Descriptive evidence that risk profiles for cervical intraepithelial neoplasia 1, 2, and 3 are unique

CIN III lesions and regression: retrospective analysis of 635 cases

Background

The rate of spontaneous regression in CIN III lesions is controversial. Whereas some studies have reported high regression rates of up to 38 % after prolonged biopsy-conus intervals, others have shown rates between 0 and 4 % without considering time intervals. Identification of young patients with potentially regressing CIN III could offer the chance to avoid conisation, thus lowering the risk of preterm labour.

Methods

To further clarify the facts, we retrospectively compared 635 biopsies showing CIN III with the diagnosis of the conisation. Either regression (CIN I or less) or non-regression (CIN II and higher) was recorded. Diagnoses were made by light microscopy and p16 immunostaining.

Results

Conisation was performed between 2 and 463 days after biopsy (median 8.9 weeks). Six hundred twenty one (98 %) were HPV-HR positive. In 345 cases, HPV subtyping was available, showing HPV16 infection in 57 %. Routine processing of the conisation tissue showed no corresponding CIN lesion (< CIN II) in 40 cases (6.3 %). Additional step sectioning of the tissue revealed small CIN II+ lesions in 80 %. Finally, eight cases (1.3 %) fulfilled the criteria of regression. No regression was seen in HPV16 positive cases. Twelve invasive carcinomas were detected by routine processing of the conisation tissue.

Conclusion

These results are in contrast with some prior reports that might have overestimated spontaneous regression of CIN III. Study size and an accurate discrimination between CIN II and CIN III lesions by histopathology seem to be the most likely factors to explain the diverging results published. Complete step sectioning of the whole tissue is also mandatory in questionable cases. Although theories exist that the initial biopsy might stimulate the immune system, thus triggering regression within weeks, our data do not substantially support such a mechanism. Overall, the chance of a CIN III lesion to regress rapidly within weeks or months after diagnosis seems to be small. We found more previously undetected invasive cancer than we observed regression. Therefore, a change in the current policy to treat CIN III lesions is unwarranted.

Three-year risk of cervical precancer and cancer after the detection of low-risk human papillomavirus genotypes targeted by a commercial test

OBJECTIVE

To investigate the risk of cervical precancer and cancer associated with detection of human papillomavirus (HPV) 6, 11, and 42.

METHODS

We used data from the New Mexico Human Papillomavirus Pap Registry. A stratified sample of 59,644 residual cervical cytology specimens from a population of 379,000 underwent HPV genotyping. We measured the 3-year cumulative incidence of cervical intraepithelial neoplasia grade 2 or more severe (CIN 2+) and grade 3 or more severe (CIN 3+) after detection of single HPV 6, 11, or 42 infections or single or multiple infections of HPV 6, 11, or 42 ("HPV 6, 11, 42, or combinations"; n=581).

RESULTS

The overall prevalence of a single infection of HPV 6, 11, or 42 was 0.8% (95% confidence interval [CI] 0.7-0.9%). The 3-year risks of CIN 2+ and CIN 3+ after HPV 6, 11, 42, or combinations infections (n=581) were 0.4% (CI 0.1-0.7%) for CIN 2+ and 0.0% for CIN 3+ (nota bene, no CI was calculable because no events occurred), respectively. By comparison, the 3-year risks of CIN 2+ and CIN 3+ after a negative HPV result (n=27,522) were 0.2% (95% CI 0.1-0.2%) and 0.1% (95% CI 0.0-0.1%), respectively.

CONCLUSION

Detection of HPV 6, 11, 42, or combinations in the absence of high-risk HPV types does not identify women at increased 3-year risk for cervical precancer. Testing for HPV 6, 11, 42, or combinations of those types should be discontinued because it has no proven benefit to patients.

LEVEL OF EVIDENCE

II.

Scoring system and management algorithm assessing the role of survivin expression in predicting progressivity of HPV infections in precancerous cervical lesions

BACKGROUND

To identify the risk factors and assess the role of survivin in predicting progessivity precancerous cervical lesions.

MATERIALS AND METHODS

This case-control study was conducted from October 2009 until May 2010. We obtained 74 samples, classified according to the degree of cervical intraepithelial neoplasia (CIN): 19 samples for CIN 1, 18 samples for CIN 2, 18 samples for CIN 3, and 19 samples as controls. Demographic profiles and risk factors assesment, histopathologic examination, HPV DNA tests, immunocytochemistry (ICC) and immunohistochemistry (IHC) staining for survivin expression were performed on all samples. Data was analyzed with bivariate and multivariate analysis.

RESULTS

Multivariate analysis revealed significant risk factors for developing precancerous cervical lesions are age <41 years, women with ≥2 sexual partners, course of education ≥13 years, use of oral contraceptives, positive high-risk HPV DNA, and high survivin expression by ICC or IHC staining. These factors were fit to a prediction model and we obtained a scoring system to predict the progressivity of CIN lesions.

CONCLUSIONS

Determination of survivin expression by immunocytochemistry staining, along with other significant risk factors, can be used in a scoring system to predict the progressivity of CIN lesions. Application of this scoring system may be beneficial in determining the action of therapy towards the patient.

The role of co-factors in the progression from human papillomavirus infection to cervical cancer

OBJECTIVE

Co-factors for cervical cancer, including oral contraceptive (OC) use, smoking and multiparity have been identified; however, the stage at which they act in cervical carcinogenesis is not clear. We compared established risk factors among women with CIN2 and CIN3 to evaluate the heterogeneity of these factors in precancer and also assessed their role during cervical carcinogenesis.

METHODS

The current analysis included 2783 women with various stages of cervical disease who were enrolled in the Study to Understand Cervical Cancer Early Endpoints and Determinants (SUCCEED) and the Biopsy Study. Associations of co-factors within cervical precancer and at different stages of cervical carcinogenesis were estimated using logistic regression.

RESULTS

Long-term OC use (10+years vs. never: OR=2.42, 95% CI: [1.13-5.15]), multiparity (3+ births vs. nulliparous: OR=1.54 [1.04-2.28]), smoking (ever vs. never: OR=1.95 [1.48-2.58]), and no Pap test in the previous five years (2.05 [1.32-3.17]) were positively associated with CIN3 compared to CIN2. We observed that long-term OC use, parity and smoking were associated with an increased risk of CIN3 compared to <CIN2 (1.97 [1.12-3.46]; 2.23 [1.59-3.11]; 2.60 [2.04-3.30], respectively), whereas associations were not significantly different (OC use, parity) or showed decreased risk (smoking) when comparing cancer to CIN3.

CONCLUSIONS

Differences in established risk factors suggest that CIN3 is a more specific definition of precancer than CIN2. Hormonally-related factors and smoking play a role in the transition from human papillomavirus infection to precancer.

Co-factors of high-risk human papillomavirus infections display unique profiles in incident CIN1, CIN2 and CIN3

In addition to oncogenic 'high-risk' human papillomaviruses (HR-HPV), several co-factors are needed in cervical carcinogenesis, but it is poorly understood whether these HPV co-factors associated with incident cervical intraepithelial neoplasia (CIN) grade 1 are different from those required for progression to CIN2 and CIN3. To gain further insights into the true biological differences between CIN1, CIN2 and CIN3, we assessed HPV co-factors increasing the risk of incident CIN1, CIN2 and CIN3. Data from the New Independent States of the Former Soviet Union (NIS) Cohort (n = 3187) and the Latin American Screening (LAMS) Study (n = 12,114) were combined, and co-factors associated with progression to CIN1, CIN2 and CIN3 were analysed using multinomial logistic regression models with all covariates recorded at baseline. HR-HPV-positive women (n = 1105) represented a subcohort of all 1865 women prospectively followed up in both studies. Altogether, 90 (4.8%), 39 (2.1%) and 14 (1.4%) cases progressed to CIN1, CIN2 and CIN3, respectively. Baseline HR-HPV was the single most powerful predictor of incident CIN1, CIN2 and CIN3. When controlled for residual HPV confounding by analysing HR-HPV-positive women only, the risk profiles of incident CIN1, CIN2 and CIN3 were unique. Completely different HPV co-factors were associated with progression to CIN1, CIN2 and CIN3 in univariate and multivariate analyses, irrespective of whether non-progression, CIN1 or CIN2 was used as the reference outcome. HPV co-factors associated with progression to CIN1, CIN2 and CIN3 display unique profiles, implicating genuine biological differences between the three CIN grades, which prompts us to re-visit the concept of combining CIN2 with CIN3 or CIN1.

Risk estimates for persistent high-risk human papillomavirus infections as surrogate endpoints of progressive cervical disease critically depend on reference category: analysis of the combined prospective cohort of the New Independent States of the Former Soviet Union and Latin American Screening Studies

Summary

To make feasible future clinical trials with new-generation human papillomavirus (HPV) vaccines, novel virological surrogate endpoints of progressive disease have been proposed, including high-risk HPV (HR-HPV) persistence for six months (6M+) or 12 months (12M+). The risk estimates (relative risks [RRs]) of these ‘virological endpoints’ are influenced by several variables, not yet validated adequately. We compared the impact of three referent groups: (i) HPV-negative, (ii) HPV-transient, (iii) HPV-mixed outcome on the risk estimates for 6M+ or 12M+ HR-HPV persistence as predictors of progressive disease. Generalized estimating equation models were used to estimate the strength of 6M+ and 12M+ HR-HPV persistence with disease progression to squamous intraepithelial lesions (SILs), cervical intraepithelial neoplasia (CIN) grade 1 +, CIN2+, CIN/SIL endpoints, comparing three optional reference categories (i)-(iii) in a prospective sub-cohort of 1865 women from the combined New Independent States of the Former Soviet Union (NIS) and Latin American Screening (LAMS) studies cohort ( n = 15,301). The RRs of these viral endpoints as predictors of progressive disease are affected by the length of viral persistence (6M+ or 12M+) and the surrogate endpoint (SIL, CIN1, CIN2, CIN/SIL). Most dramatic is the effect of the referent group used in risk estimates, with the HPV-negative referent group giving the highest and most consistent RRs for both 6M+ and 12M+ viral persistence, irrespective of which surrogate is used. In addition to deciding on whether to use 6M+ or 12M+ persistence criteria, and cytological, histological or combined surrogate endpoints, one should adopt the HPV-negative referent group as the gold standard in all future studies using viral persistence as the surrogate endpoint of progressive disease.

HLA-Cw group 1 ligands for KIR increase susceptibility to invasive cervical cancer

Inherited genetic polymorphisms within immune response genes have been shown to associate with risk of invasive cervical cancer (ICC) and its immediate precursor, cervical intraepithelial neoplasia grade 3. Here, we used the transmission/disequilibrium test to detect disease-liability alleles and investigate haplotype transmission of KIR and HLA class I polymorphisms in a large family-based population of women with cervical cancer and their biological parents (359 trios). The effect of distinct human papillomavirus types was also explored. HLA-Cw group 1 (HLA-Cw alleles with asparagine at position 80), which serves as ligand for certain killer immunoglobulin-like receptors (KIR), was significantly overtransmitted in women with ICC (P = 0.04), and particularly in the subgroup of women infected with high risk HPV16 or 18 subtypes (P = 0.008). These data support the involvement of the HLA-C locus in modulating the risk of cervical neoplasia perhaps through its function as ligands for KIR, but functional studies are essential to confirm this hypothesis.

Human papillomavirus vaccines: current status and future prospects

Worldwide, cervical cancer is the second most common cancer of women. Less-developed countries bear the greatest burden in terms of morbidity and mortality, largely due to the lack of organized screening programmes. Cervical cancer is the first cancer shown to be caused solely by virological agents: oncogenic genotypes of human papillomavirus (HPV). Two recently developed prophylactic cervical cancer vaccines, which are based on viral-like particle (VLP) technology of HPV, have the capacity to diminish a large proportion of cervical cancer cases worldwide. However, to be successful public health tools, they need to be widely implemented to the appropriate target population, preferably prior to first sexual intercourse. To increase vaccination coverage, national programmes in some countries have also included catch-up vaccination, for a limited time period, to young adult women aged up to 26 years. Despite the excellent efficacy for high-grade dysplasia due to vaccine-related HPV types (near to 100%) and immunogenicity induced against the HPV types 16 and 18 in females naive to those HPV types pre-vaccination, some form of cervical precancer screening will still be necessary. Immunity to HPV is primarily type specific, and thus protection induced by the current generation of vaccines, based on a limited number of HPV VLP types, cannot provide complete protection against all oncogenic HPV types. Both these vaccines translate to protection of cervical cancer in the order of 70-75%, which represents the percentage of invasive cancers attributable to HPV-16 and -18. Challenges to ensuring the successful control of this largely preventable disease include endorsement by governments and policy makers, affordable prices, education at all levels, overcoming barriers to vaccination and continued adherence to screening programmes.