the exception of one HPV-negative biopsy specimen. Three different high-risk HPV subtypes and one low-risk HPV subtype (HPV66) were identified in the six CIN1 lesions that progressed.

CONCLUSIONS

There is a significant relationship between p16(INK4a) immunostaining and follow-up (P = .002). p16(INK4a)-negative specimens or positivity in the lower one-third of CIN1 lesions seldom progress to a CIN2-3 lesion.

The clinical impact of using p16(INK4a) immunochemistry in cervical histopathology and cytology: an update of recent developments

Cervical cancer screening test performance has been hampered by either lack of sensitivity of Pap cytology or lack of specificity of Human Papillomavirus (HPV) testing. This uncertainty can lead to unnecessary referral and treatment, which is disturbing for patients and increases costs for health care providers. The identification of p16(INK4a) as a marker for neoplastic transformation of cervical squamous epithelial cells by HPVs allows the identification of HPV-transformed cells in histopathology or cytopathology specimens. Diagnostic studies have demonstrated that the use of p16(INK4a) immunohistochemistry substantially improves the reproducibility and diagnostic accuracy of histopathologic diagnoses. p16(INK4a) cytology has substantially higher sensitivity for detection of cervical precancer in comparison to conventional Pap tests. Compared to HPV DNA tests, immunochemical detection of p16(INK4a) -stained cells demonstrates a significantly improved specificity with remarkably good sensitivity. About 15 years after the initial observation that p16(INK4a) is overexpressed in HPV-transformed cells we review the accumulated clinical evidence suggesting that p16(INK4a) can serve as a useful biomarker in the routine diagnostic work up of patients with HPV infections and associated lesions of the female anogenital tract.

Usefulness of p16/Ki67 immunostaining in the triage of women referred to colposcopy

BACKGROUND

This study compared the performance of p16/Ki67 dual-staining and human papillomavirus (HPV) testing in women referred to colposcopy and sought to determine the usefulness of a morphological evaluation of the double-stained cells.

METHODS

This prospective study included 1123 women (mean age, 35.8 ± 10.9 years) referred to colposcopy from October 2009 to November 2012 due to positive HPV testing or abnormal cytology results (atypical squamous cells of unknown significance, or worse abnormalities). Liquid-based cytology specimens (PreservCyt, Hologic) were used for HPV detection (Hybrid Capture 2 [HC2]; Qiagen) and p16/Ki67 dual-staining (CINtec Plus; Roche-mtm Laboratories). All women underwent histological study. After completion of the study, 18 patients were classified as having cervical cancer (CC), 378 had a high-grade squamous intraepithelial lesion (HSIL), 304 had a low-grade squamous intraepithelial lesion, and 423 were negative.

RESULTS

The sensitivity and specificity of p16/Ki67 dual-staining for HSIL/CC were 90.9% (95% confidence interval [CI] = 87.9-93.9) and 72.1 (95% CI = 68.7-75.4), respectively. For HC2, the figures were, respectively, 96.0% (95% CI = 93.9-98.0) and 41.4 (95% CI = 37.7-45.0). The values were high both in women < 30 and ≥ 30 years old (86.9% and 63.3% versus 92.3% and 77.8%, respectively). The addition of a morphological evaluation of the dual-stain-positive cells with establishment of HSIL features as the threshold for a positive reaction increased the specificity (93.5%) but decreased the sensitivity (84.1%).

CONCLUSIONS

Use of the molecular markers p16 and Ki67 has higher specificity than HC2 tests for HSIL or CC, which may support p16/Ki67 dual-staining use in the triage of patients referred for abnormal screening results. Morphological evaluation of p16/Ki67-positive cells may have some benefits in women younger than 30 years or with low-grade squamous intraepithelial lesion.

ATL

Objective

The p16Ink4a (p16) 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.

Prognostic value of p16-INK4A protein in women with negative or CIN1 histology result: a follow-up study

P16-INK4A overexpression has been proposed as a prognostic marker to manage the follow up of women with positive cytology and/or HPV test but without high-grade cervical intraepithelial neoplasia (CIN2+). This study measures the relative risk (RR) of CIN2+ of p16 positive versus negative in these women. All the women referred to colposcopy from October 2008 to September 2010 with negative or CIN1 colposcopy-guided biopsy were included in the study; women surgically treated or having a CIN2-3 were excluded. All baseline biopsies were dyed with hematoxylin and eosin and p16. Women were followed up according to screening protocols, with cytology or colposcopy at 6 or 12 months. CIN2/3 RRs and 95% confidence intervals (95%CI) were computed. Of 442 eligible women, 369 (83.5%) had at least one follow-up episode. At baseline, 113 (30.6%) were CIN1, 248 (67.2%) negative, and 8 (2.2%) inadequate histology; 293 (79.4%) were p16-negative, 64 (17.3%) p16 positive and 12 (3.2%) not valid. During follow up, we found ten CIN2 and three CIN3; of these, six were p16 positive (sensitivity 46%, 95% CI 19-75). The absolute risk among p16 positives was 9.4/100 compared to 1.7/100 of the p16 negatives (RR 5.5; 95% CI 1.7-17.4). The risk was also higher for CIN1 than for histologically negative women (RR 4.4; 95% CI 1.3-14.3). The RR for p16 in CIN1 did not change (RR 5.2; 95% CI 0.6-47.5). P16 overexpression is a good candidate for modulating follow-up intensity after a negative colposcopy but is limited by its low prospective sensitivity.

Methylation of human papillomavirus-52 and -58 is a candidate biomarker in cervical neoplasia

BACKGROUND

Previous studies of human papillomavirus (HPV)16/18 genome methylation have concluded that methylation status of the L1 gene might act as a biomarker for cervical intraepithelial neoplasia (CIN).

OBJECTIVES

We investigated the correlation between methylation status in the L1 gene and the long control region (LCR) of HPV52/58 and CIN.

STUDY DESIGN

Exfoliated cervical cells were taken from 54 HPV52-positive and 41 HPV58-positive women. The HPV genome was examined using bisulfite modification, polymerase chain reaction amplification, and sequencing.

RESULTS

The CpGs were unmethylated or hypomethylated in the HPV52/58 LCR. In contrast, the methylation status of the HPV52 L1 gene was correlated with the severity of cervical neoplasia, with average percentages of 15%, 34%, and 52% for cervicitis/CIN1, CIN2, and CIN3, respectively (P<0.05). Methylation status of the HPV52 L1 gene was also correlated with the prognosis of CIN1/2, with median percentages of 15% and 35% for regression and persistence/progression, respectively (P<0.05). The methylation status of the HPV58 L1 gene was correlated with the severity of cervical neoplasia, with average percentages of 12%, 38%, and 61% for cervicitis/CIN1, CIN2, and CIN3, respectively (P<0.05).

CONCLUSIONS

The increased methylation at the CpG sites in the HPV52/58 L1 gene was correlated with the severity of cervical neoplasia, similar to HPV16/18 in previous studies. These data suggest that HPV methylation status of the L1 gene is a candidate biomarker of CIN for detecting CIN2 and CIN3.

p16(INK4a) immunohistochemistry is a promising biomarker to predict the outcome of low grade cervical intraepithelial neoplasia: comparison study with HPV genotyping

Objective

In cervical intraepithelial neoplasia (CIN), p16^INK4a immunohistochemistry has been reported to be a useful diagnostic biomarker. However, limited information is available about the association between the p16^INK4a immunohistochemistry and the outcomes of CIN. Here, we report p16^INK4a immunohistochemistry as an effective biomarker to predict the outcomes of CIN.

Methods

p16^INK4a immunohistochemistry was performed in patients with CIN from January 2000 to August 2009. Among these patients, we have performed a retrospective analysis of the medical records to evaluate the outcome of CIN 1-2 and performed statistical analysis to determine the correlation between p16^INK4a expression and the outcomes. We also performed HPV genotyping and analyzed the relation between the infecting human papillomavirus (HPV) genotype and the outcomes.

Results

A total of 244 patients, including 82 with CIN 1, 60 with CIN 2, and 102 with CIN 3, were examined. The rate of p16^INK4a overexpression increased with increasing CIN grade, 20.7% for CIN 1, 80.0% for CIN 2, and 89.2% for CIN 3, with significant differences between CIN 1 and CIN 2-3 group. In the 131 CIN 1-2 patients, the progression rate was significantly higher for the patients showing p16^INK4a overexpression than for those not showing p16^INK4a overexpression (p=0.005); the regression rate was also found to be significantly lower for the patients showing p16^INK4a overexpression (p=0.003). High-risk HPV genotypes were detected in 73 patients (73.7%). Both progression and regression rates were not significantly different between the high-risk HPV-positive and HPV-negative groups (p=0.401 and p=0.381, respectively).

Conclusion

p16^INK4a overexpression was correlated with the outcome of CIN 1-2, and p16^INK4a is considered to be a superior biomarker for predicting the outcome of CIN 1-2 compared with HPV genotyping.

Prognostic value of HPV E6/E7 mRNA assay in women with negative colposcopy or CIN1 histology result: a follow-up study

Pap test, and especially HPV DNA test, identify a large group of women who do not have any clinically relevant lesions, i.e., CIN2+ (Cervical Intraepithelial Neoplasia grade 2 or worse), but who are at greater risk of getting lesions in the future. The follow up of these women needs new biomarkers with prognostic value. The objective of this study is to evaluate the prognostic value of E6/E7 mRNA over-expression assay (PreTect HPV-Proofer, Norchip) for 5 HR-HPV types (16, 18, 31, 33, and 45) for progression to CIN2+ after a negative colposcopy. This prospective study, conducted at four Italian centres, enrolled 673 women with either a negative colposcopy or a negative or CIN1 histology. The clinical end-point was histological confirmation of CIN2+. Women were classified at baseline according to mRNA results and managed according to local colposcopy protocols. At least one conclusive follow-up test was obtained for 347 women (25 months average lapse since recruitment, range 5–74). Only seven CIN2+ were detected during follow up, three among the 82 women positive for mRNA at baseline, two among the 250 negative (Fisher exact test, p = 0.02), and two among the 12 with an invalid test. Absolute CIN2+ risk was 6.7/1,000 person/years in the whole cohort. The absolute CIN2+ risk was 18.4/1,000 person/years and 3.6/1,000 person/years in mRNA-positive and mRNA-negative women, respectively. In conclusion, E6/E7 mRNA over-expression appears to be a good candidate as a prognostic biomarker to manage HR-HPV DNA-positive women with negative colposcopy or histology, particularly in order to decrease follow-up intensity in those who are negative.

Risk of high-grade cervical intraepithelial neoplasia during follow-up in HPV-positive women according to baseline p16-INK4A results: a prospective analysis of a nested substudy of the NTCC randomised controlled trial

BACKGROUND

Immunostaining for p16-INK4A (henceforth p16) is a sensitive and specific method for detection of high-grade cervical intraepithelial neoplasia (CIN) in women infected with human papillomavirus (HPV), but longitudinal data have not been obtained. We investigated the relation between p16 status and risk of CIN during 3 years of follow-up.

METHODS

Women aged 25-60 years were enrolled between June 10, 2003, and Dec 31, 2004, in a multicentre randomised trial comparing HPV testing with cytology. HPV-positive women were referred for colposcopy and, in seven of nine centres, were tested for p16 overexpression by immunostaining. If no CIN was detected, these women were followed up at yearly intervals until clearance of HPV infection. The primary endpoint was histologically confirmed CIN of grade 2 or worse (CIN of grade 2 [CIN2], CIN of grade 3 [CIN3], or invasive cervical cancer) at recruitment or during follow-up. We calculated the absolute and relative risks by p16 status at recruitment. We also calculated the longitudinal sensitivity of p16 testing. Additionally, we assessed the relative sensitivity of an alternative strategy (referral to colposcopy and follow-up of only HPV-positive, p16-positive women) versus conventional cytology in two age groups. Percentages were weighted by the inverse of the tested fraction. The trial in which this study is nested is registered, number ISRCTN81678807.

FINDINGS

Of 1042 HPV-positive women who were tested for p16 with no CIN detected during the first round of screening, 944 (91%) had further HPV tests. 793 (84%) of these 944 were followed up until detection of CIN2 or worse, HPV infection clearance, or for at least 3 years. CIN2 or worse was detected during follow-up in more p16-positive women (31 of 365, 8·8% [95% CI 5·8-11·8]) than in p16-negative women (17 of 579, 3·7% [1·9-5·4]; relative risk [RR] 2·61 [95% CI 1·49-4·59]). RR was higher in women aged 35-60 years at recruitment (3·37 [1·39-8·15]) than in those aged 25-34 years (2·15 [1·00-4·61]), but age was not a significant modifier. CIN3 or worse was detected during follow-up in more p16-positive women (16 of 365, 4·4% [2·3-6·6]) than in p16-negative women (six of 579, 1·3% [0·2-2·3]; RR 3·90 [95% CI 1·57-9·68]). Longitudinal sensitivity of p16 testing for detection of CIN3 or worse during follow-up at all ages was 77·8% (95% CI 63·9-91·6). The relative sensitivity of the alternative strategy compared with conventional cytology was 2·08 (1·13-3·56) in women aged 35-60 years and 2·86 (1·28-5·36) in those aged 25-34 years. HPV-positive, p16-negative women aged 35-60 years had a higher cumulative risk of CIN3 or worse during recruitment or follow-up (2·0%, 95% CI 0·3-3·7) than did HPV-negative women (0·01%, 0-0·04) or those who were cytologically normal (0·04%, 0·02-0·09) at recruitment.

INTERPRETATION

p16 overexpression is a marker for CIN2 or worse or for development of CIN2 or worse within 3 years in HPV-positive women, especially those aged 35-60 years. HPV-positive, p16-positive women need immediate colposcopy and, if the assessment is negative, annual follow-up. Immediate colposcopy can be avoided in HPV-positive, p16-negative women, who can be safely managed with repeat screening after 2-3 year intervals.

FUNDING

European Union; Italian Ministry of Health; Regional Health Administrations of Piemonte, Tuscany, Veneto and Emilia Romagna; and Public Health Agency of Lazio Region.

The Utility of p16INK4a and Ki-67 as a Conjunctive Tool in Uterine Cervical Lesions

Background

Immunohistochemical staining for p16INK4a and Ki-67 has been used to improve the accuracy in making a diagnosis of the uterine cervix cancer on biopsy. This study was conducted to examine the usefulness of these markers in the pathological diagnosis based on cervical biopsy.

Methods

We selected a consecutive series of 111 colposcopically directed cervical punch biopsies. Using these biopsy samples, we performed an immunohistochemical staining for p16INK4a and Ki-67 to establish a diagnosis. The slides were circulated among four pathologists in a sequential order: the hematoxylin and eosin (H&E) slide, H&E slide and p16INK4a-stained slide, and H&E slide, p16INK4a- and Ki-67-stained slides.

Results

The overall rates of the concordance in the first, the second, and the third diagnoses were 77.5%, 82.0%, and 82.0%, respectively. The rate of the concordance in the diagnosis of cervical intraepithelial neoplasm (CIN) 2/3 was increased from 62.2% to 73.0%. But there was a variability in the rate of the revision of the diagnosis between the pathologists. With the application of criteria for interpreting the expressions of p16INK4a and Ki-67, benign and CIN 1 lesions showed a p16INK4a expression score of 0 or 1. But CIN 2 and CIN 3 lesions showed a p16INK4a expression score of 2 and 3, respectively.

Conclusions

The immunostain for p16INK4a and Ki-67 might be useful in reducing an inter-observer variability. But criteria for interpreting both markers should be strictly applied.

Dual stain immunohistochemical localization of p16INK4A and ki-67: a synergistic approach to identify clinically significant cervical mucosal lesions

BACKGROUND

The primary goal of this study was to assess the clinical utility of a multiplexed immunohistochemical method using colocalization of p16 and Ki-67 in identifying high-grade cervical mucosal lesions.

DESIGN

The study included formalin-fixed cervical biopsy specimens, representative of 297 diagnostic regions. They were subjected to 2 colors immunohistochemical staining for p16 and Ki-67 using an EnVision polymer-based method. The chromogens used were of DAB brown for the detection of p16 and alkaline phosphatase blue for Ki-67. Histologic regions were scored positive for either marker based on the detection of p16 or Ki-67 in >10% of the cells of interest.

RESULT

Positive test results with colocalization of p16/Ki-67 were found in 20 of 40 cases of cervical intraepithelial neoplasia 1 (n=40) and in all cases of cervical intraepithelial neoplasia 2/3 (n=32), squamous cell carcinoma (n=11), adenocarcinoma in situ (n=10), and invasive adenocarcinoma (n=8). Colocalization of p16/Ki-67 was also detected in few cells in 1 of 19 sections with tuboendometrial metaplasia but was not detected in normal squamous mucosa (n=78), normal endocervical mucosa (n=76), immature squamous metaplasia (n=13), or in microglandular hyperplasia (n=9).

CONCLUSIONS

The p16 and Ki-67 are coexpressed in virtually 100% of cases of high-grade squamous and glandular lesions, but they are rarely coexpressed in normal tissues or in benign lesions of the squamous and glandular mucosa. Thus, multiplexed colocalization of p16 and Ki-67 is a practical and potentially powerful diagnostic approach to enhance the accuracy of cervical histopathologic diagnosis.

Role of protein biomarkers in the detection of high-grade disease in cervical cancer screening programs

Since the Pap test was introduced in the 1940s, there has been an approximately 70% reduction in the incidence of squamous cell cervical cancers in many developed countries by the application of organized and opportunistic screening programs. The efficacy of the Pap test, however, is hampered by high interobserver variability and high false-negative and false-positive rates. The use of biomarkers has demonstrated the ability to overcome these issues, leading to improved positive predictive value of cervical screening results. In addition, the introduction of HPV primary screening programs will necessitate the use of a follow-up test with high specificity to triage the high number of HPV-positive tests. This paper will focus on protein biomarkers currently available for use in cervical cancer screening, which appear to improve the detection of women at greatest risk for developing cervical cancer, including Ki-67, p16^INK4a, BD ProEx C, and Cytoactiv HPV L1.

Prediction of clinical outcome using p16INK4a immunocytochemical expression in low-grade squamous intraepithelial lesions and high-risk HPV-positive atypical squamous cells of undetermined significance in patients with and without colposcopic evident cervical disease

p16INK4a as a diagnostic marker of a cervical intraepithelial neoplasia of grade 2+ (CIN2+) in atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) cytological samples has been analyzed, but has not yet been included in clinical routine practice. One hundred and ninety-one patients with an abnormal Pap test (84 ASC-US and 107 LSILs) who underwent colposcopy were selected for this study. At enrollment, 96 patients (Group 1) had a positive colposcopy and therefore underwent a cervical biopsy, while 95 (Group 2) had a negative colposcopy and were followed up for up to 1 year. Both groups were tested for p16INK4a using immunocytochemical methods, and the p16INK4a results were correlated with histology or follow-up outcome. In Group 1 ASC-US cases, 82% of lesions less than CIN2 were p16INK4a-negative and all CIN2 cases were p16INK4a-positive (p=0.00044). In Group 1 LSIL cases, 71% of lesions less than CIN2 were p16INK4a-negative and 87% of CIN2/3 were p16INK4a-positive (p=0.00033). Seventy-seven percent of Group 2 ASC-US patients with a negative 1-year follow-up (NF-U) were p16INK4a-negative at enrollment, while all patients with positive follow-up (PF-U) were p16INK4a-positive (p=0.00113). In Group 2 LSIL cases, 83% of patients with NF-U were p16INK4a-negative, while 65% of patients with PF-U were p16INK4a-positive at enrollment (p=0.0014). In fact, 39% of the positive p16INK4a LSIL patients had CIN2+ histological lesions. The positive predictive value of p16INK4a for CIN2+ was 50% in ASC-US and 52% in LSIL cases; the negative predictive value was 100 and 94%, respectively. In conclusion, in our patients, a negative p16INK4a appears to be a marker of the absence of CIN3, while a positive p16INK4a can be correlated with the presence of histological CIN2+ found at enrollment or during the subsequent follow-up. Thus, its clinical predictive value is independent from the colposcopic aspect at enrollment.

Correlation between immunocytochemistry of human papilloma virus L1 capsid protein and behavior of low-grade cervical cytology in Korean women

AIM

The aim of this study was to evaluate the behavior of low-grade squamous intraepithelial lesion (LSIL) in Korean women infected with human papillomavirus (HPV) in relation to the immunocytochemical detection of the HPV L1 capsid protein.

MATERIAL AND METHODS

From January 2006 to December 2007, a total of 353 immunocytochemistry tests were performed on specimens from HPV-infected patients with LSIL. Due to exclusions, the study population was reduced to 318. Subjects were monitored at 4-6 month intervals. The regression, persistence, and progression of the cytologic abnormalities of the 318 cases were compared with the results of HPV L1 capsid protein immunocytochemical detection.

RESULTS

Of the 137 patients negative for the HPV L1 capsid protein, 38 (27.7%) showed progression to high-grade lesions, 50 (36.5%) showed persistence, and 49 (35.8%) showed regression to normal cytological features. In contrast, of the remaining 181 patients positive for the HPV L1 capsid protein, 15 (8.3%) showed progression to high-grade lesions, 74 (40.9%) showed persistence, and 92 (50.8%) showed regression. The results of immunocytochemical testing for the HPV L1 capsid protein show a linear association with the progression or regression behavior of low-grade cervical cytology in patients infected with HPV (linear by linear association test, P<0.05).

CONCLUSION

Immunocytochemical detection of HPV L1 was significantly related with the biological patterns of LSIL in Korean women. Hence, immunocytochemistry for the detection of HPV L1 is beneficial in providing further information for LSIL.

Prognostic Implication of High Risk Human Papillomavirus E6 and E7 mRNA in Patients with Intraepithelial Lesions of the Cervix in Relationship to Age

Since the introduction of the cytological screening programs, a significant reduction in the incidence of cervical cancer has been achieved. Almost all of these cancers are related to high-risk (HR) Human Papillomavirus (HPV) cervical infections. However, the natural history of HPV infection seems to be different in younger patients, resulting in a higher rate of regression. There is, therefore, the need to identify HPV-related biomarkers in order to enhance the effectiveness of screening of high-risk cytological lesions, in particular in women over 35 years of age. This study aims to evaluate the prognostic value of the HR HPV E6 and E7 mRNA expression in women with intraepithelial lesions of the cervix, older or younger than 35 years of age. One hundred and eighty-four HR HPV DNA positive patients with a low squamous intraepithelial lesion (LSIL) were tested for mRNA expressions, included in an observational study, and evaluated at follow-up with standard cytology up to 24 months from the mRNA test. The frequency of HSIL/LSIL cytology in the older cohort of mRNA positive patients was significantly higher compared to mRNA-negative patients, both at 1 and 2 years of follow-up ( Chi-square: p 0.007 and p 0.009), but this difference was not found in the younger cohort. According to our results, the E6/E7 mRNA test could be a biomarker for viral activity, useful in identifying patients at higher risk of abnormal cytology, and in implementing the management of HR HPV DNA-positive women over 35 years of age.

Cervical nitric oxide release and persistence of high-risk human papillomavirus in women

Nitric oxide may serve as one cofactor for human papillomavirus (HPV)-induced development of cervical cancer. Therefore, we first assessed the levels of cervical fluid nitric oxide metabolite (NOx) in 283 women with and without high-risk (hr) HPV. The NOx level in women with hr HPV (48.4 μmol/L [95% CI: 39.4-56.6], n = 199) was higher (p < 0.001) than that in women without hr HPV (24.6 μmol/L [95% CI: 19.1-38.7], n = 84). Second, we evaluated if cervical fluid NOx levels could predict the persistence of hr HPV. Therefore, we followed up 113 women with detectable hr HPV without any treatment for 12 mo and repeated hr HPV test. High-risk HPV persisted in 72 women (64%) and disappeared in 41 women (36%). The median basal levels of NOx were higher (p = 0.02) in women with persistent hr HPV (56.9 μmol/L [95% CI: 48.7-81.0]) compared to those with eradicated hr HPV (37.7 μmol/L [95% CI: 27.0-58.0]). The NOx level higher than the 75th percentile (>87.0 μmol/L) predicted hr HPV persistence (OR = 4.1 [95% CI: 1.3-13.1]). This cutoff level of NOx showed 33% sensitivity and 90% specificity in predicting the persistence of hr HPV, but it failed to predict cytological progression or regression in 12 mo. In conclusion, high cervical fluid NOx appears to be connected to the persistence of hr HPV, but the low predictive capacity of NOx prevents its clinical use at this phase.

MOLECULAR MARKERS OF EARLY CERVICAL NEOPLASIA

Pure morphological distinction of high-grade squamous intraepithelial lesions (HSILs) from their mimics can be challenging. Diagnosis can be difficult with nonconventional HSILs associated with a metaplastic phenotype, squamous intraepithelial lesions (SILs) that defy precise classification such as "eosinophilic dysplasias", and those that overlap with columnar neoplasms, including stratified variants of adenocarcinoma in situ ("SMILE"). Gene expression and protein profiling have identified biomarkers with the potential to decrease diagnostic variability and increase specificity of histological and cytological analysis. Among the ones clinically useful for HSIL detection are p16(INK4A) and MIB-1 which complement each other, differentiating SIL from normal/atrophic (MIB-1 low) or reactive/immature metaplastic (p16(INK4A) scattered) epithelium. Additional markers, including ProEx(TM) C, have been proposed but their added value is yet to be established. In the final analysis, biomarkers are most helpful for distinguishing benign immature or atrophic proliferations from HSIL. The distinction of LSIL from HSIL must be made on the hematoxylin and eosin-stained section and should be made with care, given the potential consequences of a diagnosis of CIN2 or CIN3.

Conjunctive p16INK4a testing significantly increases accuracy in diagnosing high-grade cervical intraepithelial neoplasia

The histopathologic interpretation of cervical intraepithelial neoplasia (CIN) is subject to a high level of interobserver variability and a substantial number of false-positive and false-negative results. We assessed the impact of the conjunctive interpretation of p16(INK4a)-immunostained slides on the accuracy of community-based pathologists in diagnosing high-grade cervical intraepithelial neoplasia (CIN; CIN 2 and CIN 3) in biopsy specimens. Twelve pathologists rendered independent diagnoses on a set of 500 H&E-stained cervical punch and conization specimens. Results were compared with a dichotomized "gold standard" established by consensus of 3 gynecopathology experts. When p16(INK4a)-immunostained slides were added and conjunctively interpreted with the H&E-stained slides, a significant increase in diagnostic accuracy for the detection of high-grade CIN was observed (P = .0004). Sensitivity for high-grade CIN was increased by 13%, cutting the rate of false-negative results in half. Agreement of community-based pathologists in diagnosing high-grade CIN was significantly improved (mean kappa values advanced from 0.566 to 0.749; P < .0001). Reproducibility of p16(INK4a) stain interpretation was excellent (kappa = 0.899). Our results show that conjunctive interpretation of p16(INK4a)-stained slides could significantly improve the routine interpretation of cervical histopathology.

Value of p16(INK4a) as a marker of progression/regression in cervical intraepithelial neoplasia grade 1

OBJECTIVE

The objective of this study was to evaluate the usefulness of p16(INK4a) staining to classify cervical intraepithelial neoplasia grade 1 according to its progression/regression risk.

STUDY DESIGN

Patients with a histologic diagnosis of cervical intraepithelial neoplasia grade 1 were prospectively recruited (n = 138). Simultaneous detection of high-risk human papillomaviruses and p16(INK4a) evaluation were performed. Follow-up was conducted every 6 months by cytology and colposcopy and annually by high-risk human papillomavirus testing, for at least 12 months (mean, 29.0). Progression was defined as a histologic diagnosis of cervical intraepithelial neoplasia grades 2-3, regression as a negative cytology and high-risk human papillomaviruses, and persistence as a cytologic result of low-grade squamous intraepithelial lesions and/or a positive test for high-risk human papillomaviruses.

RESULTS

Progression was observed in 14 women (10.1%), 66 (47.6%) regressed, and 58 (42.0%) had a persistent disease. p16(INK4a) was positive in 77 (55.8%) initial biopsy specimens. Progression to cervical intraepithelial neoplasia grades 2-3 was identified in 14 of 77 (18.2%) women with positive and none of 61 (0.00%) women with negative p16(INK4a) immunostaining (P < .001).

CONCLUSION

p16(INK4a) negative cervical intraepithelial neoplasia grade 1 lesions rarely progress and may benefit from a less intensive follow-up.

RNA (E6 and E7) assays versus DNA (E6 and E7) assays for risk evaluation for women infected with human papillomavirus

In the majority of cases, high-risk human papillomavirus (HR HPV) infections regress spontaneously, with only a small percentage progressing to high-grade lesions. Current screening methods are based on DNA detection. An alternative would be to monitor expression of the E6 and E7 viral oncogenes continuously expressed by malignant phenotypes. In the work reported in this paper, we compared the two methods for a group of women with high-risk HPV infections. Cervical specimens from 400 women, previously found to be HPV DNA positive, were analyzed for HPV DNA by a liquid hybridization assay and typed by multiplex PCR (for types 16, 18, 31, and 33). Identification of HR HPV E6 and E7 RNA transcripts was performed using real-time reverse transcription-PCR and nucleic acid sequence-based amplification assays. Results were compared with concurrent cytological data. HR HPVs were found in 61.2% of patients. The most common genotype was HPV type 16 (HPV-16) (47.1%), followed by HPV-18, HPV-31, and HPV-33. Nine percent of cases involved other genotypes. Among 223 HPV DNA-positive samples, only 118 were positive in the RNA test. Among HPV DNA-positive patients with normal cytology, we detected E6 and E7 RNA transcripts in two cases (18.2%). The rate of detection increased gradually with the grade of the observed lesions, rising from 20% for patients with atypical squamous cells of undetermined significance to 48.1% for women with low-grade squamous intraepithelial lesions and 86.3% for those with high-grade squamous intraepithelial lesions. These results suggest that testing for HPV E6 and E7 transcripts could be a useful tool for screening and patient management, providing more accurate predictions of risk than those obtained by DNA testing.

p16(INK4a) immunostaining in cytological and histological specimens from the uterine cervix: a systematic review and meta-analysis

BACKGROUND

P16(INK4a) is a biomarker for transforming HPV infections that could act as an adjunct to current cytological and histological assessment of cervical smears and biopsies, allowing the identification of those women with ambiguous results that require referral to colposcopy and potentially treatment.

MATERIAL AND METHODS

We conducted a systematic review of all studies that evaluated the use of p16(INK4a) in cytological or histological specimens from the uterine cervix. We also estimated the mean proportion of samples that were positive for p16(INK4a) in cytology and histology, stratified by the grade of the lesion.

RESULTS

Sixty-one studies were included. The proportion of cervical smears overexpressing p16(INK4a) increased with the severity of cytological abnormality. Among normal smears, only 12% (95% CI: 7-17%) were positive for the biomarker compared to 45% of ASCUS and LSIL (95% CI: 35-54% and 37-57%, respectively) and 89% of HSIL smears (95% CI: 84-95%). Similarly, in histology only 2% of normal biopsies (95% CI: 0.4-30%) and 38% of CIN1 (95% CI: 23-53%) showed diffuse staining for p16(INK4a) compared to 68% of CIN2 (95% CI: 44-92%) and 82% of CIN3 (95% CI: 72-92%).

CONCLUSION

Although there is good evidence that p16(INK4a) immunostaining correlates with the severity of cytological/histological abnormalities, the reproducibility is limited due to insufficiently standardized interpretation of the immunostaining. Therefore, a consensus needs to be reached regarding the evaluation of p16(INK4a) staining and the biomarker needs to be assessed in various clinical settings addressing specific clinical questions.