Human papillomaviruses and cervical neoplasia: a model for carcinogenesis

The significance of marked nuclear atypia in grade 1 cervical intraepithelial neoplasia

Approximately 10% to 15% of cases of grade 1 cervical intraepithelial neoplasia are found to have progressed to a high-grade squamous intraepithelial lesion or higher at follow-up, and there are presently no reliable morphological predictors of this subset. It has recently been reported that cases of grade 1 cervical intraepithelial neoplasia that display marked nuclear atypia (defined as cases with at least 5 epithelial cells with nuclear enlargement of at least 5 times the size of an intermediate cell, and/or multinucleation of at least 5 nuclei.) have a substantially higher rate of high-grade squamous intraepithelial lesion on short-term follow-up and may, therefore, require more aggressive initial management. We report herein our experience with a cohort of such cases. After a review of consecutive cervical biopsies, 352 cases with grade 1 cervical intraepithelial neoplasia were classified into group 1 (grade 1 cervical intraepithelial neoplasia with marked atypia, n = 31) and group 2 (grade 1 cervical intraepithelial neoplasia without marked atypia, n = 321). The average follow-up rates for groups 1 and 2 were 93.55% (29/31) and 90.65% (291/321), respectively. Average follow-up durations were 14.3 and 17.9 months, respectively. The follow-up high-grade squamous intraepithelial lesion rate of the cases with marked atypia was 10.34%, as compared with 11.68% for cases without marked atypia. The follow-up interpretive frequency (in cytologic samples) of "low-grade squamous intraepithelial lesion" was significantly higher in group 1(19/29 versus 114/291, P = .009). However, no significant differences were identified between groups 1 and 2 regarding the interpretive frequencies of either high-grade squamous intraepithelial lesion (3/29 versus 34/291, P = 1) or "negative for intraepithelial lesion or malignancy" (6/29 versus 56/291, P = .8) in follow-up cytologic samples. In subsets of both groups in which high-risk human papillomavirus testing was performed in the Papanicolaou test sample that immediately preceded the index cervical biopsies, no significant differences in viral load were found. In conclusion, grade 1 cervical intraepithelial neoplasia with marked atypia does not have a higher follow-up high-grade squamous intraepithelial lesion rate than grade 1 cervical intraepithelial neoplasia without marked atypia in our patient population. Further studies are required to address the significance of marked atypia in grade 1 cervical intraepithelial neoplasia and whether patients with this finding should be managed differently.

Human papillomavirus type 16 mutant E7 protein induces oncogenic transformation via up-regulation of cyclin A and cdc25A

A new mutant human papillomavirus type 16 E7 gene, termed HPV16 HBE7, was isolated from cervical carcinoma biopsy samples from patients in an area with high incidence of cervical cancer (Hubei province, China). A previous study showed that the HPV16 HBE7 protein was primarily cytoplasmic while wild-type HPV16 E7 protein, termed HPV16 WE7, was concentrated in the nucleus. With the aim of studying the biological functions of HPV16 HBE7, the transforming potential of HPV16 HBE7 in NIH/3T3 cells was detected through observation of cell morphology, cell prolieration assay and anchorage-independent growth assay. The effect of HPV16 HBE7 on cell cycle was examined by flow cytometry. Dual-luciferase reporter assay and RT-PCR were used to investigate the influence of HPV16 HBE7 protein on the expression of regulation factors associated with G1/S checkpoint. The results showed that HPV16 HBE7 protein, as well as HPV16 WE7 protein, held transformation activity. NIH/3T3 cells expressing HPV16 HBE7 could easily transition from G1 phase into S phase and expressed high level of cyclin A and cdc25A. These results indicated HPV16 mutant E7 protein, located in the cytoplasm, induces oncogenic transformation of NIH/3T3 cells via up-regulation of cyclin A and cdc25A

The biomarkers of human papillomavirus infection in tonsillar squamous cell carcinoma-molecular basis and predicting favorable outcome

Presence of human papillomavirus (HPV) in variable proportions in tonsillar squamous cell carcinoma tissues has been demonstrated by several worldwide studies. Some reports emphasized the significance of HPV in predicting a better prognosis, as well as ethnic differences between Chinese and Caucasians. In order to understand the biological role of HPV and find out clinically accessible methods to determine its prognostic significance in primary tonsillar squamous cell carcinoma, we collected 92 patients with primary tonsillar squamous cell carcinoma diagnosed or treated in National Taiwan University Hospital, for whom archival tumor tissue were available. Immunohistochemical stains of p16(INK4A), high-risk HPV in situ hybridization, and nested polymerase chain reaction (PCR)-based genechips were performed to detect HPV infection and determine its genotype. Clinical data were compared with HPV infection detected by the different methods mentioned above. Real-time PCR was also performed on the HPV16-positive [HPV16(+)] lesions to understand viral integration status. The positive rates of nested PCR-based genechips, overexpression of p16(INK4A), and high-risk HPV in situ hybridization were 75% (69/92), 53% (49/92), and 44% (40/92), respectively. Both overexpression of P16(INK4A) and high-risk HPV in situ hybridization positivity were associated with favorable prognoses (P=0.004 and 0.001, respectively) and also independent prognostic factors in multivariate analyses (P=0.01 and 0.01, respectively). The positivity of nested PCR-based genechips was not statistically significant. From our data, primary tonsillar squamous cell carcinoma with positive immunohistochemical stains of p16(INK4A) and/or high-risk HPV in situ hybridization is associated with a better outcome, and both methods may serve as clinically accessible markers.

Human papillomavirus: molecular and cytologic/histologic aspects related to cervical intraepithelial neoplasia and carcinoma

Cervical cancer is unique among human cancers because it was the first cancer discovered to be virtually solely attributable to the effects of an infectious agent. Numerous epidemiologic and laboratory studies have confirmed a strong causal association between human papillomavirus infection and the development of premalignant and malignant lesions of the uterine cervix, and human papillomavirus-mediated malignant transformation is an ideal model system for the study of virally mediated carcinogenesis. Neoplastic transformation of affected cervical epithelium appears to be a direct consequence of the unregulated overexpression of viral oncoproteins that have central roles in the normal viral replicative cycle. This review is focused on the mechanisms that regulate the normal papillomavirus life cycle and on the mechanisms that appear to have central roles in malignant transformation of the cervical mucosa.

Expression of p21Cip1/Waf1 and p27Kip1 in Small Cell Neuroendocrine Carcinoma of the Uterine Cervix

Small-cell neuroendocrine carcinoma of the uterine cervix (SCCC), a rare but malignant cervical neoplasm, has a highly aggressive phenotype that requires more intensive treatment than other cervical tumors. Immunohistochemical methods were used to compare the expression of p21Cip1/Waf1 and p27Kip1 in SCCC and squamous cell carcinoma, the most common type of cervical cancer. In SCCC, p21 expression was significantly reduced compared with squamous cell carcinoma, whereas expression of p27 was similar in both carcinomas. Reduced expression of p21 could be a helpful diagnostic marker and may contribute to the invasive phenotype of SCCC.

Reducing the burden of glandular carcinomas of the uterine cervix

Widespread use of the Papanicolaou test for the screening of cervical cancers has lead to a significant decline in overall incidence and mortality rates over the past 3 decades. When different histologic types of cervical cancers are considered and trends are reexamined, it becomes apparent that observed declines are reflective of squamous cell carcinomas predominantly; the rates for adenocarcinomas continue to rise. This rise in incidence may be due to the greater difficulty in screening for glandular precursor lesions that often arise high within the endocervical canal. Reducing the incidence and mortality rates that are associated with adenocarcinomas can be accomplished by using improved screening techniques and large-scale implementation of cervical cancer vaccines that target the predominant oncogenic human papillomavirus types that are associated with adenocarcinoma.

Variations of mitotic index in normal and dysplastic squamous epithelium of the uterine cervix as a function of endometrial maturation

Cervical intraepithelial neoplasia is a premalignant (dysplastic) lesion that is characterized by abnormal cellular proliferation, maturation and nuclear atypia. The intraepithelial distribution, density, and nature (typical or atypical) of mitotic figures are routinely utilized diagnostic criteria to grade dysplasia and to distinguish high-grade dysplasia from potential histologic mimics such as transitional metaplasia, atrophy or immature squamous metaplasia. In this study, we evaluated the total mitotic indices of the cervical epithelia in hysterectomy specimens from patients with and without dysplastic lesions and investigated a possible relationship between mitotic index and hormonal status, using the endometrial maturation phase as a surrogate indicator of the latter. Two hundred seventy-four cervices from hysterectomy specimens (135 cases without dysplasia, 33, 35 and 71 cases with grades 1, 2 and 3 cervical intraepithelial neoplasia, respectively) were analyzed. A cervical mitotic index (total mitotic figures/10 high-power fields in the most proliferative area) was determined for each case. The endometrium in each case was classified into atrophic, early proliferative, late proliferative and secretory. For all three dysplasia grades, cases in the proliferative endometrium group always had a higher average mitotic index than those in the secretory and atrophic endometrium groups; this observation also held true for the benign cases. Furthermore, in all three dysplasia grades, the average mitotic index was always lowest in the atrophic endometrium group. Although the mitotic index showed expected patterns of increases with increasing dysplasia grades for most of the endometrial phases, this was not a universal finding. Notably, the average mitotic index for our cervical intraepithelial neoplasia 1 cases with late proliferative endometrium was higher than our cervical intraepithelial neoplasia 2 cases with secretory and atrophic endometrium. It is concluded that hormonal status, as reflected in endometrial maturation, can significantly affect the mitotic index of dysplastic squamous epithelium of the uterine cervix. Our findings confirm that the pathologic grading of dysplasia, especially in equivocal cases such as in metaplastic squamous epithelium, should not be solely dependent on the finding mitoses in the cervical squamous epithelium. The full composite of histopathologic features should form the basis for this determination.

Efficiency of immunohistochemical p16 expression and HPV typing in cervical squamous intraepithelial lesion grading and review of the p16 literature

Diagnosing and grading cervical cancer precursors is challenging. This study investigates the presence of HPV infection, the expression of p16, and any correlation between these two findings. H&E-stained slides of cervical loop excision materials diagnosed as LSIL and HSIL were reviewed. An immunohistochemical panel consisting of p16 as well as of all HPV types and HR-HPV types was applied. Staining of p16 was evaluated according to distribution extent and degree of intensity. All HSIL cases and 80% of LSIL cases were positive for p16. In HSIL cases, the staining distribution was as follows: 50% full thickness, 45% basal, and 5% rare. The staining intensity for the same cases was strong in 70%, variable in 20%, and weak in 10% accordingly. In LSIL cases, staining distribution was basal in 58.3% and rare in 41.7%. None of the LSIL cases showed full thickness of p16 positivity. The staining intensity of the same cases was strong in 25%, variable in 16.7%, and weak in 58.3%. Of all cases, 48.6% were positive for screening kit (all HPV types), and 31.4% of all cases were positive for HR-HPV. The distribution of this positivity was 35% for HSIL and 26.6% for LSIL cases. The total HPV-type positivity rate was 48.6%, the distribution being 50% for HSIL and 46.6% for LSIL cases. p16 is a highly sensitive marker for cervical epithelial dysplasia. Strong and full thickness staining of p16 in the cervix epithelium is highly supportive of HSIL, while weak and basal/rare staining favors LSIL. All HPV-positive cases were also p16-positive, but no statistically significant relationship between HPV infection positivity and the intensity and distribution of p16 was found. HPV is not helpful in the grading of SIL, as an unignorable rate of HR-HPV positivity (26.6%) was detected in LSIL group.

Development of combined DNA-based piezoelectric biosensors for the simultaneous detection and genotyping of high risk Human Papilloma Virus strains

BACKGROUND

Human Papilloma Virus (HPV) is a DNA virus belonging to the Papovavirus family. Genital HPV types have been subdivided into medium-low risk, and high-risk (HPV 16 and 18), frequently associated with cervical cancer. Three DNA-based piezoelectric biosensors were here developed for a quick detection and genotyping of HPV.

METHODS

We developed a method for the detection and genotyping of HPV in human cervical scraping samples based on coupling DNA piezoelectric sensors with Polymerase Chain Reaction (PCR). The novelty of this work was the design and immobilisation of a degenerate probe (chosen in a conserved region of the viral genome) for the simultaneous detection of 16 virus strains and of two specific probes (chosen in a less-conserved region of the viral genome) for genotyping.

RESULTS

The three biosensors were optimised with synthetic oligonucleotides with good reproducibility (HPVdeg CV% (av) 9%, HPV16 CV%(av) 9%; HPV18 CV%(av) 11%) with a detection limit of 50 nM. Cervical scraping samples after PCR amplification (in 40-200 nM range), were tested without the need of label with high selectivity and reproducibility. The results were in agreement with a reference method used in routinary analysis.

CONCLUSION

Piezoelectric biosensors have proven to be suitable for detection and genotyping of HPV.

HPV status in sentinel nodes might be a prognostic factor in cervical cancer

OBJECTIVE

Although there have been studies that focused on the correlation between the HPV presence of pelvic lymph nodes and pathological metastasis in patients with cervical cancer, the biologic role of HPV DNA in lymph nodes still remains uncertain. We performed this study to investigate the correlation between the sentinel-node HPV status and pelvic lymph node metastasis in patients with cervical cancer. The patients were followed up for 3 years to evaluate the clinical role of HPV in sentinel nodes as a prognostic factor.

METHODS

From August 2001 to July 2003, 57 patients affected by stages IB-IIA cervical cancer had sentinel-node biopsies performed during radical hysterectomy and pelvic and paraaortic lymphadenectomy. Each detected sentinel node was divided into two parts. One part of them was submitted for frozen section examination and the other was submitted for HPV typing by oligonucleotide microarray. After follow-up, we analyzed the outcome of the patients with respect to the influence of sentinel-node HPV.

RESULTS

Sentinel nodes were identified in all patients. A total of 79 nodes from 57 patients were detected as sentinel nodes. Metastasis in the sentinel nodes were found in 10 patients (17.6%) by frozen section and 11 patients by pathologic examination. The results of sentinel lymph node frozen biopsy were statistically significant for predicting the metastasis of the pelvic lymph nodes (P<0.05), but showed one false-negative case. HPV DNA was detected in the cervical cancer lesions of 55 patients (96.5%) and 80.0% (44/55) of them were found to have HPV DNA in the sentinel nodes as well. HPV DNA was detected in sentinel nodes of 10 patients among 11 patients with lymph node metastasis. Disease recurred in five patients and one of them did not show pelvic lymph node metastasis at surgery. But, all of these patients had HPV in sentinel nodes. The combination of sentinel-node frozen biopsy and HPV typing showed a negative predictive value of 100% in predicting non-metastasis of lymph node and no recurrence of disease.

CONCLUSION

Our results suggested the possibility that sentinel-node HPV typing could play a supportive role to reduce the false-negative rate of the sentinel-node biopsy. All of five patients with recurrence had HPV infection in the sentinel nodes. Absence of HPV in sentinel nodes showed reliable negative predictive value for lymph node metastasis and recurrence. Additional study will be needed to confirm the clinical application of the sentinel-node procedure and to determine whether there is a correlation of HPV status of sentinel nodes to lymph node metastasis and recurrence in cervical cancer patients.

IR microspectroscopy: potential applications in cervical cancer screening

Screening exfoliative cytology for early dysplastic cells reduces incidence and mortality from squamous carcinoma of the cervix. In the developed world, screening programmes have adopted a 3-5 years recall system. In its absence, cervical cancer would be the second most common female cancer in these regions; instead, it is currently eleventh. However, there exist a number of limitations to the smear test even given the removal of contaminants using liquid-based cytology. It is prohibitively expensive, labour-intensive and subject to inaccuracies that give rise to significant numbers of false negatives. There remains a need for novel approaches to allow efficient and objective interrogation of exfoliative cytology. Methods that variously exploit infrared (IR) microspectroscopy are one possibility. Using IR microspectroscopy, an integrated 'biochemical-cell fingerprint' of the lipid, protein and carbohydrate composition of a biomolecular entity may be derived in the form of a spectrum via vibrational transitions of individual chemical bonds. Powerful statistical approaches (e.g. principal component analysis) now facilitate the interrogation of large amounts of spectroscopic data to allow the extraction of what may be small but extremely significant biomarker differences between disease-free and pre-malignant or malignant samples. An increasing wealth of literature points to the ability of IR microspectroscopy to allow the segregation of cells based on their disease status. We review the current evidence supporting its diagnostic potential in cancer biology.

Clinicopathologic features of early adenocarcinoma of the cervix initially managed with cervical conization

OBJECTIVE

To evaluate the clinicopathologic features of microinvasive adenocarcinoma of the cervix in order to guide the management of patients with this disease.

MATERIALS AND METHODS

A retrospective review was conducted of patients diagnosed with early invasive, <or=5 mm stromal invasion, adenocarcinoma of the cervix by a cervical conization between 1992 and 1999 at our institution. Information was abstracted on tumor histopathologic type, grade, and depth of invasion as well as presence or absence of disease at the margins of conization, lymphovascular spread, and the presence of disease in subsequent pathology specimens including the parametrium and pelvic lymph nodes (PLNs).

RESULTS

Thirty-three patients were identified. The mean age of the patients in the study population was 41.6 years (range, 29-53 years). Fifteen women were age 35 years or younger. Six patients had invasion<or=1 mm, 9 patients had invasion>1 mm and <or=2 mm, 6 patients had invasion>2 mm and <or=3 mm, 6 patients had invasion>3 mm and <or=4 mm, and 6 patients had invasion>4 mm and <or=5 mm. Three patients were treated with a conization only, 4 patients were treated with a simple hysterectomy, 25 patients were treated with a radical hysterectomy (RH) and PLN dissection (PLND), and 1 patient was treated with a radical trachelectomy and PLND. Ten patients had positive conization margins for invasive cancer, 3 patients had margins positive for adenocarcinoma in situ, 14 patients had negative margins, and in 6 patients the margin status could not be evaluated. Of the 10 patients with positive margins, 5 of 10 (50%) had residual disease in the subsequent surgical specimen. Three patients who underwent definitive management with conization alone originally had positive margins, underwent a second repeat conization, and are included in this group. Of the 16 patients with negative margins, no patient had residual disease in a subsequent surgical specimen. Of the 25 patients who underwent a RH and PLND, none had parametrial involvement and none had PLN involvement. All patients remained without evidence of disease at median follow-up of 30 months.

CONCLUSIONS

Historically, the standard management of early invasive adenocarcinoma of the cervix has been controversial, and some clinicians continue to favor radical treatments. Based on the absence of parametrial spread and PLN involvement in early lesions, physicians and patients should consider treatment with conization with negative margins (when future fertility is desired) or simple hysterectomy. Prospective studies are required to document the safety of this approach.

Involvement of tumor suppressor in lung cancer 1 gene expression in cervical carcinogenesis

Tumor suppressor in lung cancer 1 (TSLC1) is a tumor suppressor gene in non-small cell lung cancer, and loss of TSLC1 gene expression has been observed in a number of epithelial carcinomas and cancer-derived cell lines. We analyzed TSLC1 gene expression by real-time reverse transcription-polymerase chain reaction in 39 invasive cervical carcinomas, 34 cervical intraepithelial neoplasia (CIN) IIIs, 35 CIN IIs, 32 CIN I, 36 inflammation cervical tissues, and 30 normal cervix samples. Loss of TSLC1 gene expression was observed in 30 of 39 (77%) cervical carcinomas, 25 of 34 (73%) CIN IIIs, 9 of 35 (26%) CIN IIs, and 7 of 32 (22%) CIN Is but was not found in inflammation and normal cervix samples. Compared to normal cervical tissue, loss of TSLC1 gene was significantly high in CIN IIIs and cervical cancer (P = 0.00). Moreover, loss of TSLC1 gene expression is observed at a significantly higher frequency in CIN IIIs and cervical cancers than in CIN IIs (P < 0.05). The results show that loss of TSLC1 gene expression is an early event in cervical carcinogenesis and often accompanies invasive cervical cancers.

Neutralization of HPV16, 18, 31, and 58 pseudovirions with antisera induced by immunizing rabbits with synthetic peptides representing segments of the HPV16 minor capsid protein L2 surface region

Neutralizing antibody against human papillomavirus (HPV) minor capsid protein L2 can cross-neutralize different HPV genotypes in vitro. To identify the segments containing the cross-neutralization epitopes of HPV16 L2, we characterized antisera obtained by immunizing two rabbits with each of the ten synthetic peptides of 14 to 20 amino acids (aa) long, which represents a part of the HPV16 L2 sequence from aa 14 to 144. The antisera against the peptides within the region from aa 18 to 144 efficiently bound to HPV16 L1/L2-capsids and neutralized HPV16 pseudovirions, indicating that the region is displayed on the surface of the capsids and contains several neutralization epitopes. Antiserum against the peptide from aa 18 to 38 (anti-P18/38) cross-neutralized HPV18. Anti-P56/75 cross-neutralized HPV18, 31, and 58. Anti-P61/75 and anti-P64/81 cross-neutralized HPV18 and 58. Anti-P96/115 and the antiserum induced by a mutant P96/115 (S and T at aa 101 and 112 were replaced with L and S, respectively) cross-neutralized HPV31 and 58. The mixture of equal volumes of three antisera, anti-P18/38, anti-P56/75, and anti-mutant P96/115, neutralized HPV16, 18, 31, and 58 more efficiently than anti-P56/75 alone, suggesting that there is a synergistic effect of antibodies on the cross-neutralization. The cross-neutralization appears to be correlated with conserved aa sequences among HPV types. The data in this study provide a basis for designing vaccine antigens effective against a broader spectrum of the high-risk HPVs.

Human papillomavirus type 16 integration in cervical carcinoma in situ and in invasive cervical cancer

Integration of human papillomavirus type 16 (HPV-16) into the host DNA has been proposed as a potential marker of cervical neoplastic progression. In this study, a quantitative real-time PCR (qRT-PCR) was used to examine the physical status of HPV-16 in 126 cervical carcinoma in situ and 92 invasive cervical cancers. Based on criteria applied to results from this qRT-PCR assay, HPV-16 was characterized in carcinoma in situ cases as episomal (61.9%), mixed (i.e., episomal and integrated; 29.4%), and integrated (8.7%) forms. In invasive cervical cancer samples, HPV-16 was similarly characterized as episomal (39.1%), mixed (45.7%), and integrated (15.2%) forms. The difference in the frequency of integrated or episomal status estimated for carcinoma in situ and invasive cervical cancer cases was statistically significant (P = 0.003). Extensive mapping analysis of HPV-16 E1 and E2 genes in 37 selected tumors demonstrated deletions in both E1 and E2 genes with the maximum number of losses (78.4%) observed within the HPV-16 E2 hinge region. Specifically, deletions within the E2 hinge region were detected most often between nucleotides (nt) 3243 and 3539. The capacity to detect low-frequency HPV-16 integration events was highly limited due to the common presence and abundance of HPV episomal forms. HPV-16 E2 expressed from intact episomes may act in trans to regulate integrated genome expression of E6 and E7.

Statistical methods for panel data from a semi-Markov process, with application to HPV

Continuous-time, multistate processes can be used to represent a variety of biological processes in the public health sciences; yet the analysis of such processes is complex when they are observed only at a limited number of time points. Inference methods for such panel data have been developed for time homogeneous Markov models, but there has been little research done for other classes of processes. We develop likelihood-based methods for panel data from a semi-Markov process, where transition intensities depend on the duration of time in the current state. The proposed methods account for possible misclassification of states. To illustrate the methods, we investigate a three- and a four-state models in detail and apply the results to model the natural history of oncogenic genital human papillomavirus infections in women.

Epidemiology of HPV 16 and cervical cancer in Finland and the potential impact of vaccination: mathematical modelling analyses

BACKGROUND

Candidate human papillomavirus (HPV) vaccines have demonstrated almost 90%-100% efficacy in preventing persistent, type-specific HPV infection over 18 mo in clinical trials. If these vaccines go on to demonstrate prevention of precancerous lesions in phase III clinical trials, they will be licensed for public use in the near future. How these vaccines will be used in countries with national cervical cancer screening programmes is an important question.

METHODS AND FINDINGS

We developed a transmission model of HPV 16 infection and progression to cervical cancer and calibrated it to Finnish HPV 16 seroprevalence over time. The model was used to estimate the transmission probability of the virus, to look at the effect of changes in patterns of sexual behaviour and smoking on age-specific trends in cancer incidence, and to explore the impact of HPV 16 vaccination. We estimated a high per-partnership transmission probability of HPV 16, of 0.6. The modelling analyses showed that changes in sexual behaviour and smoking accounted, in part, for the increase seen in cervical cancer incidence in 35- to 39-y-old women from 1990 to 1999. At both low (10% in opportunistic immunisation) and high (90% in a national immunisation programme) coverage of the adolescent population, vaccinating women and men had little benefit over vaccinating women alone. We estimate that vaccinating 90% of young women before sexual debut has the potential to decrease HPV type-specific (e.g., type 16) cervical cancer incidence by 91%. If older women are more likely to have persistent infections and progress to cancer, then vaccination with a duration of protection of less than 15 y could result in an older susceptible cohort and no decrease in cancer incidence. While vaccination has the potential to significantly reduce type-specific cancer incidence, its combination with screening further improves cancer prevention.

CONCLUSIONS

HPV vaccination has the potential to significantly decrease HPV type-specific cervical cancer incidence. High vaccine coverage of women alone, sustained over many decades, with a long duration of vaccine-conferred protection, would have the greatest impact on type-specific cancer incidence. This level of coverage could be achieved through national coordinated programmes, with surveillance to detect cancers caused by nonvaccine oncogenic HPV types.

Increased Ki-67 proliferative index and absence of P16INK4 in CIN-HPV related pathogenic pathways different from cervical squamous intraepithelial lesion

BACKGROUND/AIM

It is generally assumed that similar pathways are involved in human papillomavirus (HPV) induced pathogenesis of cervical squamous intraepithelial lesions (SILs) and cancers and a subset of conjunctival intraepithelial neoplasm (CIN)-that the malignancies or pre-cancerous lesions arise through HPV oncoproteins E6 and E7, which disrupt the pathways of p53 and the product of the retinoblastoma (Rb) gene and, in turn, increase the protein product of gene p16INK4 through the mechanism of positive feedback. Several cell cycle molecules are detected to test this hypothesis.

METHODS

Nine cases of CIN and eight non-CIN cases were analysed for the expression of Ki-67, pRb, p53, and p16INK4 via immunohistochemistry. Nine cases of cervical high grade squamous intraepithelial lesion (HSIL), and 10 cases of cervical low grade squamous intraepithelial lesion (LSIL) were included for stain control of p16INK4a, and comparison of p16INK4a expression to CIN cases. A nested polymerase chain reaction and a genechip HPV typing were used to detect HPV infection and types in the CIN and non-CIN samples

RESULTS

HPV positivity was demonstrated in all of the CIN lesions but in none of the non-CIN lesions. The Ki-67 proliferative index (Ki-67 PI) was statistically higher in the CIN group than the non-CIN group; however, there were no differences of expression of pRb and p53 between the two groups and no expression of p16INK4 in all cases. All nine cases of HSIL, and seven out of 10 cases of LSIL used for stain control were immunoreactive for p16INK4a. There were statistically significant differences in overexpression of p16INK4a between the CINs and SILs

CONCLUSIONS

The Ki-67 proliferative index may be a sensitive marker for CIN lesions and these results, with significant differences in overexpression of p16INK4a between CINs and SILs, may provide new evidence that HPV related mucosal dysplasia in different anatomical locations may lead to dissimilar molecular pathways.

Infection of human papillomavirus and overexpression of dihydrodiol dehydrogenase in uterine cervical cancer

OBJECTIVE

To determine the association of human papillomavirus (HPV) infection with the expression of dihydrodiol dehydrogenase (DDH) in uterine cervical cancer (UCC).

METHODS

In situ hybridization (ISH) and immunohistochemistry were applied to examine pathological specimens of 145 patients with UCC.

RESULTS

By ISH, HPV16/18 DNA was detected in 108 (74.5%) UCC cases. DDH expression determined by immunohistochemistry was detected in 81 (75%) lesions among 108 HPV-positive cases. In contrast, of 37 HPV-negative cases, DDH was only detected in 16 (43.2%) of the lesions. A significant correlation was found between DDH expression and the presence of HPV (P < 0.001), FIGO stage (P = 0.004), lymph node involvement (P < 0.001), as well as patients' survival (P = 0.002). In vitro, DDH expression was also found closely associated with HPV infection, and DDH content was proportional to cell sensitivity for cisplatin and doxorubicin.

CONCLUSIONS

HPV infection provokes local inflammation, which can then induce DDH expression and drug resistance in UCC. The detailed biological relationship among HPV infection, expression of DDH and drug resistance, however, remains to be clarified.

p14ARF and p16INK4A, two products of the same gene, are differently expressed in cervical intraepithelial neoplasia

OBJECTIVE

To study the expression patterns of two different tumor suppressor proteins p16INK4A and p14ARF in cervical lesions. Both proteins are encoded by the same INK4A/ARF gene on chromosome 9p21. The expression patterns of these two proteins, both playing a central role in the cell cycle, were analyzed in detail in CIN, carcinomas, and normal epithelium to test the hypothesis that p16INK4A positive cells also demonstrate p14ARF expression.

METHODS

Serial tissue sections of 9 CIN1 lesions, 10 CIN2 lesions, 12 CIN3 lesions, and 7 carcinomas were stained with monoclonal antibodies against p16INK4A and p14ARF. The short fragment polymerase chain reaction hybridization line probe assay was used to detect HPV.

RESULTS

Normal epithelium was negative for both proteins. Marked immunoreactivity (++) for p16INK4A and p14ARF was observed in 5/7 carcinomas, 10/12 CIN3, and 1/10 CIN2 lesions and 0/9 CIN1 lesions. Simultaneous expression (+ or ++) was found in 19/22 CIN2/3 and not in CIN1 lesions. The fraction of p16INK4A-stained cells increased with CIN-grade. Overexpression of p14ARF was observed in a subpopulation of p16INK4A positive cells, and exclusively found in lesions infected with high-risk HPV. In two CIN3 lesions with early stromal invasion, p14ARF positivity was mainly found in the invasive cells. In carcinomas, all cells showed p16INK4A expression, whereas p14ARF was limited to the peripheral cells of the invasive tumor nests and individual migrating tumor cells.

CONCLUSIONS

Overexpression of p14ARF is limited to a fraction of the p16INK4A-expressing cells and therefore it is likely that p14ARF- and p16INK4A expression are not induced by the same mechanisms. Before expression of p14ARF can be linked to invasion or invasive phenotype, larger series of (micro-) invasive squamous lesions need to be studied.

[Contribution of viral typing in cytological anomalies of the cervix]

Management practices for low-grade cervical lesions identified on screening swabs have been modified by research on the HPV. The appropriate approach for low-grade lesions is particularly difficult to determine due to the potential risk of malignant transformation coupled with the cost implications of treating lesions which will heal spontaneously in the majority of patients. The diagnosis of these low-grade lesions can be improved by thin layer swabs which have a greater sensitivity than conventional swabs. The current consensus is that swab results should be expressed according to the Bethesda classification. Routine tests for HPV (Hybrid Capture II) should be reserved for patients with an ASC-US swab. Colposcopy is indicated if the swab is positive for a low-grade lesion followed by cytology if the colposcopy is normal. If there is no evidence of HPV, search for oncogenes can lighten the treatment regimen due to the high specificity of the test. If a low-grade histological lesion (CIN1) is proven, cytocolposcopic surveillance should be proposed, surgical resection being undertaken in colposcopy cannot be performed. Here again search for HPV oncogenes at one year is an interesting alternative if the examination is negative. These practices are applicable in adolescents and HIV- positive patients who are particularly exposed to HPV.

Nucleic acid testing for viral burden and viral genotyping

BACKGROUND

Molecular diagnostics plays an important role in the diagnosis and clinical management of a wide array of infectious diseases.

METHODS

Advances in molecular technology and methods of detecting nucleic acid sequences have revolutionized the field of virology. These developments are reflected by the rapid diagnosis and monitoring of viral agents as well as assessment of clinical disease associated with viral infections. In addition to many commercially available molecular based assays, many laboratories offer in-house developed assays for a variety of viral targets. The introduction of real-time PCR technology has made a large impact on virology testing.

CONCLUSIONS

The role of real-time PCR for the diagnosis of viral infections is enhanced by the accuracy, rapidity and ability to quantitate viral target sequences.

Distribution and Prevalence of Human Papillomavirus Genotypes in Routine Pap Smear of 2,470 Korean Women Determined by DNA Chip

Purpose: We examined human papillomavirus (HPV) genotype distribution and prevalence from routine Pap smear cases in Korean women using DNA Chip.

Patients and Methods: A total of 2,470 cervical specimens from women attending routine Pap smear cytology screening in local hospitals was subjected to HPV test. HPV detection and genotyping were done using DNA Chip.

Results: HPV DNA was detected in 44.8% of the patients and in 58.7% of the 861 atypical lesions based on the Bethesda system, including 52.6% of 627 atypical squamous cells of undetermined significance (ASCUS), 69.0% of 168 low-grade squamous intraepithelial lesions (LSIL), and 89.4% of 66 high-grade squamous intraepithelial lesions (HSIL) cases. The most frequently found genotypes in all HPV-positive cases were HPV-16, HPV-52, and HPV-58. HPV-16 was the most prevalent type in within normal limits, ASCUS, and HSIL categories, whereas HPV-51 was most frequently found in LSIL. Multiple infection was identified in about 20% of HPV-positive cases and most of them were that by two different types. HPV-16 was present in the majority of multiple infection cases. A significant decrease in the percentage of multiple infection was observed in HSIL cases compared with ASCUS and LSIL.

Conclusions: The distribution of HPV genotypes in Korean women was revealed to have differences to that of other regions, showing higher frequencies of HPV-52, HPV-58, and HPV-51. HSIL cases were mostly infected by sole HPV-16 whereas LSIL that by various HPV types, suggesting a certain type may become dominant over others as the disease progresses.

Correlation between p14(ARF)/p16(INK4A) expression and HPV infection in uterine cervical cancer

The CDKN2A locus on human chromosome 9p21 encodes two tumor suppressors, p14(ARF) and p16(INK4A), which enhance the growth-suppressive functions of the retinoblastoma (Rb) and the p53 proteins, respectively. Conversely, the E6 and E7 oncoproteins of the high-risk human papillomaviruses (HPVs) causally associated with carcinogenesis of the uterine cervix contributes to tumor development by inactivating p53 and Rb. Nevertheless, a correlation between expression of p14(ARF)/p16(INK4A) and HPV infection in uterine cervix is less clear. To clarify this, we examined 25 cervical cancers and 11 normal uterine cervixes. HPV was detected in 21 of 25 cervical cancers (84%) and their subtype was determined by PCR-RFLP. Quantitative real-time RT-PCR assays showed overexpression of p14(ARF) mRNA in all 21 HPV-positive cases (100%). p16(INK4A) mRNA was overexpressed in 17 cases of the HPV-positive cases (81%). In four HPV-negative cancers, reduced expression of p14(ARF) mRNA was detected in two cases (50%) and reduced p16(INK4A) mRNA in three cases (75%). Our data indicate that the overexpression of p14(ARF) and p16(INK4A) strongly associates with HPV-positive cervical cancers and that reduced expression of p14(ARF) and p16(INK4A) correlates with HPV-negative cervical cancers. These findings may indicate that impaired p14(ARF) and p16(INK4A) mRNA expression contribute to tumor development in HPV-negative cervical cancers by failure to support p53 and Rb instead of their inactivation by HPV E6 and E7.

Detection of Human Papillomavirus DNA and Expression of p16, Rb, and p53 Proteins in Small Cell Carcinomas of the Uterine Cervix

Human papillomavirus (HPV) has been implicated as an etiologic agent for the development of primary small cell carcinoma of the uterine cervix, a rare but highly aggressive malignancy. It has been shown that the HPV E6 and E7 oncoproteins are able to inactivate the tumor suppressor functions of p53 and Rb. In squamous cell carcinoma and adenocarcinoma of the cervix, HPV infection is also associated with overexpression of p16, a cyclin-dependent kinase inhibitor. In this study, 22 cases of primary small cell carcinoma of the uterine cervix were subjected to broad-spectrum HPV DNA amplification and typing, and immunohistochemically examined for the expression of p16, Rb, and p53 proteins. The results show that HPV DNA was detected in every case (100%), with 18 cases (82%) harboring type 18. The tumor cells exhibited strong nuclear staining for p16 in 20 cases (91%). This was associated with a complete loss of Rb nuclear staining in tumor cells in 16 cases (73%). The p53 protein was essentially undetectable in all cases. In contrast, HPV DNA was not detected in 9 colorectal and 8 urinary bladder small cell carcinomas included in this study for comparison. While similar p16 and Rb expression patterns were observed in these HPV-negative tumors, a different expression pattern for p53 was noted where strong nuclear staining was seen in 8 cases (47%; P = 0.0004 compared with cervical tumors). These observations indicate that different mechanisms are involved in the pathogenesis of small cell carcinomas of the uterine cervix and support the notion that nuclear p16 overexpression serves as an indication of Rb defunctioning in tumor cells, which may or may not result from high-risk HPV infection.

Evaluation of p16INK4a and pRb expression in cervical squamous and glandular neoplasia

p16(INK4a) is known to play a critical role as a negative regulator of cell cycle progression and differentiation by controlling the activity of the tumor-suppressor protein pRb. The present study evaluated the expression of p16(INK4a) and pRb in cervical squamous and glandular neoplasia. Immunohistochemical staining was performed for p16(INK4a) and pRb in formalin-fixed, paraffin-embedded tissue sections of the uterine cervix using an indirect immunoperoxidase method. p16(INK4a) staining was detected in 7 of 108 sections (6.5%) of normal squamous mucosa, in scattered ciliated columnar cells in 33 of 88 sections (37.5%) of normal endocervical glands, in 9 of 30 sections (30%) with Nabothian cysts, and in 4 of 4 areas (100%) of tubal metaplasia. In contrast, strong p16(INK4a) staining was found in 13 of 18 cases (72.2%) of cervical intraepithelial neoplasia (CIN) I and in all cases of CIN II/III (n = 46), squamous cell carcinoma (n = 18), endocervical glandular dysplasia (n = 10), adenocarcinoma in situ (n = 23), and invasive adenocarcinoma (n = 12). pRb expression was detected in each diagnostic category; however, the proportion of pRb-positive cells was relatively decreased in high-grade premalignant and malignant lesions of the squamous and endocervical mucosa and showed a generally inverse correlation with the expression of p16(INK4a) at the tissue level. These findings confirm a correlation between the expression of p16(INK4a) and pRb in cervical neoplasias and indicate that p16(INK4a) is a specific marker for premalignant and malignant lesions of the squamous and endocervical mucosa.

The virology of cervical neoplasia: an HPV-associated malignancy

Human papillomaviruses are present in virtually all cervical cancers and cancer precursors. Understanding the epithelial virology of this group of viruses has greatly influenced current concepts of cervical carcinogenesis, has provided a framework for understanding the biologic basis of many diagnostic criteria, and has led to revised classification schemes, diagnostic testing, and modifications in clinical management. This paper briefly reviews virologic concepts supporting the pathogenetic role of these viruses in cervical neoplasia.

P16 as a molecular biomarker of cervical adenocarcinoma

OBJECTIVE

Cervical adenocarcinomas are increasing in incidence each year. The aim of this study was to identify a molecular biomarker to improve early detection.

STUDY DESIGN

Fifty-five in situ and invasive cervical adenocarcinomas were compared with 5 normal endocervical controls by immunohistochemical analysis of p16, p21, p27, cyclin D1, cyclin E, p53, and Ki-67. Expression was scored from 0 to 8 by using an automated imaging system. Western blotting and polymerase chain reaction-based human papillomavirus (HPV) testing were performed on 16 of the invasive cases having fresh-frozen tissue.

RESULTS

P16 exhibited a higher mean expression score for in situ (7.4; P<.0001) and invasive cervical adenocarcinoma (6.6; P<.0001) versus controls (2.0). A cutoff p16 expression score of 5 had a sensitivity of 94.5% and a specificity of 100%. Western blotting confirmed p16 protein expression. Fourteen (88%) of 16 invasive cervical adenocarcinomas were HPV-positive.

CONCLUSION

P16 is a putative molecular biomarker of cervical adenocarcinoma. Overexpression appears to primarily reflect HPV-induced cell cycle dysregulation.

Epidemiological and clinical aspects of human papillomavirus detection in the prevention of cervical cancer

Cervical cancer is a major cause of death, and the second most frequent cancer in women worldwide. Many studies have indicated a causal relation between genital human papillomavirus (HPV) infections and cervical cancer. High-risk HPV genotypes have been detected in almost 100% of all cervical cancers, and the process of HPV mediated carcinogenesis has been partly clarified. The concept that HPV is a obligatory cause in cervical cancer development has lead to extensive research regarding the incorporation of HPV detection in (1) cervical cancer prevention programs, (2) triage of women with abnormal cervical scrapes in the screening program, and (3) follow-up of patients treated for cervical intraepithelial neoplasia (CIN). Epidemiological studies indicate that 50% of women becoming sexually active contract a genital HPV infection within 2 years. The lifetime risk of a genital HPV infection is estimated to be 80%, but very few of these women will develop cervical cancer. Several studies have shown that the persistence of genital HPV infections is especially related to the development of cervical cancer. As a result, HPV detection at a single moment was shown to be of limited clinical value in the triage of patients with abnormal cervical scrapes, or during follow-up after treatment for CIN. Furthermore, major variations in the sensitivity of different HPV detection methods, as well as differences in HPV detection related to the menstrual cycle, have shown that many facts regarding HPV transmission, replication, and detection need to be clarified, before HPV detection can be of clinical value.

Human papillomavirus (HPV) education in middle and high schools of Vermont

Human papillomavirus (HPV), the most prevalent sexually transmitted disease (STD), continues to pose a significant public health problem especially among the adolescent population. Most precancerous and cancerous cervical changes are associated with HPV, with adolescent women being biologically at highest risk for acquiring HPV. This survey examined the type of information taught to adolescents about HPV, and specific needs for effective HPV education in middle and high schools in Vermont. The survey addressed knowledge level, behavior, attitudes, enabling factors, motivators, and barriers. Data were analyzed by descriptive statistics and supplemented with contingency table analyses. Replies (n = 108) were received from 79 schools, with 60% of responses from nurses and 40% from teachers. In five of eight questions addressing basic knowledge of HPV, less than 60% of respondents gave the correct answer. Most (73%) felt it was important to teach about HPV relative to HIV/AIDS, but spent less classroom time teaching it. Main motivations for teaching about HPV were its importance, and a desire to increase student knowledge and prevention skills. Main barriers perceived were lack of time and materials and curricula, and need for more knowledge about HPV. The most prominent needs indicated included brochures for students, an increase in the educators' knowledge base, and a high school curriculum. Health educators in Vermont schools recognize the importance of teaching adolescents about HPV, but they lack basic knowledge and resources for teaching about HPV.

P16 and p53 Expression in (Pre)Malignant Epidermal Tumors of Renal Transplant Recipients and Immunocompetent Individuals

Ultraviolet (UV) radiation is a prevailing factor implicated in the etiology of keratinocytic intraepidermal neoplasia (KIN) and squamous cell carcinomas (SCCs), as evidenced by the high frequency of UV-related mutations in the p53 and p16 tumor suppressor genes. In renal transplant recipients (RTRs), immunosuppression is considered another important risk factor in the enhanced carcinogenesis in these patients. So far, effects of UV and immune status on p53 and p16 immunoexpression in SCCs and precursors have not been studied. The aims of this study were to assess (1) the relation between risk factors for carcinogenesis, sun exposure and immune status, and p16 or p53 expression, and (2) to assess differences in p16 and p53 expression between KINs and SCCs. Immunostaining for p16 and p53 was performed on paraffin-embedded sections of 23 low-grade KIN (LKIN) lesions, 28 high-grade KINs (HKINs), and 35 SCCs from 44 RTRs and 42 immunocompetent controls (ICIs). In 74/86 lesions (86%), p53 was expressed, and in 63/86 (76%) lesions, p16 expression was present. Negativity for both p16 and p53 was found in 4/86 (5%) cases, whereas combined p53/p16 staining was most prevalent (55/86 lesions, 64%). P16 staining proved independent of p53 expression (P =.8), and immune status, sun exposure, and histological diagnosis (LKIN-HKIN-SCC) had no influence on this independence. Transplantation was associated with p53 expression in SCCs (P =.02; power = 34%) caused by higher prevalence of p53-negative SCCs in RTRs than in ICIs (30% versus 0). In HKINs, p16 was more frequently positive than in LKINs (P =.003; power = 49%) and SCCs (P =.03; power = 53%). HKINs showed more frequent transepidermal p16 and p53 staining than LKIN lesions (P <.001; power >/= 99%). This study demonstrates that in KIN lesions and cutaneous SCCs, p16 expression is independent of p53 expression, and immune status, sun exposure, and histological diagnosis have no influence on this independence. Furthermore, HKIN lesions express significantly more p16 than LKINs and SCCs.

Suppression of human papillomavirus gene expression in vitro and in vivo by herpes simplex virus type 2 infection

Recent epidemiological studies have found that women infected with both herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) type 16 or HPV-18 are at greater risk of developing cervical carcinoma compared to women infected with only one virus. However, it remains unclear if HSV-2 is a cofactor for cervical cancer or if HPV and HSV-2 interact in any way. We have studied the effect of HSV-2 infection on HPV-11 gene expression in an in vitro double-infection assay. HPV transcripts were down-regulated in response to HSV-2 infection. Two HSV-2 vhs mutants failed to reduce HPV-16 E1;E4 transcripts. We also studied the effect of HSV-2 infection on preexisting experimental papillomas in a vaginal epithelial xenograft model. Doubly infected grafts demonstrated papillomatous transformation and the classical cytopathic effect from HSV-2 infection. HPV and HSV DNA signals were mutually exclusive. These studies may have therapeutic applications for HPV infections and related neoplasms.

Human papillomavirus infection and p53 protein expression in vulvar intraepithelial neoplasia and invasive squamous cell carcinoma

The etiopathogenesis of vulvar intraepithelial neoplasia (VIN III) and invasive squamous cell carcinoma are largely unknown. Since there are few studies on Brazilian patients, our purpose was to determine the frequency of human papillomavirus (HPV) infection and the expression of p53 in these lesions, and associate them with other factors such as age, morphological subtypes, multicentric and multifocal disease. Thirty-eight cases of VIN III, nine of superficially invasive carcinoma, and 55 of invasive vulvar carcinoma were retrospectively evaluated from 1983 to 1995 for the presence of HPV by immunohistochemistry and in situ hybridization, and for p53 protein expression by immunohistochemistry on paraffin sections. All cases for whom material (slides and paraffin blocks) and clinical data were available were included. HPV and p53 were detected in 57.9 and 21.1% of the VIN III lesions, 33.3 and 66.7% of superficially invasive carcinomas, and 7.3 and 58.2% of invasive squamous cell carcinomas, respectively. HPV infection was associated with younger age in the VIN III and invasive carcinoma groups. In the latter, HPV infection was associated with the basaloid variant. p53 expression rate was higher in superficially invasive and invasive lesions and was not related to HPV infection. Our findings are similar to others and support the hypothesis that there are two separate entities of the disease, one associated with HPV and the other unrelated, with p53 inactivation possibly being implicated in some of the cases.

Human papillomavirus biology and cervical neoplasia: implications for diagnostic criteria and testing

Human papillomaviruses are necessary for the development of cervical neoplasia. Progress in our understanding of the epithelial biology of this common pathogen has greatly influenced current concepts of cervical carcinogenesis. This understanding has provided a framework for understanding the biologic basis of many diagnostic criteria. Furthermore, classification schemes, diagnostic testing, and clinical management have been modified and clarified in light of this knowledge.

Interplay between human papillomaviruses and dendritic cells

The design of the human papillomavirus (HPV) infection cycle is tightly fitted to the differentiation program of its natural host, the keratinocyte. This has important consequences for the role of antigen-presenting cells in the priming of antiviral immunity. The confinement of HPV infection to epithelia puts the epithelial dendritic cell, the Langerhans cell (LC), in charge of the induction of T cell-dependent immunity. Because HPV-infected keratinocytes cannot reach the regional lymphoid organs, and HPV-infection of LCs does not result in viral gene expression, priming of antiviral T cells exclusively depends on cross-presentation of viral antigens by the LC. Sensitization of the immune system in the regional lymphoid organs elicits systemic anti-HPV immunity as well as intraepithelial immune surveillance by memory-type intraepithelial T cells and locally produced antibodies. The high rate of spontaneous rejections of high-risk HPV-infections and HPV-positive premalignant lesions indicates that in general the LC-driven antigen presentation machinery is capable of raising an effective immune defense against HPV. Epidemiological studies also reveal that a decrease in the vigilance of the immune system is readily exploited by HPV to escape immune destruction, resulting in persistent infections and development of HPV-positive cancers. In view of the inherent antigenicity of HPV, immune intervention strategies constitute a promising approach for both the prevention and the therapeutic treatment of HPV-induced diseases. Importantly, the mechanisms that govern the induction and effector phases of the intraepithelial immune surveillance against HPV must be taken into account when designing such strategies.

Viruses and neoplastic growth

At present, information concerning the role of viruses in the pathogenesis of human neoplasms is fragmented and incomplete. It is clear that their role is complex, and a complete understanding of the intricacies involved in viral interaction with the human genome may still take many years. New virologic study techniques can be expected to emerge and epidemiologic studies will continue. With each new report, a bit more will be understood, new hypotheses stimulated, and additional studies undertaken. The identification of viral agents as causative agents of neoplasia and the pathogenetic mechanisms by which they act will have a profound effect on our approaches to oral cancer.

Biology and evolution of cervical squamous intraepithelial lesions: a hypothesis with diagnostic prognostic implications

Recent advances in the understanding of HPV-associated cervical squamous intraepithelial lesions, specifically with respect to HPV DNA integration into basal cervical epithelial cells, need to be incorporated into strategies for diagnosing and classifying these lesions. The biology and evolution of HPV-associated cervical squamous intraepithelial lesions is reviewed, along with recent developments using tyramide-based in situ hybridization and MIB-1 immunoreactivity. It is proposed that HPV DNA integration into the basal cells of cervical squamous epithelium precedes the transformation of low-into high-grade lesions. The HPV DNA tyramide-based in situ hybridization system may prove to be a powerful diagnostic/prognostic tool in this regard. It is also proposed that the presence of mitoses (especially atypical forms) in the upper layers may be a discriminatory hallmark in the morphologic distinction between low- and high-grade lesions. Further, since the biologic changes manifest between these two lesions are reflected in their respective phenotype, it appears plausible to adopt the Bethesda System two-tiered/binary classification of LGSIL and HGSIL for histopathologic diagnoses.

Reflex human papillomavirus DNA testing on residual liquid-based (TPPT) cervical samples: focus on age-stratified clinical performance

BACKGROUND

Liquid-based ThinPrep technology has made reflex human papillomavirus (HPV) DNA testing possible. In the current study, the clinical performance of reflex HPV testing as an adjunct to routine ThinPrep testing (TPPT) and the impact of age on various test parameters in a predominantly high-risk, minority population were evaluated retrospectively.

METHODS

Reflex HPV testing was performed in 2114 women with atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cytology, using probes for low-risk (LR) and high-risk (HR) HPV types. Six hundred thirty women underwent subsequent biopsies with which HPV testing results were correlated.

RESULTS

Approximately 86% of the patients were Hispanic and African-American and 12% were white. Of the younger women (ages 14-29 years), 81% were positive for HR types versus 50% in the older women (ages 30-77 years) (P < 0.0001). In women with ASCUS, 47% were found to be positive for HR types versus 78% of women with LSIL. The percentage of histologic high-grade lesions was 24% in younger patients versus 17% in older patients. Overall, 91% of high-grade lesions were positive for HPV DNA (HR-positive = 89% and LR-positive = 2%), and 9% were negative for both types. The sensitivities and specificities in "younger" versus "older" women were 92% (95% confidence interval [95% CI], 89-95%) and 22%% (95% CI, 17-26%), respectively, versus 84% (95% CI, 77-90%) and 59% (95% CI, 53-65%), respectively.

CONCLUSIONS

The results of the current study demonstrate that reflex HPV testing performed in a routine clinical practice helps to identify the majority of women with high-grade disease. However, testing may be more beneficial in older women (age > or = 30 years) with ASCUS. Strategy using out-of-vial reflex testing is more cost-effective and sensitive than referring all women for colposcopies.

Non-acquired immunodeficiency syndrome-defining malignancies in patients infected with human immunodeficiency virus

CONTEXT

Non-acquired immunodeficiency syndrome (AIDS)-defining malignancies that occur in patients infected with human immunodeficiency virus (HIV) and the demographics and pathologic features associated with these malignancies have not been completely defined.

OBJECTIVE

This study describes the age of onset of malignant disease in patients seropositive for HIV and in control patients presumed to be negative for HIV, but with the same primary site. We compare the demographics and histopathology for both groups.

DESIGN

From 1993 to 1997, 57 cases involving HIV-positive patients with malignancies from 16 primary sites were recorded in the Cancer Registry files at Bellevue Hospital; 519 cases involving patients negative for HIV were recorded during this same period. We compared the age at diagnosis, sex, race, tumor histology, stage, and grade between these 2 groups.

RESULTS

The average age of HIV-positive patients was 47.6 years, compared with 60.3 years in the control group (P <.001). When the 16 cancer sites were compared individually, HIV-positive patients were significantly younger at onset of lung (HIV-positive patients/control group) (19/245), skin (11/77), penile (3/5), laryngeal (3/18), tongue (5/16), and colorectal (2/38) carcinomas. Patients infected with HIV had a more frequent history of smoking (41/328; P =.04) and illicit drug use (30/49; P <.001). The HIV-positive patients also were found to have a lower clinical stage of disease, compared with controls, largely due to the higher prevalence of stage 0 tumors (13/46; P =.01).

CONCLUSIONS

The finding of younger age at diagnosis in HIV-positive compared to presumed HIV-negative patients may be related in part to earlier detection, as well as preexisting immunosuppression. The specific sites for which a significant difference in age between the HIV-positive and control cases was observed may be related to the mechanisms of immunosurveillance in parts of the body that have ready access to the outside environment. Knowledge of younger age of onset for these malignancies should prompt closer physical examination of these sites by clinicians.

Insertion of a foreign sequence on capsid surface loops of human papillomavirus type 16 virus-like particles reduces their capacity to induce neutralizing antibodies and delineates a conformational neutralizing epitope

The aims of this study were to generate chimeric human papillomavirus (HPV)-16 L1 virus-like particles (VLPs) in order to identify immunogenic domains and conformational neutralizing epitopes, and to characterize the regions where a foreign epitope could be introduced. We hypothesized that these regions could be on L1 protein loops since they are exposed on the surface of VLPs. The aims of this study were achieved by mutating HPV-16 L1 proteins. Six amino acids encoding for the epitope 78-83 (DPASRE) of the hepatitis B core (HBc) antigen were introduced within the different loops of the L1 protein at positions 56/57, 140/141, 179/180, 266/267, 283/284 or 352/353. All these chimeric L1 proteins were capable of self-assembly into VLPs. The antigenicity and immunogenicity of some of these VLPs were reduced compared to the levels observed with wild-type VLPs. All were nevertheless able to induce neutralizing antibodies. VLPs with insertion at position 266/267 induced lower levels of neutralizing antibodies, suggesting the involvement of residues situated on FG loop in L1 neutralizing epitopes. All the chimeric L1 proteins except the one with insertion at position 56/57 were also able to induce anti-HBc antibodies, thus suggesting exposure of the HBc epitope on the VLP surface. Taken together, our findings indicate the possibility of designing HPV-derived vectors that are less immunogenic and suggest positions for insertion of defined immune epitopes or cell ligands into L1 protein to be exposed on the surface of VLPs.

The novel human MOST-1 (C8orf17) gene exhibits tissue specific expression, maps to chromosome 8q24.2, and is overexpressed/amplified in high grade cancers of the breast and prostate

AIMS

To elucidate genes that participate in the process of oncogenesis, primers based on the E6 genes of genital human papillomaviruses (HPVs) were used to amplify potential expressed sequence tags (ESTs) from the MOLT-4 T lymphoblastic leukaemia cell line.

METHODS

Using the polymerase chain reaction (PCR) with human papillomavirus E6 gene primers, an EST from the MOLT-4 T lymphoblastic leukaemia cell line was amplified. Via rapid amplification of cDNA ends (RACE) and cycle sequencing from MOLT-4 and fetal lung cDNA libraries, overlapping cDNAs of 2786 bp and 2054 bp of the corresponding novel human intronless gene designated MOST-1 (for MOLT-4 sequence tag-1) were characterised and assigned the symbol C8orf17 by the HUGO Nomenclature Committee.

RESULTS

Both cDNAs contained a potential open reading frame (ORF) of 297 bp incorporating a methionine codon with an ideal Kozak consensus sequence for translation initiation, and encoding a putative hydrophilic polypeptide of 99 amino acids. Although reverse transcription PCR (RT-PCR) demonstrated MOST-1 expression in all 19 cancer and two normal cell lines tested, differential expression was seen in only nine of 16 normal tissues tested (heart, kidney, liver, pancreas, small intestine, ovary, testis, prostate, and thymus). A 388 bp fragment was amplified from the NS-1 mouse myeloma cell line, the sequence of which was identical to that within the MOST-1 ORF. The MOST-1 gene was mapped by fluorescent in situ hybridisation to chromosome 8q24.2, a region amplified in many breast cancers and prostate cancers, which is also the candidate site of potential oncogene(s) other than c-myc located at 8q24.1. Analysis of paired biopsies of invasive ductal breast cancer and adjacent normal tissue by semiquantitative and real time RT-PCR revealed average tumour to normal ratios of MOST-1 expression that were two times greater in grade 3 cancers than in grade 1 and 2 cancers. Quantitative real time PCR of archival prostatic biopsies displayed MOST-1 DNA values that were 9.9, 7.5, 4.2, and 1.4 times higher in high grade carcinomas, intermediate grade carcinomas, low grade carcinomas, and benign hyperplasias, respectively, than in normal samples.

CONCLUSIONS

These data suggest a role for MOST-1 in cellular differentiation, proliferation, and carcinogenesis.

Symposium part 4: Should pathologists diagnose endocervical preneoplastic lesions "less than" adenocarcinoma in situ?: Counterpoint

Adenocarcinoma in situ (AIS) is the acknowledged precursor to most cases of invasive adenocarcinoma of the cervix. However, diagnostic terminology for lesions that do not fulfill all of the published criteria for AIS has not been standardized. Some have used the terms "glandular dysplasia" or " atypical hyperplasia" for purported antecedents of AIS, whereas others have adopted the term "cervical intraepithelial glandular neoplasia" (CIGN) for the entire spectrum of endocervical atypicality including AIS, with subcategories of "low-grade" and "high-grade" CIGN. In this article the appropriateness of using these terms in diagnostic reports (versus the use of AIS to include some or most of the lesions encompassed by them, with nonspecific terminology for the remainder) is examined in the light of the relevant objective studies bearing on this question. An opinion is offered favoring the latter approach.