Diagnosing Cervical Biopsies in Adolescents

[Modern biomarkers for precancerous lesions of the uterine cervix : Histological-cytological correlation and use]

The correlation between the cytological findings from the PAP smear and the histological outcome in cases where the cytological findings must be histologically verified, is an integral component of the German screening program for cervical cancer. These data are collected nationwide as part of a benchmarking process by the individual Associations of Statutory Health Insurance Physicians (KV) in the federal states and reported to the National Association of Statutory Health Insurance Physicians (KBV) in Berlin. In most cases there is a good correlation between cytology and histology but in some cases either a different grade of severity of cervical intraepithelial neoplasia (CIN) is found or the histological findings are negative. The reasons for a lack of correlation can be insufficient sampling in the cytology or the biopsy or a misinterpretation of the individual findings. Although the findings from H&E sections are considered to be the gold standard in the histological evaluation, it has long been known that the interobserver agreement in these preparations is only moderate. A significant improvement becomes apparent, firstly by the classification of cervical cancer precursors into low-grade and high-grade groups and secondly by the targeted application of biomarkers, in particular p16 and Ki-67, according to the recommendations of the lower anogenital squamous terminology standardization (LAST) project. The biomarkers p16 and Ki-67 should be used in the differential diagnostics between reactive and reparative alterations and for further differentiation of a CIN grade 2 but not to confirm a CIN grade 3. It is still unclear whether p16 is suitable as a prognostic marker for low-grade lesions.

p16 Staining of Cervical Biopsies May Decrease the Frequency of Unnecessary Loop Electrosurgical Excision Procedures

OBJECTIVE

Loop electrosurgical excision procedures (LEEPs) are negative for high-grade cervical intraepithelial neoplasia (CIN 2+) after a hematoxylin and eosin-based CIN 2+ colposcopic biopsy diagnosis in 14% to 24% of cases. This may be due to diagnostic errors or biopsy-related regression of the dysplasia. Because p16 immunohistochemical staining of cervical biopsies improves diagnostic accuracy, we hypothesized that p16-based cervical biopsy diagnoses may reduce the frequency of negative LEEPs.

MATERIALS AND METHODS

We performed a retrospective cross-sectional study of all cervical LEEPs completed at our institution from 2002 to 2012. We recorded patient age, sexual history, smoking history, pathologic diagnoses (including whether the diagnosis was p16 based), the number of days from biopsy to follow-up LEEP, and clinical follow-up. This yielded 593 study subjects meeting inclusion criteria of CIN 2+ colposcopic diagnoses with follow-up LEEP and 2 years of clinical follow-up. Colposcopic biopsies and follow-up LEEPs were reviewed and p16 immunostaining was performed on all samples to provide criterion standard results. Data were analyzed by χ and regression modeling.

RESULTS

Our practice employed p16 to aid cervical biopsy diagnoses by 2006. The frequency of negative LEEPs before 2006 was 12 (10%) of 126. The frequency dropped during the p16 era (2006-2012) to 23 (5%) of 467. Overall, we observed an inverse relationship between the frequency of p16 employment and the frequency of negative LEEP outcomes (R = 0.71; p < .001), independent of potential covariates.

CONCLUSIONS

Our data suggest that more accurate p16-based diagnoses may reduce the frequency of unnecessary LEEPs.

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 Immunohistochemistry is useful in confirming high-grade squamous intraepithelial lesions (HSIL) in women with negative HPV testing

SUMMARY

It is believed that almost all squamous cell carcinomas of the cervix are associated with HR-HPV infection. However, a subset of high-grade squamous intraepithelial lesion (HSIL) (CIN2 and CIN3) lesions is found in those women with negative HPV testing. Knowledge of HPV status can influence pathologists' decision in rendering the diagnosis of cervical squamous intraepithelial lesions (SIL). p16, a surrogate marker for HSIL, has been widely applied to facilitate accurate diagnosis of HPV-related cervical dysplasia, especially CIN2 and CIN3. To assess whether p16 immunostaining is useful in diagnosing HSIL in women with negative HPV testing, we studied the utility of p16 immunohistochemistry in 46 women of HSIL and HPV-negative status. A total of 46 cases of initial biopsies with histopathologically diagnosed HSIL (CIN2 and CIN3) were identified from our hospital archives. All women were HPV negative with at least 1 HPV testing using HC-II (Qiagen) within 6 mo of initial biopsy. LEEP procedures within 6 mo of initial biopsies were reviewed and documented. Immunohistochemical staining of p16 was performed on recuts of all original biopsies. Some LEEP specimens without evidence of HSIL (CIN2 and CIN3) on hematoxylin and eosin had recuts with deeper levels and p16 immunostaining to confirm the negative diagnosis. p16 immunostaining were evaluated as negative, focal/patchy, or diffuse staining pattern. Patients' HPV testing status and related clinicopathologic information were reviewed, tabulated, and correlated with p16 immunostaining patterns. Forty-six women between the age of 17 and 58 yr, with a median of 35 yr, were all HPV-negative. All women, except 2, had an abnormal cytologic interpretation at the time of HPV testing ranging from ASC-US to HSIL. Forty-two women (91.3%) had LEEP procedures done within 6 mo of the initial biopsies. LEEP specimens showed that 76.2% (32 cases) women had HSIL, including 22 cases of CIN2 and 10 cases of CIN3, 14.3% (6 cases) had low-grade squamous intraepithelial lesion (CIN1), and 9.5% (4 cases) had benign cervix. p16 immunostaining, performed on initial biopsies with histopathologic diagnoses of CIN2 or CIN3, showed that 66.7% (28 cases) had diffuse staining pattern, 16.7% (7 cases) had focal/patchy pattern, and 16.7% (7 cases) had negative p16 staining. On LEEP follow-up, all 28 cases with diffuse p16 staining pattern had HSIL (CIN2 and CIN3), and all 7 cases with negative p16 staining had no detectable high-grade dysplasia. For those 7 cases with focal/patch p16 staining pattern, 4 had HSIL (CIN2) and 3 had low-grade squamous intraepithelial lesion (CIN1) on LEEP follow-up. Approximately 76% of women with negative HPV and diagnosis of HSIL (CIN2 and CIN3) on initial biopsy had confirmed HSIL (CIN2 and CIN3) in subsequent LEEP follow-up. Diffuse p16 immunostaining pattern is the hallmark of HSIL because it correlates 100% with CIN2 and CIN3 lesions between initial biopsy and LEEP specimens, regardless of the HPV status. The negative predictive value for p16 immunoreactivity to predict cervical lesions less than high grade is almost 100% in our study. Our study suggests that when a woman is negative for HPV and also negative for p16, diagnosis of HSIL should be very cautious in void of unnecessary LEEP procedures.

p16INK4a immunohistochemistry in cervical biopsy specimens: A systematic review and meta-analysis of the interobserver agreement

OBJECTIVES

The interpretation of cervical biopsy specimens guides management of women with suspected cervical cancer precursors. However, morphologic evaluation is subjective and has low interobserver agreement. Addition of p16(INK4a) immunohistochemistry may improve interpretation.

METHODS

We performed a systematic review and meta-analysis of published data on interobserver agreement of p16(INK4a) positivity using p16(INK4a) immunohistochemistry and of cervical intraepithelial neoplasia grade 2 (CIN2+) and CIN grade 3 (CIN3+) classification using H&E morphology in conjunction with p16(INK4a) in comparison with H&E morphology alone.

RESULTS

The literature search revealed five eligible articles. The results show strong agreement of pathologists' interpretation of cervical biopsy specimens as p16(INK4a) positive or negative (pooled κ = 0.90; 95% confidence interval [CI], 0.88-0.92) and significantly higher agreement for a CIN2+ diagnosis with H&E morphology in conjunction with p16(INK4a) (κ = 0.73; 95% CI, 0.67-0.79) compared with H&E morphology alone (κ = 0.41; 95% CI, 0.17-0.65). Also, a slightly higher agreement for CIN3+ can be observed (κ = 0.66; 95% CI, 0.39-0.94 for H&E morphology in conjunction with p16(INK4a) and κ = 0.61; 95% CI, 0.44-0.78 for H&E morphology alone), but this difference was not statistically significant.

CONCLUSIONS

The published literature indicates improved interobserver agreement of the diagnosis of CIN2+ with the conjunctive use of H&E morphology with p16(INK4a) immunohistochemistry compared with H&E morphology alone.

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.

Reducing interrater variability and improving health care: a meta-analytical review

OBJECTIVES

In the scientific literature about reliability, the main approach to increasing reliability seems to involve increasing the number of observers and improving the instrument used. Other aspects for improving reliability - like the training of raters - seem to receive less notice. It is worth asking whether this technical approach could be complemented by training the user of the instrument. A systematic meta-analytical review of the research literature was performed to answer this question and examine the effectiveness of planned interventions for improving interrater reliability of health care professionals.

METHOD

The databases of PubMed (MEDLINE), Embase, Omega and PsycINFO were searched. The inclusion criteria were met by 57 studies. Details extracted from the studies included the study design, the number of observers and the number of observed cases, the intervention, the type of instrument (whether or not it was highly technical), and statistical information about the agreement before and after the intervention. Interventions were categorized into three groups: training of professionals, improving the diagnostic instrument and a combination of training and improving the instrument. A meta-analysis was performed by means of linear regression.

RESULTS

The interventions were arranged according to their effectiveness in improving the diagnostic instrument (mean change: β = 0.13), training combined with improving the instrument (mean change: β = 0.10) and training (mean change: β = 0.09).

CONCLUSION

On average, although all types of interventions are effective, improving the diagnostic instrument seems to be the most effective. Especially when highly technical instruments were concerned, improvement proved to be very effective (β = 0.52). Because instrumental variables constitute a major source of error, improving the instrument is an important approach. However, this review offers solid arguments that can complement the literature and practice, with a focus on training the user of the instrument.

Evaluation of cervical cone biopsies for coexpression of p16INK4a and Ki-67 in epithelial cells

Diffuse overexpression of p16(INK4a) in basal and parabasal cells of cervical epithelium is a hallmark of human papillomavirus-mediated transformation. Focal p16(INK4a) expression is occasionally observed in nondysplastic epithelium. In normal cells, expression of p16(INK4a) triggers cell cycle arrest. However, cells undergoing transformation in intraepithelial lesions actively proliferate. To prove that the different expression patterns of p16(INK4a) , i.e., focal versus diffuse, reflect biologically different entities, we hypothesized that p16(INK4a) -positive cells in epithelia displaying focal p16(INK4a) expression pattern do not coexpress proliferation-associated Ki-67 protein, while p16(INK4a) -positive cells in lesions with diffuse p16(INK4a) expression may do. A total of 138 cervical cone biopsies were stained for the expression of p16(INK4a) and Ki-67 using a primary antibody cocktail. All metaplastic lesions (n = 21) displayed focal staining for p16(INK4a) , and in all of these lesions p16(INK4a) -positive cells were found to be negative for Ki-67 expression. Diffuse expression of p16(INK4a) was observed in 12/21 (57.1%) cervical intraepithelial neoplasia (CIN) 1 lesions, all of them simultaneously showed Ki-67 immunoreactivity in a large proportion of p16(INK4a) -positive cells. Seventeen of 23 (73.9%) CIN2 lesions and all 27 (100%) CIN3/carcinoma in situ (CIS) as well as all 46 (100%) carcinoma cases displayed diffuse and combined expression of p16(INK4a) and Ki-67. Coexpression of Ki-67 and p16(INK4a) in the same cell is entirely restricted to cervical lesions displaying diffuse p16(INK4a) expression, whereas in lesions with focal p16(INK4a) expression, p16(INK4a) -expressing cells are negative for Ki-67. Thus, diffuse expression of p16(INK4a) reflects lesions with proliferation-competent cells, while p16(INK4a) -expressing cells associated with focal expression patterns are cell cycle arrested.

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.

Detection of cervical intraepithelial neoplasias and cancers in cervical tissue by in vivo light scattering

OBJECTIVE: To examine the utility of in vivo elastic light scattering measurements to identify cervical intraepithelial neoplasias (CIN) 2/3 and cancers in women undergoing colposcopy and to determine the effects of patient characteristics such as menstrual status on the elastic light scattering spectroscopic measurements. MATERIALS AND METHODS: A fiber optic probe was used to measure light transport in the cervical epithelium of patients undergoing colposcopy. Spectroscopic results from 151 patients were compared with histopathology of the measured and biopsied sites. A method of classifying the measured sites into two clinically relevant categories was developed and tested using five-fold cross-validation. RESULTS: Statistically significant effects by age at diagnosis, menopausal status, timing of the menstrual cycle, and oral contraceptive use were identified, and adjustments based upon these measurements were incorporated in the classification algorithm. A sensitivity of 77±5% and a specificity of 62±2% were obtained for separating CIN 2/3 and cancer from other pathologies and normal tissue. CONCLUSIONS: The effects of both menstrual status and age should be taken into account in the algorithm for classifying tissue sites based on elastic light scattering spectroscopy. When this is done, elastic light scattering spectroscopy shows good potential for real-time diagnosis of cervical tissue at colposcopy. Guiding biopsy location is one potential near-term clinical application area, while facilitating "see and treat" protocols is a longer term goal. Improvements in accuracy are essential.