p16INK4Aimmunohistochemical staining and predictive value for progression of cervical intraepithelial neoplasia grade 1: A prospective study in China

Preoperative prediction of p16 expression in cervical cancer by amide proton transfer imaging combined with diffusion kurtosis imaging: a retrospective study

Background

Immunohistochemical p16 expression is important for the assessment of risk factors and prognosis of cervical cancer. This study evaluated the correlation between preoperative amide proton transfer imaging (APT), diffusion kurtosis imaging (DKI), and p16 expression in cervical cancer.

Methods

Fifty-five records of patients with cervical cancer with preoperative magnetic resonance imaging (MRI) and complete postoperative pathology were retrospectively analyzed. Uterine MRI scans were examined, and the corresponding APT values, mean kurtosis (MK), and mean diffusivity (MD) were obtained. Pathology was used to determine p16 positivity. The predictive effects of the APT- and DKI-derived parameters applied alone or in combination with p16 expression were compared.

Results

Among the 55 cases of cervical cancer, 35 were p16 positive and 20 were p16 negative. The receiver operating characteristic curve area (AUC) of p16 was 0.809, 0.801, 0.790, 0.845, 0.866, and 0.871 when APT, MK, and MD were used individually and then jointly. The effect of APT combined with the DKI derivative parameters was more pronounced than when they were used separately.

Conclusion

Preoperative APT and DKI imaging are valuable in predicting the expression of p16 in cervical cancer, and the combination of the two can improve the prediction efficacy. These findings could help to guide treatment decisions and determine prognosis in cervical cancer.

The Role of Predictive and Prognostic Biomarkers in Lower Female Genital Tract Pathology: PD-L1, MMR, HER2, p16, p53, and Beyond

Biomarkers play a crucial role in the diagnosis, treatment planning, and prognosis of premalignant and malignant lesions and are increasingly used in neoplasia of the lower female genital tract (LFGT) including the cervix, vagina, and vulva. This review will discuss key biomarkers routinely used in LFGT pathology, including programmed cell death ligand 1 (PD-L1), mismatch repair (MMR), and tumor mutational burden (TMB) testing, which are FDA-approved companion diagnostics for anti-PD-1 checkpoint inhibitors. Recent developments in HER2 testing as a marker for anti-HER2 therapies, and prognostic biomarkers such as p53 in HPV-independent vulvar intraepithelial lesions and carcinomas, are also reviewed.

Biomarkers differentiating regression from progression among untreated cervical intraepithelial neoplasia grade 2 lesions

BACKGROUND

Cervical intraepithelial neoplasia grade 2 (CIN2) is one of the precursor stages before cervical lesions develop into cervical cancer. The spontaneous development of CIN2 is ambiguous. One part of CIN2 lesions will progress to cervical intraepithelial neoplasia grade 3 or worse (CIN3+), another part will regress to cervical intraepithelial neoplasia grade 1 or less (CIN1-), and the last part will persist. Although the guidelines suggest that CIN2 patients with fertility requirements can be treated conservatively to minimize the risk of infertility and obstetric complications, most CIN2 patients undergo surgical treatment to prevent the progression of the disease, which will lead to over-treatment and unnecessary complications.

AIM OF REVIEW

The clinical outcome of CIN2 lesions is unpredictable and depends on histopathological examinations. Thus, it is necessary to identify the biomarkers differentiating regression lesions from progression lesions, which is conducive to supporting individualised treatment. The natural history of CIN2 is commonly regulated by the interaction of human papillomavirus (HPV) viral factors (HPV genotype and HPV methylation), host factors (p16/Ki-67 status, host gene methylation effects, human leukocyte antigen subtypes and immune microenvironment) and other factors (vaginal microbiota).

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review summarized the biomarkers predicting the spontaneous regression of CIN2, which correlated with HPV infection, the (epi)genetic change of host genes and microenvironment change. However, potential biomarkers must be validated with prospective cohort studies, which should be conducted with expanded enrollment, a longer observational period and the tracking of more patients.

Immunohistochemical markers Ki67 and P16 help predict prognosis in locally advanced cervical cancer

OBJECTIVE

To investigate the relationship between Ki-67 and P16 expression levels after neoadjuvant chemotherapy, and the clinicopathological characteristics and prognosis of patients with locally advanced cervical cancer.

METHODS

Patients with FIGO 2009 stage IB2 or IIA2 cervical cancer, who underwent neoadjuvant chemotherapy combined with radical hysterectomy at the First Affiliated Hospital of Chongqing Medical University between January 2015 and December 2019, were identified retrospectively to correlate postoperative Ki-67 and P16 expression levels with clinicopathological factors. The optimal threshold for predicting recurrence was analysed using receiver operating characteristic (ROC) curves for the Ki-67 index, and univariate and multi-factorial Cox regression analysis were used to investigate the association between clinicpathological features including Ki-67 and P16 and recurrence-free survival.

RESULTS

In total, 334 patients were included after screening. The cut-off value of Ki-67 for determining recurrence was 67.5 % according to the ROC curve. On multi-factorial Cox analysis, lymphatic vascular space (p = 0.003) and Ki-67 index (p = 0.005) were shown to increase the risk of recurrence, and were independent prognostic factors for recurrence, while the expression of P16 was not significantly associated with the risk of recurrence (p = 0.097, odds ratio = 0.319). Patients with cervical cancer in the high Ki-67 expression group (Ki-67 ≥ 67.5 %) had lower recurrence-free survival and overall survival than patients in the low Ki-67 expression group (Ki-67 < 67.5 %) (p = 0.001 and 0.036, respectively).

CONCLUSION

The expression levels of Ki-67 and P16 after neoadjuvant chemotherapy for locally advanced cervical cancer correlated with tumour differentiation. High expression of Ki-67 (Ki-67 ≥ 67.5 %) may indicate poorer recurrence-free survival and overall survival.

Assessment of the relationships between invasive endocervical adenocarcinoma and human papillomavirus infection and distribution characteristics in China: According to the new WHO classification criteria in 2020

OBJECTIVE

To assess the association between endocervical adenocarcinoma (ECA) and HPV (Human papillomavirus) infection, as well as the characteristics of ECA distribution in China.

METHODS

A total of 756 specimens were collected from seven geographic regions across China. All cases were histologically categorized according to the 2020 WHO classification of female genital tract cancers, and 496 cases were included. We performed the SPF10-DEIA-LiPA25 assay on all specimens' whole tissue sections using PCR (WTS-PCR) to detect HPV DNA and 141 WTS-PCR HPV-positive specimens were selected for the laser capture microdissection (LCM).

RESULTS

Four predominant prevalent histological categories of ECA in China were usual type (51.8%, 257), invasive stratified mucin-producing carcinoma (iSMILE) (11.5%, 57), mucinous NOS (not otherwise specid) (10.3%, 51), and gastric type (7.9%, 39). HPV positivity was 91.4% (235/257), 100.0% (57/57), and 90.2% (46/51) in usual type, iSMILE, and mucinous NOS by WTS-PCR detection, respectively (P < 0.001). LCM-PCR results showed a decreasing trend in HPV DNA positivity, and 21 (95.5%) patients with HPV-I were negative for HPV-DNA in glandular epithelial tissue. The most prevalent HPV genotypes in ECA were HPV16 (47.5%), 18 (40.8%), and 52 (6.5%). The average age of patients with HPVA was 44.9 years, while that of patients with HPV-I was 49.1 years, HPVA is more prevalent in younger females in China (P < 0.001).

CONCLUSIONS

In China, the predominant prevalent histological category of ECA is the usual type of adenocarcinoma, followed by iSMILE. Additionally, patients with HPVA tended to be younger than those with HPV-I.

Evaluation of the clinical performance of p16/Ki-67 dual-staining cytology for cervical lesion detection in premenopausal and postmenopausal Chinese women

BACKGROUND

Studies on the clinical performance of p16/Ki-67 dual-staining in detecting cervical lesions by menopausal status were limited.

METHODS

4364 eligible women were enrolled with valid p16/Ki-67, HR-HPV, and LBC test results, including 542 cancer and 217 CIN2/3 cases. The positivity rates of p16 and Ki-67 single staining and p16/ Ki-67 dual-staining were analyzed by different pathological grades and age groups. The sensitivity (SEN), specificity (SPE), positive predictive value (PPV), and negative predictive value (NPV) of each test in different subgroups were calculated and compared.

RESULTS

P16/Ki-67 dual-staining positivity increased with histopathological severity in premenopausal and postmenopausal women (P < 0.05), while no increasing trends of individual expression of p16 single staining and Ki-67 single staining were observed in postmenopausal women. P16/Ki-67 showed higher SPE (88.09% vs. 81.91%, P < 0.001) and PPV (33.8% vs. 13.18%, P < 0.001) in detecting CIN2/3, and higher SEN (89.97% vs. 82.61%, P = 0.012) and SPE (83.22% vs. 79.89%, P = 0.011) in detecting cancer in premenopausal women than postmenopausal women. For triaging the HR-HPV+ population to identify CIN2/3, p16/Ki-67 performed comparably to LBC in the premenopausal women, and showed higher PPV (51.14% vs. 23.08%, P < 0.001) in premenopausal than postmenopausal women. For triaging ASC-US/LSIL population, p16/Ki-67 demonstrated higher SPE and lower colposcopy referral rate than HR-HPV in both premenopausal and postmenopausal women.

CONCLUSIONS

Expressions of p16/Ki-67 dual-staining between premenopausal and postmenopausal women are varied. P16/Ki-67 performs better in detecting cervical lesions in premenopausal women. For triaging, p16/Ki-67 is suitable for HR-HPV+ women, especially premenopausal women, to identify CIN2/3 and women with ASC-US/LSIL.

The Role of p16/Ki-67 Immunostaining, hTERC Amplification and Fibronectin in Predicting Cervical Cancer Progression: A Systematic Review

Human papillomaviruses (HPVs) are common sexually transmitted infectious agents responsible for several anogenital and head and neck cancers. Cervical cancer (CC) is the fourth leading cause of death in women with cancer. The progression of a persistent HPV infection to cancer takes 15-20 years and can be preventable through screening. Cervical cytology (Pap smear) is the standard screening test for CC and precancerous lesions. For ASC-US and ASC-H lesions, a combination of Pap smear and HR-HPV analysis is recommended as a triage step before colposcopy. However, these tests cannot predict progression to CC. For this purpose, we summarized current scientific data on the role of p16/Ki-67 immunohistostaining, telomerase and fibronectin in predicting progression to CC. p16 and p16/Ki-67 dual staining (DS) were more specific than HR-HPV DNA testing for the detection of CIN2+/CIN3+ in women with ASC-US and LSIL. Similarly, hTERC FISH analysis significantly improved the specificity and positive predictive value of HPV DNA testing in differentiating CIN2+ from CIN2 cytological samples. In conclusion, p16 IHC, p16/Ki-67 DS and hTERC FISH amplification are all valid adjunctive biomarkers which significantly increase the sensitivity and specificity of cervical dysplasia diagnosis, especially when combined with HPV DNA testing. However, considering the global socioeconomic background, we can postulate that p16 and p16/ Ki-67 IHC can be used as a next step after positive cytology for ASC-US or LSIL specimens in low-income countries, instead of HPV DNA testing. Alternatively, if HPV DNA testing is covered by insurance, p16 or p16/Ki-67 DS and HPV DNA co-testing can be performed. In middle- and high-income countries, hTERC amplification can be performed as an adjunctive test to HPV DNA testing in women with ASC-US and LSIL.

P16INK4a/ki67 Immunocytochemistry in Improving the Predictive Value for High Grade Cervical Intraepithelial (≥CIN2) Neoplasia in Pap Smear

Introduction:

Cervical cytology has limited sensitivity to detect cervical pre-cancerous lesions. High-risk human papillomavirus (hr-HPV) DNA testing has high sensitivity but its specificity is limited. This study was done to assess the utility of p16^INK4a/ki-67 dual stained cytology in improving the predictive value for high-grade cervical (CIN2+) lesions.

Aim/Objective:

To assess the significance of P16/Ki-67 immunocytochemistry in improving the predictive value for high-grade cervical intraepithelial (≥CIN 2+) lesions on Pap smear.

Material and Methods:

This was a prospective diagnostic study that included 93 patients with ASC-US/LSIL/ASC-H and HSIL on thin prep cervical smears and who also underwent hr-HPV DNA test and colposcopy-guided biopsy. Biopsy was the gold standard against which the performance of P16^INK4a/Ki-67 and hr-HPV results were compared.

Results:

In women of all ages, sensitivity of (96.8%) hr-HPV test and p16/Ki-67 dual immunocytochemistry (≥1 positive cell) were similar and negative predictive value (NPV) was (97.1% vs. 97.9%) but the latter test showed better specificity (69.4% vs. 53.2%) and positive predictive value (PPV, 61.2% vs. 50.8%) for ≥CIN 2 lesions. A higher cut off of at least 10 positive cells gives a higher specificity and PPV, with slightly decreased sensitivity and NPV.

Conclusion:

Because high-risk HPV test has a high sensitivity and NPV, whereas P16/Ki-67 dual immunocytochemistry (≥10 positive cells) has a high specificity and PPV, the latter can be recommended as an ancillary test in hr-HPV-positive women to reduce the number of women going for colposcopy and biopsies.

Hierarchical evaluation of histology and p16-labeling can improve the risk assessment on cervical intraepithelial neoplasia progression

OBJECTIVE

High-grade cervical lesions (HSIL) are associated with the presence of high-risk HPV types, tissue expression of p16, and increased chance of malignant progression, requiring surgical intervention. To improve risk evaluation, we assessed the discriminatory power of the histological findings associated with p16 immunohistochemistry (IHC) staining to classify the low-grade cervical lesion (LSIL) and HSIL.

METHODS

We collected cervical biopsies from colposcopy-visible lesions and non-affected tissue (adjacent to the lesions) of 62 Brazilian women and labeled them with anti-p16 antibodies. In addition to the observational pattern and labeling to define the latent classes (affected vs. non-affected), a computational tool was used for semi-quantitative analysis of p16 expression. The intensity of staining of the nucleus or cytoplasm was captured using the Gimp 2.10 software. ROC curves were used to determine cutoff values for p16 expression in patients classified as LSIL and HSIL by latent class statistics for each labeling stratum.

RESULTS

p16 nuclear labeling showed the best sensitivity and specificity to discriminate LSIL with low p16 expression (62%) and HSIL with high p16 expression (37%). Many patients whose lesions had intermediate levels of p16 nuclear staining were subsequently stratified according to the expression of p16 in the cytoplasm, indicating that five of 21 LSIL were at risk of progression, and 13 of 41 HSIL at risk of regression.

CONCLUSIONS

We suggest a hierarchical analysis, with histology at the first level, followed by a labeling analysis in the nucleus and then in the cytoplasm to increase the accuracy of the HPV cervical lesion stratification.

Prognostic value of HPV 16/18 genotyping and geminin mRNA quantification in low-grade cervical squamous intraepithelial lesion

Low-grade cervical squamous intraepithelial lesion is a precancerous neoplasia that has appreciable probability to evolve into malignancy. To explore the prognostic value of HPV 16/18 genotyping and geminin mRNA quantification in predicting the progressiveness of LSIL. We recruited 212 participants who were negative for intraepithelial lesion or malignancy (NILM 76), low-grade squamous intraepithelial lesion (LSIL 85), high-grade squamous intraepithelial lesion (HSIL 36) and cervical intraepithelial neoplasia grade cervical cancer grade 3, (CIN3 15) patients. Tissues were obtained during excisional treatment. HPV 16/18 genotyping and geminin mRNA qRT-PCR were performed. HPV 16/18 positivity rate and geminin mRNA level were integrated with the clinical parameters into a multivariate logistic model. Area under curve was yielded based on receiver operation curve derived from this multivariate logistic model. Follow-up visits were performed to LSIL patients with progression. HSIL patients have higher HPV 16/18 positivity rate and geminin mRNA levels than LSIL. Among HSIL, CIN3 have higher HPV 16/18 positivity rate and geminin mRNA levels. Multivariate logistic analysis showed that HPV 16/18 positivity and geminin mRNA expression status are independent factors for differentiating HSIL and LSIL. The baseline HPV 16/18 positivity rate and geminin mRNA levels of 18 LSIL patients who developed HSIL are significantly higher than non-progressive LSIL patients. The values examined at follow-up timepoints were also higher than baseline. These results suggest that geminin is implicated in the progression of LSIL and combining HPV 16/18 genotyping and geminin mRNA qRT-PCR could potentially differentiating the progressive LSIL and improve the efficacy of clinical intervention.

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.

Prevalence of high-risk human papillomavirus and cervical lesion risk factors: A population-based study in Zhejiang, China 2010-2019

This study investigates the epidemiological characteristics of high-risk human papillomavirus (hrHPV) and analyzes the risk of cervical lesions among women in Zhejiang province, China. HPV data were collected retrospectively from a cohort of 67 742 women who underwent routine cervical cancer screening from 2010 to 2019. Precancerous and cervical cancer cases (n = 980) were histologically diagnosed as a low-grade squamous intraepithelial lesion (LSIL; n = 341) or a high-grade squamous intraepithelial lesion (HSIL; n = 499) and invasive cervical cancer (ICC) (n = 140) groups. Disordered logistic regression analysis was used to test the relationship between different degrees of cervical lesions, HPV16/18 infection status, positive rate of p16^INK4a (p16), Ki-67 expression, and patient's age in SIL and ICC (270/980 cases) patients. HPV52 (4.7%) was the most prevalent HPV type, followed by HPV16 (3.3%) and HPV58 (2.6%). HPV16 was the most common HPV in SIL, peaking at the age of 30-39. The HPV16 infection rate was significantly higher in HSIL than in LSIL patients; moreover, HPV16, HPV18, and HPV51 infection rates were significantly higher in ICC patients than in HSIL (Bonferroni-adjusted p < 0.0167). The presence of HPV16/18 was also associated with a higher risk of developing HSIL from LSIL (odds ratio [OR] = 9.198, 95% confidence interval [CI]: 2.76-127.49). The increased p16 expression and HPV16/18 were associated with the increased risk of cancer progression (OR = 1.092, 95% CI: 1.03-1.36; OR = 1.495, 95% CI: 1.23-2.19, respectively). The identified hrHPV genotypes in cervical lesions can serve as a baseline indicator for future vaccine assessment in Zhejiang, China.

TOP2A/MCM2, p16INK4a, and cyclin E1 expression in liquid-based cytology: a biomarkers panel for progression risk of cervical premalignant lesions

BACKGROUND

To improve the efficiency of early diagnosis systems for cervical cancer, the use of cellular and viral markers for identifying precancerous lesions with a greater probability to progress to cancer has been proposed. Several cellular proteins and markers of oxidative DNA damage have been suggested as possible biomarkers of cervical carcinogenesis; however, they have not been evaluated together. In this study, we analyzed the expression of the cellular markers p16^INK4a, Ki-67, CyclinE1, TOP2A/MCM2, and telomerase, as well as the DNA oxidative damage markers ROS and 8-OHdG. The analyses were performed in liquid-based cervical cytology samples or biopsies with premalignant lesions or cervical cancer diagnosis, with the purpose of selecting a panel of biomarkers that allow the identification of precursor lesions with greater risk of progression to cervical cancer.

METHODS

We analyzed 1485 liquid-based cytology samples, including 239 non-squamous intraepithelial lesions (NSIL), 901 low-grade squamous intraepithelial lesions (LSIL), 54 high-grade squamous intraepithelial lesions (HSIL), and 291 cervical cancers (CC). The biomarkers were analyzed by immunocytochemistry and Human Papilloma Virus (HPV) genotyping with the INNO-LiPA genotyping Extra kit.

RESULTS

We found that all tested cellular biomarkers were overexpressed in samples with high risk-HPV infection, and the expression levels increased with the severity of the lesion. TOP2A/MCM2 was the best biomarker for discriminating between LSIL and HSIL, followed by p16^INK4a and cyclinE1. Statistical analysis showed that TOP2A/MCM2 provided the largest explanation of HSIL and CC cases (93.8%), followed by p16^INK4a (91%), cyclin E1 (91%), Ki-67 (89.3%), and telomerase (88.9%).

CONCLUSIONS

We propose that the detection of TOP2A/MCM2, p16^INK4a and cyclin E1 expression levels is useful as a panel of biomarkers that allow identification of cervical lesions with a higher risk for progression to CC with high sensitivity and precision; this can be done inexpensively, in a single and non-invasive liquid-based cytology sample.

Analysis of factors affecting the prognosis of patients with cervical intraepithelial neoplasia 2

According to the 2014 World Health Organization Classification of Tumors of Female Reproductive Organs, patients with cervical intraepithelial neoplasia 2 (CIN2) have an equivocal diagnosis, but p16 is considered as the reference index for CIN2. Positive p16 expression in CIN2 is associated with high-grade squamous intraepithelial lesions (HSIL), whereas p16 negative lesions are low-grade squamous intraepithelial lesions. The purpose of the present study was to examine the clinical value of p16 and human papillomavirus (HPV) E6/E7 mRNA in the prognostication of patients with CIN2. From January 2013 to January 2016, 108 patients were diagnosed with CIN2 by biopsy and followed up at 6-month intervals at Peking University People's Hospital (Beijing, China). The expression of HPV E6/E7 mRNA was detected by in situ hybridization, while the expression of p16 and Ki-67 proteins was detected by immunohistochemistry. Of the 108 CIN2 cases, 20 progressed to HSIL/CIN3, 36 cases demonstrated persistence with CIN2 after the follow-up and 52 cases achieved regression (≤CIN1). Of the p16-positive 82 cases, 20 cases were detected to have progressed, whereas in the p16-negative group, no progression was observed. There were statistically significant differences among the p16-positive and negative groups (P<0.05). In the HPV E6/E7 mRNA-positive 69 cases, 18 cases were detected to have progressed, whereas in the HPV E6/E7 mRNA-negative 39 cases, progression was detected in only 2 cases. There were statistically significant differences among the HPV E6/E7 mRNA-positive and negative groups (P<0.05). The area under the receiver operating characteristics curve was plotted; the area under the curve for HPV E6/E7 mRNA was 0.745, that for p16 was 0.546 and that for Ki-67 was 0.501. The detection of HPV E6/E7 mRNA may provide important predictive information for the prognosis of CIN2, however p16 and Ki-67 proteins may provide little value.

The Performance of Immunocytochemistry Staining as Triaging Tests for High-Risk HPV-Positive Women: A 24-Month Prospective Study

It is urgent to develop an accurate approach to improve the predictive performance of hrHPV-based screening. The aim is to evaluate the performance of p16/Ki-67 and p16/MCM2 staining to triage high-risk human papillomavirus- (hrHPV-) positive women. Cervical specimens were collected from eligible women and tested for hrHPV genotyping, cytology, p16/Ki-67, and p16/MCM2 staining at baseline. Women were invited to participate in follow-up screening by cytology and hrHPV testing at 24 months. Positive women received colposcopy and biopsies. Histopathological diagnoses were the gold standard. 485 women came back for the follow-up screening. The positive rate of p16/Ki-67 was 20.2% and of p16/MCM2 was 27.2%. The positive rates of p16/Ki-67 ( P < 0.001) and p16/MCM2 (P=0.021) were increased by the severity of histopathology findings. Among hrHPV-positive women, the sensitivity, specificity, PPV, and NPV for p16/Ki-67 were 90.9%, 67.0%, 16.5%, and 99.0%, and for p16/MCM2 were 81.8%, 43.1%, 9.4%, and 97.1%. The sensitivity of cytology for triaging hrHPV-positive women were lower than p16/Ki-67 (P=0.012) and p16/MCM2 (P=0.065). The cocktail staining did not add sensitivity to p16/Ki-67 or p16/MCM2 staining alone (P > 0.05), however, cutting down the specificity of p16/Ki-67 staining alone with statistical significance (67.0% vs. 40.2%, P < 0.001). The risk of CIN2+ within 24 months for hrHPV-positive but triaging negative women at baseline was 0.5 (0.1-2.7), 0.7 (0.1-4.1), and 2.4 (1.1-5.0) for p16/Ki-67, p16/MCM2, and cytology, respectively. As an objective and accurate immunocytochemical staining, the p16/Ki-67 and p16/MCM2 dual staining performed better than cytology to triage positive hrHPV. On condition that high-quality cytology is unavailable, immunocytochemical staining by p16/Ki-67 or p16/MCM2 is an option for triaging hrHPV-positive women. The combination of p16/Ki-67 and p16/MCM2 could not improve the accuracy in detecting CIN2+.

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.

Performance of HPV Genotyping Combined with p16/Ki-67 in Detection of Cervical Precancer and Cancer Among HPV-Positive Chinese Women

Women with positive high-risk human papillomavirus (hrHPV) need efficient triage testing to determine colposcopy referrals. Triage strategies of combining p16/Ki-67 with extended HPV genotyping were evaluated in this study. In total, 899 women attending cervical cancer screening program and 858 women referred to colposcopy from five hospitals were recruited. All the participants were tested by HPV assays and p16/Ki-67 dual staining. Colposcopy and biopsy were performed on women with any abnormal results. HPV genotypes were divided into four strata (HPV16/18, HPV31/33/58/52, HPV45/59/56/66, and HPV51/39/68/35) according to their risks for cervical intraepithelial neoplasia grade 3 or worse (CIN3+). The positive rates of four genotype strata among CIN3+ women were 3.47% (HPV51/39/68/35), 7.73% (HPV45/59/56/66), 14.7% (HPV31/33/58/52), and 78.1% (HPV16/18), respectively (P _trend < 0.001). The positive rates of p16/Ki-67 increased with the elevation of HPV risk hierarchical from 65.0% in HPV51/39/68/35-positive women to 88.0% in HPV16/18-positive women (P _trend < 0.001). p16/Ki-67 was an effective method for risk stratification of CIN2+ among HPV31/33/58/52- and HPV45/59/56/66-positive women [HPV31/33/58/52: OR for dual stain+ (OR_DS+) of 26.7 (16.8-42.4) and OR for dual stain- (OR_DS-) of 3.87(1.89-7.91); HPV45/59/56/66: OR_DS+ of 10.3(5.05-21.0) and OR_DS- of 1.27(0.38-4.26)]. The combination of HPV16/18 genotyping and p16/Ki-67 triage of HPV31/33/58/52/45/59/56/66-positive women resulted in a lower referral rate (40.1% vs. 41.3%; P < 0.001) as compared with triage of 12 other HPV-positive women with p16/Ki-67, although sensitivity and specificity levels for these two strategies were identical. Combining HPV extended genotyping and p16/Ki-67 can be considered as a promising strategy for cervical cancer screening and triage.

Progression of Precancerous Cervical Lesion Predicted by p16 Protein Immunohistochemistry in Rajavithi Hospital

Objective: To assess the association of p16 immunohistochemical (IHC) staining in cervical squamous intraepithelial lesions (SIL) and progression of cervical intraepithelial neoplasia (CIN) 1 to CIN2+ or recurrence of CIN2+. Material and Methods: A retrospective cohort study of women with newly diagnosed SIL from colposcopy-directed biopsy at Rajavithi Hospital, 2013-2017. Pathologic specimens were reviewed and submitted to p16-IHC staining. Adjusted hazard ratios (HR) of disease-free interval (DFI) and 95% confidence intervals (CI) were carried out using the Cox proportional hazard regression model. Results: A total of 187 women was recruited, 91 cases of positive p16-IHC staining and 96 cases of negative staining. With the median follow-up time of 22 months, women with positive p16-IHC had significantly lower 1-year DFI than those with negative p16-IHC (86.8% vs. 96.6%, p = 0.006). Women with CIN 1 had 22.6% of positive p16-IHC, while those with CIN2-3 had 86.7%. From multivariate analysis, the positive p16-IHC and age > 35 years were the significant prognostic factors of progression/recurrent CIN2+ (adjusted HR 5.33, 95%CI 1.77-16.01, p = 0.003; and adjusted HR 5.80, 95%CI 1.34-25.08, p = 0.019, respectively). From subgroup analysis, the positive p16-IHC was the significant prognostic factor in women with initial CIN1 (HR 5.29, 95%CI 1.18-23.76, p = 0.030), but was not associated with prognosis in women with initial CIN 2-3 (HR 2.13, 95%CI 0.28-16.38, p = 0.468). Conclusion: Overexpression of p16 protein has the prognostic significance of SIL. Using p16-IHC may help stratify patients as low-risk and high-risk groups to progression/recurrence CIN2+.

Evaluation of p16/Ki-67 dual staining in the detection of cervical precancer and cancer in China

Background This study aimed to evaluate the clinical performance of p16/Ki-67 dual staining in the detection of cervical intraepithelial neoplasia grade 2 or 3 or worse (CIN2+/CIN3+) in Chinese women. Methods Cervical exfoliated cells were collected from 537 eligible women and were used for liquid-based cytology (LBC), p16/Ki-67 dual staining, and human papillomavirus (HPV) DNA testing. All women received colposcopy with biopsies taken at abnormal sites. Histopathological diagnoses were used as the gold standard. Results p16/Ki-67 staining had a positivity rate of 43.58% overall; the rate increased significantly with histological severity (p <0.001). The sensitivities of p16/ki-67 for detecting CIN2+ and CIN3+ were 88.10% and 91.30%, respectively. Compared with high-risk HPV (HR-HPV), sensitivity of p16/Ki-67 was lower for detecting CIN2+ (88.10% versus 95.71%), but similar for detecting CIN3+ (91.30% versus 96.27%). Specificities of p16/Ki-67 were 85.02% for detecting CIN2+ and 76.86% for detecting CIN3+, values similar to those for LBC (84.71% for CIN2+, 80.05% for CIN3+) but higher than those for HR-HPV (62.77% for CIN2+, 71.25% for CIN3+). All the tests performed better in women>30 years. With respect to the performance of triage for women with ASC-US, sensitivities of p16/Ki-67 were 86.36% for detecting CIN2+ and 83.33% for detecting CIN3+, values similar to those of HR-HPV. However, specificities of p16/Ki-67 were both higher than those of HR-HPV (85.96% versus 67.54% for CIN2+, 79.84% versus 62.90% for CIN3+). Conclusion P16/Ki-67 dual staining could probably provide an optional method for China's national cervical cancer screening, and could also be considered as an efficient method of triage for managing women with ASC-US.

Human papillomavirus DNA, HPV L1 capsid protein and p16INK4a protein as markers to predict cervical lesion progression

OBJECTIVES

Cervical cancer is the most common malignant tumors in women leading to serious morbidity and mortality worldwide, especially among developing countries. A main cause of the disease is the high-risk human papillomavirus (HR-HPV) infection. HSIL usually progress to cervical cancer, and low-grade lesions, including LSIL and ASCUS, mostly turn to normal or benign lesions, but there are still a small number of patients who will progress to HSIL. Up to now there is no efficient biomarker clinically available to predict people with high risk to progress into HSIL. This study was conducted to evaluate the value of human papillomavirus (HPV) DNA, p16^INK4a protein, and HPV L1 capsid protein in predicting HSIL and minimizing unnecessary colposcopy treatments.

METHODS

1222 patients with HR-HPV infection or with abnormal Thinprep cytologic test (TCT) were chosen to conduct colposcopy in the cervical out-patient clinic of Shanghai First Maternity and Infant Hospital affiliated to Shanghai Tongji University from June 2014 to January 2017. TCT, cervical biopsy, HPV DNA and HPVL1 were performed on all patients. 110 patients were selected to detect p16^INK4a protein. Hybrid capture 2 (HC-2) was used to detect HPV DNA, and their subgroups using gene typing system. Immunohistochemical technology was used to detect HPV L1 and p16.

RESULTS

HPV DNA was positive in 1097 cases, with the positive rate of 89.7% (1097/1222). In particular, the positive expression rates of HPV DNA were 82.3, 95.7, 96.6 and 100% in Normal/CC, LSIL, HSIL and cervical cancer groups, respectively (p < 0.001). HPV L1 was negative in 781 cases with HR-HPV infection, and the overall negative rate is 71.1%. In patients with Normal/CC, LSIL and HSIL, the negative expression rates of HPV L1 were 91.3, 40 and 81.2%, respectively (p value < 0.001). In the 110 patients, HPV L1 was negative in 98.1% (53/54) of Normal/CC, 42.9% (12/28) of LSIL and 85.1% (23/27) of HSIL (p value = 0.0043). P16-positive rates in patients with Normal/CC, LSIL and HSIL were 33.3% (18/54), 75% (21/28) and 96.2% (26/27), respectively (p value < 0.001). 18 out of 28 cases express low positive (+) in LSIL, 25 out of 27 cases express strong positive (3+) in HSIL. Patients with L1(-) p16(+) including 18.5% (10/54) of normal/cervicitis, 60.7% (17/28) of LSIL and 85.1% (23/27) of HSIL (p value < 0.005). Furthermore, patients with L1(-) p16(1+) included 37% (10/27) of normal/cervicitis 59.3% (16/27) of LSIL and 3.7% (1/27) of HSIL; patients with L1(-) p16(2+) consisted of 0% of normal/cervicitis/LSIL and 100% (1/1) of HSIL; patients with L1(-) p16(3+) were composed of 0% of normal/cervicitis, 4.5% (1/22) of LSIL and 95.5% (21/22) of HSIL (p value < 0.005) (Table 6).

CONCLUSION

With the increase in the degree of the cervical lesions, the expression of HPV DNA and p16 is up-regulated while HPV L1 protein is down-regulated. HPV DNA, HPV L1 and p16 are useful markers for the prediction of HSIL. Combined detection of these three markers has important potential to predicting HSIL and minimizing unnecessary colposcope examination.

Biomarker P16 predicts progression risk of anal low-grade squamous intraepithelial lesions

OBJECTIVES

The aim of this study was to determine whether biomarker P16 predicts progression risk for anal low-grade squamous intraepithelial lesions (LSILs).

DESIGN

A retrospective study.

METHODS

One hundred and nine HIV-infected and 18 HIV-uninfected patients with biopsy-proven anal LSIL at initial screening underwent surveillance high-resolution anoscopy and biopsy within 2 years of diagnosis. P16 immunohistochemistry was performed on index lesions and evaluated using a semi-quantitative scoring system. The association of predictors and lesional outcomes (progression, persistence or regression) was analysed using ordinal logistic regression models. A subset of p16-positive LSILs was tested for high-risk human papillomavirus (HR-HPV) DNA using real-time PCR.

RESULTS

Upon follow-up, 46 (36%) LSILs progressed to high-grade squamous intraepithelial lesion (HSIL), 50 (40%) persisted as LSIL and 31 (24%) regressed to benign mucosa (median 16 months, range 5-24 months). Age, sex, race, history of condylomata, CD4 T-cell count and HIV plasma viral load were similar regardless of clinical outcome. P16 immunoreactivity of index lesion was classified as block-positive (n = 36), focal-positive (n = 49) or negative (n = 42). Sixty-four percent of block-positive lesions progressed, as opposed to 35% of focal-positive and 14% of negative lesions (P < 0.001). HR-HPV DNA was detected in 90% of p16 block-positive lesions vs. 55% of focal-positive lesions. In unadjusted analyses, positive p16, HIV and former smoker status were significantly associated with lesional persistence and progression. P16 remained the only significant predictor in an adjusted model.

CONCLUSION

Biomarker p16 is the strongest predictor for anal LSIL-to-HSIL progression, outperforming other risk factors. To enhance the overall effectiveness of surveillance, we propose using p16 immunohistochemistry to help stratify patients at high vs. low risk of progression.

p16 immunostaining in histological grading of anal squamous intraepithelial lesions: a systematic review and meta-analysis

p16 is the most widely studied biomarker in lower anogenital tract squamous intraepithelial lesions and, currently the only recommended biomarker for histological grade assessment. The aim of this systematic review and meta-analysis was to evaluate p16-positive rates according to anal squamous intraepithelial lesions/anal intraepithelial neoplasia (AIN) grade. Two investigators independently searched four electronic databases: PubMed, Web of Sciences, Scopus, and Embase from inception until August 2017. Studies that evaluated p16 immunostaining in histological samples of anal and/or perianal squamous intraepithelial lesions and defined a p16-positive result as diffuse block staining with nuclear or nuclear plus cytoplasmic staining were included. A meta-analysis was performed using a random effects model. Fifteen studies consisting of 790 samples were included. The proportion of p16 expression increased with the severity of histological grade. p16 positivity was 2% (95% CI: 0.2-5%) in normal histology, 12% (95% CI: 2-27%) in low-grade squamous intraepithelial lesions (LSILs)/AIN1 (excluding condylomas), 7% (95% CI: 2-13%) in all LSIL (AIN1/LSIL/condyloma), 76% (95% CI: 61-88%) in AIN2, and 90% (95% CI: 82-95%) in AIN3. For anal high-grade squamous intraepithelial lesions (HSILs), in studies using a two-tiered nomenclature, p16 positivity was 84% (95% CI: 66-96%) and for all HSIL (AIN2, AIN3, HSIL combined) it was 82% (95% CI: 72-91%). In summary, p16 positivity in anal squamous intraepithelial lesions appears to be in a similar range to the commonly described cervical squamous intraepithelial lesions, however, for anal low-grade lesions positivity seems to be lower.

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.

Evaluation of p16/Ki-67 dual staining in detection of cervical precancer and cancers: a multicenter study in China

Purpose

To analyze the clinical performance of p16/Ki-67 dual-stained cytology identifying high-grade cervical intraepithelial neoplasia (CIN2+) in Chinese women.

Methods

1079 women attending ongoing cervical cancer screening and 211 “enriched” women aged ≥30yrs with biopsy-confirmed CIN2+ from five Chinese hospitals were enrolled during year 2014-2015. Cervical specimens were collected for high-risk human papillomavirus (HR-HPV) DNA analysis, Liquid-based cytology (LBC) and p16/Ki-67 dual staining. Colposcopy and biopsy were performed on women with any abnormal result.

Results

p16/Ki-67 positivity increased with histologic severity. It was 18.4%(183/996) in normal histology, 54.0%(34/63) in CIN1, 81.0%(34/42) in CIN2, 93.3%(111/119) in CIN3, 71.4% (5/7) in adenocarcinoma and 95.2%(60/63) in squamous cell carcinoma. Compared with the HR-HPV negatives, p16/Ki-67 expression was significantly higher in the HPV16/18 positive (OR: 35.45(95%CI: 23.35-53.84)) and other 12 HR-HPV types positive group (OR: 8.01(95%CI: 5.81-11.05). The sensitivity and specificity of p16/Ki-67 to detect CIN2+ in the entire population were 90.9% and 79.5%, respectively. In women with ASC-US and LSIL, sensitivity and specificity for detection of CIN2+ were 87.5% and 66.4%, respectively, with a referral rate of 43.8%. In women who tested positive for HR-HPV, sensitivity and specificity of dual-staining for detection of CIN2+ were 92.7% and 52.7%, respectively, and the referral rate was 68.7%.

Conclusions

p16/Ki-67 dual-stained cytology provided a high sensitivity and moderate specificity to detect underlying cervical precancer and cancers in various settings, and might be considered as an efficient screening tool in China.

Prognostic value of human papillomavirus 16/18 genotyping in low-grade cervical lesions preceded by mildly abnormal cytology

Histological low-grade squamous intraepithelial lesion/cervical intraepithelial neoplasia grade 1 (LSIL/CIN1) preceded by normal or mildly abnormal cytology is recommended for conservative follow-up, with no separated management. In this study, we assessed the triage value of human papillomavirus (HPV) 16/18 genotyping in 273 patients with LSIL/CIN1. HPV16/18 genotyping was performed at baseline and follow-up was at 6-monthly intervals for up to 2 years. At each follow-up, women positive for cytology or high-risk HPV (hrHPV) were referred for colposcopy. Enrollment cytology, HPV16/18 genotyping, and questionnaire-obtained factors were linked to the 2-year cumulative progression rate. Univariate and multivariate analyses were performed taking into account time-to-event with Cox proportional hazard regression. The results showed that 190 cases (69.6%) regressed, 37 (13.6%) persisted, and 46 (16.8%) progressed. HPV16/18 positivity (hazard ratio (HR), 2.708; 95% confidence interval (CI), 1.432-5.121; P=0.002) is significantly associated with higher 2-year cumulative progression rate. Sub-analysis by enrollment cytology and age restricted the positive association among patients preceded by mildly abnormal cytology and aged 30 years or older. Immediate treatment is a rational recommendation for the high-risk subgroup, when good compliance is not assured.

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.

Influence of Human Papillomavirus Infection on the Natural History of Cervical Intraepithelial Neoplasia 1: A Meta-Analysis

Objective

To provide a scientific basis for the prevention and treatment of cervical intraepithelial neoplasia grade 1 (CIN1). This study evaluated the impact of human papillomavirus (HPV) infection on the natural history of CIN1.

Methods

Electronic databases of Cochrane Library, EMBASE, PubMed, CNKI, CBM, and Wanfang were searched in April 2016. The eligibility criteria were documented by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We used the Newcastle-Ottawa scale (NOS) to assess study quality.

Results

Thirty-eight studies out of 3,246 identified papers were eligible for inclusion. The risk of CIN1 progression (relative risk [RR]: 3.04; 95% confidence interval [CI]: 2.41–3.83; P < 0.00001) and persistence (RR: 1.48; 95% CI: 1.17–1.87; P = 0.001) was higher in the HPV-positive group than HPV-negative group. Specifically, the risk of CIN1 progression (RR: 13.91; 95% CI: 3.46–55.90; P = 0.000) was higher among persistent high-risk HPV-positive patients and the ratio of CIN1 regression (RR: 0.65; 95% CI: 0.59–0.71; P < 0.00001) was lower in the HPV-positive group than HPV-negative group.

Conclusion

HPV infection resulted in an increased risk of CIN1 progression and decreased disease reversibility. Persistent high-risk HPV infection resulted in a further increased risk of CIN1 progression.

[Self-evaluation of conization indications since the introduction of the French colposcopy and cervico-vaginal pathology quality charter in 2 colposcopy centers]

OBJECTIVES

Analyze the efficiency of the implementation of the colposcopy and cervico-vaginal pathology quality charter. The question was to determine whether the criteria of more than 70% of excisional conizations containing CIN2+ lesions (cervical intraepithelial neoplasia 2 or 3 or carcinoma in situ) had been reached and demonstrate a reduction of the conization rate is possible.

METHODS

An epidemiological descriptive, retrospective and multicenter study was performed in "Nord Franche-Comté Hospitals" (Belfort and Montbéliard, France) during the period from November 2013 to January 2015. Inclusion criteria were patients over 25 years undergoing cervical excisions for diagnostic and/or therapeutic purposes after Pap smear screening followed by colposcopically directed biopsies. The files were selected from a data collection and studied using the computerized patient record.

RESULTS

In total, 116 conizations were performed: 103 by four French Society of Colposcopy and Cervico-Vaginal Pathology (SFCPCV) members and 13 by four SFCPCV non-members. The overall result of the primary outcome showed 53% of CIN2+ lesions found in cervical conization specimens, which can be broken down to 55% for the group of SFCPCV members and to 38% for the group of SFCPCV non-members. The statistical analysis indicates a significant difference (P=0.02) in the percentage of CIN2+ lesions discovered on the surgical specimen for the group of SFCPCV members.

CONCLUSIONS

This self-evaluation shows that it is essential to be a SFCPCV member and to adhere to the charter. By complying with the charter and associating the new National Cancer Institute recommendations (December 2016), it is possible to reduce the conization rate and even to surpass the target of more than 70% of excisional conizations containing CIN2+ lesions.

Deciphering the Multifactorial Susceptibility of Mucosal Junction Cells to HPV Infection and Related Carcinogenesis

Human papillomavirus (HPV)-induced neoplasms have long been considered to originate from viral infection of the basal cell layer of the squamous mucosa. However, this paradigm has been recently undermined by accumulating data supporting the critical role of a discrete population of squamo-columnar (SC) junction cells in the pathogenesis of cervical (pre)cancers. The present review summarizes the current knowledge on junctional cells, discusses their high vulnerability to HPV infection, and stresses the potential clinical/translational value of the novel dualistic model of HPV-related carcinogenesis.

Usefulness of p16INK4a staining for managing histological high-grade squamous intraepithelial cervical lesions

p16^INK4a (p16) tumor-suppressor protein is a biomarker of human papillomavirus (HPV) oncogenic activity that has revealed a high rate of positivity in histological high-gade squamous intraepithelial lesion/cervical intraepithelial neoplasia grade 2 (HSIL/CIN2) lesions. However, there is a paucity of data regarding p16 status as a surrogate marker of HSIL/CIN2 evolution. The aim of this study was to evaluate the outcome of HSIL/CIN2 patients followed up without treatment for 12 months according to p16 immunohistochemical staining. Patients diagnosed with HSIL/CIN2 colposcopy-directed biopsy, were recruited prospectively between December 2011 and October 2013. p16 staining was performed in all HSIL/CIN2 diagnostic biopsies. Follow-up was conducted every 4 months by cytology, colposcopy and biopsy if suspicion of progression and once the 12 months of follow-up completed. Complete regression, partial regression, persistence, and progression rates of HSIL/CIN2 were defined as a final outcome. A total of 96 patients were included in the analysis. The rate of spontaneous regression was 64%, while 28% had persistent disease, and 8% progressed at 12 months of follow-up. p16 was positive in 81 (84%) initial HSIL/CIN2 biopsies. Regression was observed in all 15 p16 negative cases and in 46 of 81 (57%) p16 positive cases (P=0.001). In conclusion, patients with p16 negative HSIL/CIN2 biopsy had a high rate of regression during first 12 months of follow-up. Status of p16 staining could be considered for HSIL/CIN2 management.

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.

Aberrant Expression of the Cell Polarity Regulator aPKCλ/ι is Associated With Disease Progression in Cervical Intraepithelial Neoplasia (CIN): A Possible Marker for Predicting CIN Prognosis

Atypical protein kinase C λ/ι (aPKCλ/ι) is a regulator of epithelial cellular polarity. It is also overexpressed in several cancers and functions in cell proliferation and invasion. Therefore, we hypothesized that aPKCλ/ι may be involved in development and progression of cervical intraepithelial neoplasia (CIN), the precancerous disease of cervical cancer induced by human papillomavirus. To do this, we investigated the relationship between aPKCλ/ι expression and CIN. aPKCλ/ι expression level and subcellular localization were assessed in 192 CIN biopsy samples and 13 normal epithelial samples using immunohistochemistry. aPKCλ/ι overexpression (normal epithelium, 7.7%; CIN1, 41.7%; CIN2/3, 76.4%) and aPKCλ/ι nuclear localization (normal epithelium, 0.0%; CIN1, 36.9%; CIN2/3, 78.7%) were higher in CIN samples than normal samples (P<0.05), suggesting that CIN grade is related to aPKCλ/ι overexpression and nuclear localization. Then, 140 CIN cases were retrospectively analyzed for 4-yr cumulative disease progression and regression rates using the Cox proportional hazards model. CIN1 cases with aPKCλ/ι overexpression or aPKCλ/ι nuclear localization had a higher progression rate than CIN1 cases with normal aPKCλ/ι expression levels or cytoplasmic localization (62.5% vs. 9.7% and 63.1% vs. 9.4%, respectively; P<0.001). Multivariate analysis indicated that human papillomavirus types 16 and 18, aPKCλ/ι overexpression (hazard ratio=4.26; 95% confidence interval, 1.50-12.1; P=0.007), and aPKCλ/ι nuclear localization (hazard ratio=3.59; 95% confidence interval, 1.24-10.4; P=0.019) were independent risk factors for CIN1 progression. In conclusion, aPKCλ/ι could be useful for the therapeutic management of patients with CIN, particularly those with non-human papillomavirus 16/18 types.

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.

Management of HPV-related cervical disease: role of p16INK4a immunochemistry. Review of the literature

This systematic review of 43 studies aims to evaluate the absolute and relative sensitivity and specificity of p16INK4a with regard to uterine cervix lesions, describing innovations and techniques for the detection of high-grade cervical dysplasia and allowing correct treatment. Studies were identified in the PubMed database up to March 2015. The keywords hrHPV, p16INK4a gene, and uterine cervical disease (MeSH terms) were used. Only English-language articles were included. We considered retrospective and prospective studies that assessed p16INK4a or p16INK4a/Ki67 staining, with or without HPV-DNA testing (HC2/PCR) as a comparator test, in cytological/histological specimens for which the diagnosis of ASCUS, LSIL or HSIL was verified with a reference standard. The primary outcome for cervical lesions was evaluation of the absolute p16INK4a immunoreactivity; the secondary outcome was evaluation of the relative p16INK4a immunoreactivity versus HPV testing in those studies where comparator tests were available. p16INK4a was more specific than HPV-DNA test (median values of 56.1% vs. 52.25% in CIN grade ≥2 lesions; 82.5% vs. 53% in negative and CIN grade ≥1 lesions). The main limitation of this study is linked to both qualitative and quantitative p16INK4a levels of expression, while the second limitation is the lack of standardized scales. p16INK4a and HPV-DNA used together increased the sensitivity and negative predictive value for CIN detection. p16INK4a can be considered a biomarker of CIN2 or CIN3, indicating a high risk of relapse or evolution to invasive carcinoma. Also p16INK4a-negative CIN should be considered and further research should be performed.

p16 Immunohistochemistry Interpretation by Nonpathologists as an Accurate Method for Diagnosing Cervical Precancer and Cancer

OBJECTIVE

We conducted a pilot study of whether nonpathologists could accurately diagnose cervical precancer in biopsies using only a basic light microscope, evaluating p16 immunohistochemistry (p16 IHC) of biopsies, and video-based training for both.

MATERIALS AND METHODS

Using biopsies collected as part of a screening study conducted in rural China, we randomly selected 50 biopsies with a precancerous diagnosis of cervical intraepithelial neoplasia grade 2 (CIN2) or more severe (CIN2+) and 50 biopsies with diagnosis of CIN less severe than CIN2, and stained them for p16 using a commercial IHC kit. Twelve nonpathologists of varying educational backgrounds living in Beijing, China received video training and were assigned one of 4 sets of 25 CIN2+ and 25 CIN less severe than CIN2 for evaluation. A pathologist reviewed all 100 cases.

RESULTS

The mean sensitivity and specificity of the p16 IHC staining scored by the nonpathologists were 91.7% and 94.1%, respectively, compared to scoring by the pathologist. The readers and the pathologist agreed on p16 IHC scoring for 42 (84%) of the 50 slides of CIN less severe than CIN2 and 37 (74%) of the 50 CIN2+ slides. The mean sensitivity and specificity for consensus CIN2+ of p16 IHC as scored by the readers were 88% and 87%, respectively, versus an overall sensitivity and specificity by the pathologist of 96% and 92%, respectively.

CONCLUSIONS

We demonstrated that nonpathologists can accurately diagnose CIN2+ using p16 IHC alone.

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.

Investigating Diagnostic Problems of CIN1 and CIN2 Associated With High-risk HPV by Combining the Novel Molecular Biomarker PanHPVE4 With P16INK4a

Grading cervical intraepithelial neoplasia (CIN) determines clinical management of women after abnormal cytology with potential for overdiagnosis and overtreatment. We studied a novel biomarker of human papillomavirus (HPV) life-cycle completion (panHPVE4), in combination with the minichromosome maintenance (MCM) protein cell-cycle marker and the p16INK4a transformation marker, to improve CIN diagnosis and categorization. Scoring these biomarkers alongside CIN grading by 3 pathologists was performed on 114 cervical specimens with high-risk (HR) HPV. Interobserver agreement for histopathology was moderate (κ=0.43 for CIN1/negative, 0.54 for CIN2/≤CIN1, and 0.36 for CIN3). Agreement was good or excellent for biomarker scoring (E4: κ=0.896; 95% confidence interval [CI]: 0.763-0.969; p16INK4a : κ=0.798; 95% CI: 0.712-0.884; MCM: κ=0.894; 95% CI: NC (this quantity cannot be calculated). Biomarker expression was studied by immunofluorescence and immunohistochemistry and was correlated with 104 final CIN diagnoses after histologic review. All 25 histologically negative specimens were p16INK4a and panHPVE4 negative, although 9 were MCM-positive. There were variable extents of p16INK4a positivity in 11/11 CIN1 and extensive panHPVE4 staining in 9/11. Ten CIN2 lesions expressed panHPVE4 and p16INK4a, and 13 CIN2 expressed only p16INK4a. CIN3 showed extensive p16INK4a positivity with no/minimal panHPVE4 staining. PanHPVE4, unlike MCM, distinguished CIN1 from negative. PanHPVE4 with p16INK4a separated CIN2/3 showing only expression of p16INK4a, indicating transforming HR-HPV E7 expression, from CIN1/2 showing completion of HR-HPV life cycle by E4 expression and variable p16INK4a expression. PanHPVE4 and p16INK4a staining are complementary markers that could provide simple, reliable support for diagnosing CIN. Their value in distinguishing CIN1/2 that supports HR-HPV life-cycle completion (and which might ultimately regress) from purely transforming CIN2/3 needing treatment warrants further research.

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.

Risk stratification by p16 immunostaining of CIN1 biopsies: a retrospective study of patients from the quadrivalent HPV vaccine trials

Previous studies of p16 immunohistochemistry (IHC) on CIN1 have suggested the likely utility of p16 in stratification of women at risk for subsequent CIN2/3. But those studies had limitations in statistical power, histologic diagnosis, and disease ascertainment. We conducted a retrospective study of p16 IHC on adjudicated CIN1 tissue diagnosed in young women participating in the placebo arm of the quadrivalent human papillomavirus (HPV) vaccine trials. Tissue sections were stained with p16 IHC and hematoxylin and eosin. p16 IHC was scored using LAST criteria, and hematoxylin and eosin-stained sections were reviewed for concordance with the adjudicated diagnosis. p16 IHC, antecedent high-grade cytology, review diagnosis, and HPV16 detection were assessed as independent risk factors for subsequent CIN2/3. Five hundred twenty-four patients with CIN1 biopsies and complete data were identified, 63 (12.0%) of whom developed CIN2/3 in follow-up. p16 positivity (P=0.06), review diagnosis of CIN2/3 (P=0.04), HPV16 positivity (P=0.01), and antecedent high-grade cytology (P=0.02) were (marginally) associated with CIN2/3. In a logistic regression model, the associations with CIN2/3 (vs. other), expressed as odds ratios (95% confidence intervals), were 1.6 (0.91-2.8) for p16, 2.0 (1.0-3.7) for HPV16, and 2.2 (1.1-2.4) for antecedent high-grade cytology. The mean risks for CIN2/3 estimated from the model ranged from 7.6% for negative for all markers to 36.3% for positive for all 3 markers. p16 IHC does not risk stratify CIN1 patients in a manner that would alter recommended management for CIN1. This reinforces the LAST recommendations that p16 should only be used selectively for problematic scenarios, such as CIN2 because of its inherent lack of reproducibility, cases in which one is struggling between CIN1 and CIN2, and benign mimics of CIN3.

p16 expression in patients with cervical cancer and its prognostic significance: meta-analysis of published literature

OBJECTIVES

p16, a tumour suppressor, is unable to express its suppressive effects following interaction with E7-retinoblastoma protein. Previous reports have suggested that p16 immunostaining allows precise identification of cervical intra-epithelial neoplasia and cervical cancer lesions in biopsies. The prognostic value of p16 expression in cervical cancers has been evaluated for several years, but the results remain controversial. As such, the authors undertook a systematic review and meta-analysis of studies assessing the impact of p16 expression on overall survival and disease-free survival.

STUDY DESIGN

Medline, Embase and China National Knowledge Infrastructures were searched to identify studies on the prognostic impact of p16 expression in patients with cervical cancer. In total, 1070 patients from 10 eligible studies were included in the analysis. Pooled risk ratios (RRs) with 95% confidence intervals (95% CI) were calculated.

RESULTS

A significant association was found between p16 expression and increased disease-free survival (RR 0.60; 95% CI 0.44-0.82; p=0.001). However, no significant association was found between p16 and overall survival.

CONCLUSION

p16 expression may be predictive of a favourable prognosis in patients with cervical cancer. However, large-scale, multicentre and well-matched cohort studies are warranted to confirm this finding.

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.

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.

p16 INK4a and Ki67 expression in normal, dysplastic and neoplastic uterine cervical epithelium and human papillomavirus (HPV) infection

Cellular cycle proteins like the p16(INK4a) and the Ki67 proliferation nuclear antigen have been used as oncogenicity cellular markers. The E6 and E7 oncoproteins interact with tumor suppressor genes p53 and pRb, culminating with the p16(INK4a) overexpression. The objective of this study was to evaluate the presence of HPV-DNA in 174 cervical biopsies and correlate the different histological grades with the p16(INK4a) and Ki67 immunohistochemical expression (IHC). A cross-sectional study that enrolled a total of 174 women who underwent uterine cervical biopsies between February 2003 and December 2006, in southern Brazil, was performed. Cervical smear samples were analyzed for the presence of HPV-DNA through polymerase chain reaction (PCR), and biopsy samples were examined for p16(INK4A) and Ki67 expression through IHC techniques. The presence of HPV-DNA was observed in 89% of the tested patients, among which 52% were positive for high-risk (HR) viral types [16, 18 and 31]. Regarding p16(INK4a), an expression of 69% was observed, being expressed in 100% of the high-grade squamous lesions (HSIL) and HR-HPV-DNA positives. Ki67 expression was associated with the lesion grade, being more expressive in the most severe lesions (p<0.001). p16(INK4A) and Ki67 markers coexpression was present in 86% of the samples (p<0.001), being 100% among those positive to HR-HPV-DNA with HSIL (p<0.001). The results suggest an association between the presence of HR-HPV infection and the p16(INK4a) and Ki67 expression and which is even stronger among women with HSIL.