Difference in prevalence of human papillomavirus genotypes in cytomorphologically normal cervical smears is associated with a history of cervical intraepithelial neoplasia

Impact of HPV testing in opportunistic cervical screening: Support for primary HPV screening in the United States

Human papillomavirus (HPV) testing for cervical screening increases diagnosis of precancer and reduces the incidence of cervical cancer more than cytology alone. However, real-world evidence from diverse practice settings is lacking for the United States (U.S.) to support clinician adoption of primary HPV screening. Using a population-based registry, which captures all cervical cytology (with or without HPV testing) and all cervical biopsies, we conducted a real-world evidence study of screening in women aged 30 to 64 years across the entire state of New Mexico. Negative cytology was used to distinguish cotests from reflex HPV tests. A total of 264 198 cervical screening tests (with exclusions based on clinical history) were recorded as the first screening test between 2014 and 2017. Diagnoses of cervical intraepithelial neoplasia grades 2 or 3 or greater (CIN2+, CIN3+) from 2014 to 2019 were the main outcomes. Of cytology-negative screens, 165 595 (67.1%) were cotests and 4.8% of these led to biopsy within 2 years vs 3.2% in the cytology-only group. Among cytology-negative, HPV tested women, 347 of 398 (87.2%) CIN2+ cases were diagnosed in HPV-positive women, as were 147 of 164 (89.6%) CIN3+ cases. Only 29/921 (3.2%) CIN3+ and 67/1964 (3.4%) CIN2+ cases were diagnosed in HPV-negative, cytology-positive women with biopsies. Under U.S. opportunistic screening, across a diversity of health care delivery practices, and in a population suffering multiple disparities, we show adding HPV testing to cytology substantially increased the yield of CIN2+ and CIN3+. CIN3+ was rarely diagnosed in HPV-negative women with abnormal cytology, supporting U.S. primary HPV-only screening.

Molecular mechanisms of the preventable causes of cancer in the United States

Annually, there are 1.6 million new cases of cancer and nearly 600,000 cancer deaths in the United States alone. The public health burden associated with these numbers has motivated enormous research efforts into understanding the root causes of cancer. These efforts have led to the recognition that between 40% and 45% of cancers are associated with preventable risk factors and, importantly, have identified specific molecular mechanisms by which these exposures modify human physiology to induce or promote cancer. The increasingly refined knowledge of these mechanisms, which we summarize here, emphasizes the need for greater efforts toward primary cancer prevention through mitigation of modifiable risk factors. It also suggests exploitable avenues for improved secondary prevention (which includes the development of therapeutics designed for cancer interception and enhanced techniques for noninvasive screening and early detection) based on detailed knowledge of early neoplastic pathobiology. Such efforts would complement the current emphasis on the development of therapeutic approaches to treat established cancers and are likely to result in far greater gains in reducing morbidity and mortality.

Comparison between L and E gene amplification analytical methods for human papillomavirus typing

OBJECTIVE

L and E6/E7 gene amplification analyses were compared to identify human papillomavirus (HPV) infection and verify the HPV type, with the intent to minimize HPV typing errors.

METHODS

L1 gene verified HPV typing was accomplished via polymerase chain reaction (PCR) and membrane assays. Verification of HPV typing via E6/E7 genes was accomplished through nested multiplexed PCR. The results from 104 samples were compared.

RESULTS

The rates of accordance and difference were 35% and 65%, respectively. For 29% of the analyses, nested multiplexed PCR was more diversified than the membrane assay.

CONCLUSION

HPV can be classified into low-risk HPV and high-risk HPV groups. In parallel amplifications of the L and E genes is more efficient for accurate diagnosis in light of the different symptoms and attendant precautions of the risk groups.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

Human papillomavirus and pterygium. Is the virus a risk factor?

BACKGROUND

Pterygium is a disease of unknown origin and pathogenesis that might be vision threatening. It is characterised by a wing-like conjunctival overgrowth of the cornea. Several studies have investigated human papillomavirus (HPV) as a risk factor for the development of pterygia, but the results are inconclusive.

AIM

To investigate a large sample of pterygia for the presence of HPV in order to clarify the putative association between pterygia and HPV.

METHODS

100 specimens of pterygium from Danish patients and 20 normal conjunctival biopsy specimens were investigated for the presence of HPV with PCR technique using beta-globin primers to access the quality of the extracted DNA and the HPV primers MY09/11 and GP5+/6+. HPV-positive specimens underwent subsequent HPV typing with type-specific HPV primers and further investigation with DNA in situ hybridisation (ISH).

RESULTS

90 of 100 investigated pterygia proved suitable for HPV analysis by PCR. As beta-globin could not be amplified, 10 specimens were excluded from the study. 4 of 90 pterygia harboured HPV. HPV type 6 was identified in all four HPV-positive pterygia. The 20 normal conjunctival biopsy specimens were beta-globin positive and HPV negative. All four pterygia that were HPV type 6 positive were DNA ISH negative.

CONCLUSIONS

The low presence of HPV DNA in pterygia does not support the hypothesis that HPV is involved in the development of pterygia in Denmark.

Telomerase activity as an adjunct to high-risk human papillomavirus types 16 and 18 and cytology screening in cervical cancer

Telomerase is a ribonucleoprotein comprising an RNA template, the telomerase-associated protein and its catalytic subunit, human telomerase reverse transcriptase (hTERT). Telomerase activation is a critical step in cellular immortalisation and development of cancer. Enhanced telomerase activity has been demonstrated in cervical cancer. In the present study telomerase activity and hTERT mRNA expression were evaluated and correlated with the presence of human papillomavirus (HPV) infection and cytological changes in the cervical lesions. Telomerase activity was assayed by telomeric repeat amplification protocol, hTERT mRNA expression by reverse transcriptase polymerase chain reaction and presence of high risk HPV (HR-HPV) infection by polymerase chain reaction. Out of 154 cervical samples of different cytology, 90 (58.44%) were positive for HR-HPV types 16/18, while among 55 normal cervical scrapes, 10 (18.18%) were HPV DNA positive. All 59 invasive cancer samples showed a very high telomerase activity. Among dysplasia, seven (63.6%) mild dysplasia, 18 (100%) of moderate, 20 (100%) of severe dysplasia and 6 (100%) carcinoma in situ (CIS) samples were positive with mild to moderate to high to very high telomerase activity respectively. Seven (12.7%) samples of apparently normal cervical scrapes were weakly positive for telomerase activity. We observed a good correlation (P<0.001) between telomerase activity and HR-HPV 16/18 positivity with a sensitivity of 88.1% for HPV and 100% for telomerase activity. It is suggested that telomerase activity may be used as an adjunct to cytology and HPV DNA testing in triaging women with cervical lesions.

Semiquantitative analysis of human papillomavirus DNA in cervical intraepithelial neoplasia by a differential polymerase chain reaction

A differential polymerase chain reaction (PCR), which takes account of both the human papillomavirus (HPV) type and the amount of viral DNA, was applied to 100 cervical intraepithelial neoplasias (CIN) in order to improve the characterisation of the lesions. One hundred women with cytological smears suggestive of CIN I-III and a colposcopically guided punch biopsy were studied. DNA was phenol-extracted and a consensus PCR with L1 primers and a type-specific PCR for HPV-16 and-18 E6 were performed in parallel. The different sensitivity of the PCR methods allowed a semiquantitative analysis of viral DNA. HPV analysis was possible in all 100 very small cervical punch biopsies. Of the lesions 79% were HPVpositive. The percentage of HPV-16-positive lesions increased significantly (P < 0.001) with the degree of severity of CIN (CIN I: 46%, CIN II: 63%, CIN III: 85%). The percentage of CIN with a high viral load increased also with the grade of CIN (CIN I: 8%, CIN II: 33%, CIN III: 44%). Cytologically positive lesions (Pap IIID or IVa) had significantly more frequently (p < 0.02) a high viral load: 39% vs. 10% of cytologically false negative lesions. In conclusion, type-specific PCR had a very high sensitivity in the detection of HPV-DNA also in cytologically false negative CIN. The addition of the less sensitive consensusPCR allowed a semiquantitative analysis of the viral copy number. The higher amount of viral DNA in cytologically positive lesions, which may correspond to a higher rate of proliferation, reflects a possible role of the viral load in the progression of CIN. In clinical practice, differential HPVPCR could help to improve the management of CIN.

Analysis of human papillomavirus type-16 variants in Italian women with cervical intraepithelial neoplasia and cervical cancer

Human papillomavirus type 16 (HPV-16) classes (E, AA, As, Af1, Af2) and their variants have different geographic distribution and different degrees of association with cervical lesions. This study was designed to examine HPV-16 variants among Italian women and their prevalence in case patients (affected by invasive cervical carcinoma or cervical intraepithelial neoplasia grade 2-3 and cervical intraepithelial neoplasia grade 1), versus control subjects with normal cervical epithelium (controls). A total of 90 HPV-16 positive cervical samples from women of Italian Caucasian descent have been tested, including 36 invasive cervical carcinomas, 21 with cervical intraepithelial neoplasias grade 2-3, 17 with cervical intraepithelial neoplasia grade 1 and 16 controls. HPV-16 was detected with an E6/E7 gene-specific polymerase chain reaction, and variant HPV-16 classes and subclasses were identified by direct nucleotide sequencing of the region coding for the E6 and the E7 oncoproteins, the MY09/11-amplified highly conserved L1 region, and the long control region (LCR). Among the 90 HPV-16 samples, nine viral variants have been identified belonging to the European (Ep-T350 and E-G350) and non-European (AA and Af-1) branches. The E-G350 is the prevalent variant in all analyzed different disease stages being present in 55.5% of ICC, 52.4% of cervical intraepithelial neoplasias 2-3, 47.1% of cervical intraepithelial neoplasia grade 1, and 50.0% of control samples. The non-European variants AA and Af1, rarely detected in control samples, represent 33.3% of all HPV-16 infections in invasive cervical carcinoma (with a peak of 19.4% and 13.9%, respectively), showing a statistically significant increase in frequency in more advanced lesions (chi(2) trend = 7.2; P < 0.05). The prevalence of HPV-16 Ep-T350, however, is higher in controls (43.7%) and in of cervical intraepithelial neoplasia grade 1 (41.2%) than in cervical intraepithelial neoplasia grade 2-3 (28.6%) and in invasive cervical carcinoma (11.1%) cases strongly suggesting lack of progression for pre-neoplastic lesions associated with such variant. The increased frequency of non-European variants in invasive lesions suggests that they are more oncogenic than European variants. This could have implications for future diagnostic and therapeutic strategies.

Human papilloma virus type 16 infection and the early onset of cervical cancer

Human papilloma viruses (HPV), particularly type 16, have been associated with cervical cancer. It has been noted that the average onset of cervical cancer is occurring in younger women coupled with a higher prevalence of cervical HPV infection. However, the correlation between HPV 16 infection and the early onset of cervical cancer is still unclear. We hypothesize that HPV infection is an indicator of early onset of cervical cancer. To test this hypothesis, cervical smears from 197 women were evaluated by the polymerase chain reaction for HPV 16. These data revealed that the HPV 16-positive women were significantly younger than the HPV 16-negative women. Moreover, the average age of HPV 16-positive women with CIN 3 or invasive cancer was significantly younger compared with the other groups. These data clearly suggest that HPV 16 infection is a significant risk factor for the progression for cervical cancer in a young population of women.

Adding HPV16 testing to abnormal cervical smear detection is useful for predicting CIN3: a prospective study

BACKGROUND

The aim of this prospective study was to estimate whether adding human papillomavirus 16 (HPV16) testing to abnormal cervical smears is useful in the prediction of cervical intraepithelial neoplasia 3 (CIN3).

METHODS

Between October 1994 and May 1996, a total of 207 patients at the Akita University Hospital had abnormal smears. Of these patients, 153 patients with CIN1,2 or atypical squamous cells of undetermined significance (ASCUS) were enrolled in this study and followed until June 2001. At the initial visit, a cervical swab was collected for cytology and for HPV16 testing using nested polymerase chain reaction (PCR). When the HPV16 test was positive, HPV16 testing was performed every 3 to 6 months. We compared the prevalence of progression to CIN3 between the HPV16-positive group (n = 16) and the HPV16-negative group (n = 137). We also investigated the risk of progression to CIN3 associated with persistent HPV16 infection.

RESULTS

At the end of the study period, four patients (25%) in the HPV16-positive group developed CIN3, and all of these patients were found to have persistent HPV16 infection during this period. Only three patients (2.2%) in the HPV16-negative group developed CIN3.

CONCLUSIONS

The prevalence of progression to CIN3 in the HPV16-positive group was significantly higher than that in the negative group (p = 0.0023). The odds ratio of progression to CIN3 was 14.9 [95% confidence interval (CI) 2.98-74.4]. In particular, the risk of progression to CIN3 increased with persistent HPV16 infection. Adding HPV16 testing when abnormal cervical smears are detected promises to be useful for predicting CIN3.

Characterization of human papillomavirus infection, P53 and Ki-67 expression in cervix cancer of Mozambican women

In this study, we aimed at evaluating the distribution of HPV types and the expression of P53 and Ki-67 in cervix carcinomas of Mozambican women. Fourty-seven invasive carcinomas, 10 CIN III, and 10 normal cervix were studied. P53 and Ki-67 expression was examined immunohistochemically. HPV infection and HPV types were detected by PCR (GP5+/bio-GP6+) and enzyme-immunoassay, respectively. Expression of P53 and Ki-67 and detection of HPV were as follows: normal cervix--0%, 10%, and 0%, respectively; CIN III--10%, 0%, and 100%, respectively; invasive carcinomas--50%, 55.5%, and 70%, respectively. HPV 16 was identified in 54% of invasive carcinomas, HPV 31, 33, 35, and 45 in 23%, "unidentified" HPV in 19%, and HPV 18 in 4% of invasive carcinomas. No significant associations were observed between P53 expression, Ki-67 expression, and HPV infection. In conclusion, we observed a high frequency of HPV infection in CIN III lesions and invasive carcinomas from Mozambican women, with HPV 16 representing the most frequent viral type. HPV status was not related to P53 and Ki-67 expression. Both P53 and Ki-67 are associated with invasive cervix carcinomas, mainly of the squamous keratinizing histotype.

Prospective study on cervical neoplasia: presence of HPV DNA in cytological smears precedes the development of cervical neoplastic lesions

OBJECTIVES

The principal aim of the study was to verify whether HPV infection in healthy women, as determined by HPV DNA detection, was associated with an increased risk of development of cervical lesions.

METHODS

Cervical smears collected at enrolment into the prospective study conducted in Prague during 1975-83 were tested for the presence of HPV DNA by means of a polymerase chain reaction (PCR) using the general GP5/6 primers and a mixture of primers specific for the E6 gene. 120 smears from patients in whom cervical neoplasia had been detected in the course of the prospective study and 208 smears from control women who had remained healthy throughout the observation period were analysed. Patients and controls were matched by age, number of sexual partners, age at first intercourse, and smoking habit. Patients were divided into three groups, A, B, and C, according to their cytological, colposcopic, and histological findings at enrolment. Group A consisted of 67 women found ill at enrolment, group B of 26 women with slightly suspicious findings, while group C comprised 27 women with normal findings at enrolment. In addition, sera taken at enrolment from these patients and controls were tested for the presence of antibodies reactive with virus-like particles (VLPs) of HPV 16, 18, and 33.

RESULTS

For the whole cohort, there was a statistically highly significant difference in the presence of HPV DNA between patients and controls. Furthermore, the difference in the presence of HPV DNA between patients and controls was highly significant not only in those who had been found ill at enrolment (group A) but, most importantly, also in women who had developed the disease in the course of the follow up (groups B and C). Women positive for HPV DNA possessed HPV antibodies to VLP16, 18 and 33 significantly more often than those who were free of HPV DNA.

CONCLUSION

This indicated that healthy women who were positive for HPV DNA at enrolment were at an increased risk of developing cervical neoplasia (OR = 18.5; CI 5.9 to 57.6).

Human papillomavirus type 16 status in cervical carcinoma cell DNA assayed by multiplex PCR

Integration of human papillomavirus (HPV) DNA into host genome occurs early in cancer development and is probably an important event in malignant transformation of cervical cancer. The HPV genome integration usually disrupts E2 gene open reading frames. It results in the lack of E2 gene suppressor of the synthesis of E6 and E7 products which, in turn, leads to the overexpression of E6 and E7 genes. The oncogenic HPV types (HPV16, -18, -45, and -58) can be present as episomes or may integrate into human chromosomes. Sixty-six cervical cancer patients positive for HPV16 were tested for the presence of E6, E2, E1, and L1 genes. Multiplex PCR was carried out in all cases. Using cluster analysis, the calculated ratios of E1/E6, E2/E6, L1/E6, E1/E2, and E2/(E1*E6) gene amplification products were divided into two or three statistically different groups. These were used for statistical analysis of the prevalence of specific gene types in histological types of cancer, different levels of clinical staging, and histologically confirmed nodal metastases. The statistical analysis proved a significant correlation in the ratios of E2/E6 and E1/E2 only. The E2/E6 and E1/E2 were higher in carcinoma in situ than in advanced squamous cancers. The E2/E6 ratios were lower in higher clinical stages. The multiplex PCR estimation of the E2/E6 ratio could be a simple method for selecting patients with a high risk of a poor outcome in a standard stage-dependent treatment procedure.

Prevalence and determinants of HPV infection among Colombian women with normal cytology

Human papillomavirus is the principal risk factor associated with cervical cancer, the most common malignancy among women in Colombia. We conducted a survey, aiming to report type specific prevalence and determinants of human papillomavirus infection in women with normal cytology. A total of 1859 women from Bogota, Colombia were interviewed and tested for human papillomavirus using a general primer GP5+/GP6+ mediated PCR-EIA. The overall HPV DNA prevalence was 14.8%; 9% of the women were infected by high risk types, 3.1% by low risk types, 2.3% by both high risk/low risk types and 0.4% by uncharacterized types (human papillomavirus X). Thirty-two different human papillomavirus types were detected, being human papillomavirus 16, 58, 56, 81(CP8304) and 18 the most common types. The human papillomavirus prevalence was 26.1% among women younger than 20 years, 2.3% in women aged 45-54 years, and 13.2% in women aged 55 years or more. For low risk types the highest peak of prevalence was observed in women aged 55 years or more. Compared to women aged 35-44 years, women aged less than 20 years had a 10-fold increased risk of having multiple infections. Besides age, there was a positive association between the risk of human papillomavirus infection and number of regular sexual partners and oral contraceptive use. In women aged below 25 years, high educational level and having had casual sexual partners predicted infection risk. In conclusion, there was a broad diversity of human papillomavirus infections with high risk types being the most common types detected. In this population multiplicity of sexual partners and, among young women, high educational level and casual sexual partners seem to determine risk.

Detection of human papillomavirus (HPV) genotypes in cervico-vaginal scrapes of women with normal and abnormal cytology

BACKGROUND

Certain types of human papillomavirus (HPV) are associated with cervical intraepithelial neoplasia (CIN) and invasive cervical carcinoma. The study addressed the expression and detection of HPV genotypes in cervical and vaginal specimens of women with normal and abnormal cytology by polymerase chain reaction (PCR), each woman serving as her own control.

METHODS

Study participants (127) were subgrouped into CIN-positive and CIN-negative, based on cytology screening, and endocervical and vaginal scrapes were collected by a gynecologist and placed immediately in saline. HPV DNA was assessed by PCR, and HPV genotypes were determined by hybridization of PCR products with type-specific biotinylated probes.

RESULTS

Of the 127 participants, 55 tested positive and 72 tested negative for HPV DNA. While there was no difference between the two groups with regards to age or to number of pregnancies, higher numbers of smokers and of women with multiple sexual partners and abnormal cytology were seen in the HPV-positive group (P < 0.001). HPV DNA was detected in the vaginal scrapes of all HPV-positive, but in none of the HPV-negative women (sensitivity and specificity = 1.0). Furthermore, the HPV genotype was the same in vaginal and endocervical specimens in all the HPV-positive women.

CONCLUSION

HPV detection by PCR, using endocervical or vaginal sampling, is a sensitive and highly specific test for the identification of HPV infection, in particular in women with cytomorphologically normal cervices.

The relationship of human papillomavirus (HPV) detection to pap smear classification of cervical-scraped cells in asymptomatic women in northeast Thailand

OBJECTIVE

To correlate the detection of human papillomavirus (HPV) with the Pap smear classification of cervical-scraped cells from asymptomatic women living in northeast Thailand.

METHODS

A total of 260 asymptomatic women attending the Obstetrics and Gynecology's Outpatient Clinic, Srinagarind Hospital, Thailand, were interviewed for risk factors and cervical scrapes were taken. The cells were examined by Pap smear for cytological changes and by PCR for HPV DNAs--nononcogenic (HPVs 6 and 11) and oncogenic (HPVs 16, 18 and 33) types. Cervical biopsies were taken from women with abnormal Pap smears for histological examination.

RESULTS

Of the 260 cervical smear samples, the cervical cells were classified as normal and abnormal in 174 and 86, respectively. Twenty-three percent of all samples were positive for overall HPV DNA. HPV DNAs (mostly HPVs 6 and 11) were detected in 21% of normal cells, and the higher detection rate (27%) for HPV DNA in abnormal cells gradually increased in severity from 16% in Class 3 to 35 and 60% in Classes 4 and 5, respectively. Histologically 46, 90 and 100% of HPV detection was associated with CIS, SCC and adenocarcinoma, respectively. Almost all of the HPV DNAs detected were types 16, 18 or 33. There was no significant association between HPV infection and reproduction history, sexual behavior and demographic variables.

CONCLUSION

We speculated that an abnormal Pap smear and the detection of an oncogenic type HPV may indicate the presence of neoplastic cells in asymptomatic woman who might be at risk for the development of cervical cancer.

DNA image cytometry and human papillomavirus (HPV) detection help to select smears at high risk of high-grade cervical lesions

Three samples were submitted from women undergoing routine screening (n=910): two smears (one for routine cytology and one for DNA image cytometry) and a scrape for human papillomavirus (HPV) testing. DNA histograms were classified as suspect in cases of aneuploidy, polyploidy, and/or diploidy with a high proliferation rate. Follow-up was available in 239 cases. The primary end-point was the presence of a high-grade squamous intraepithelial lesion (HGSIL) at biopsy. Seventy women (7.7%) had a high-risk (HR) HPV infection and a suspect DNA profile. In 77 women with cytological abnormalities, 28 HGSILs were detected: four with a prior diagnosis of ASCUS (all HR-HPV infected including three with a suspect DNA profile), three with smears evocative of LGSIL (all with HR-HPV infection and a suspect DNA profile), and 21 with smears evocative of HGSIL (all with HR-HPV infection and 20 with a suspect DNA profile). During the follow-up period, out of 239 women with a cytologically normal smear at first entry, five developed a HGSIL; all were HR-HPV-positive and four had a suspect DNA profile at the first smear. HR-HPV detection alone gives a sensitivity of 100% for the detection of HGSIL, with a specificity of 84.3%, whereas DNA measurement associated with HPV testing significantly enhances the specificity to 95.4%. Thus, the combination of HPV testing and DNA measurement provides a highly sensitive and specific evaluation of the risk of HGSIL on cervical smears.

Clinical studies of human papilloma vaccines in pre-invasive and invasive cancer

Cervical cancer is the second most common cause of cancer death in women worldwide. It is almost invariably associated with infection with human papilloma virus (HPV) particularly types 16 and 18. The ubiquitous expression of E6 and E7 oncogene products has been recognised as an attractive target for CTL-mediated immunotherapy. In-vivo expansion of an HPV oncogene product specific MHC class 1 restricted response has been demonstrated using intradermally administered live vaccinia virus HPV 16 and 18 E6/E7 gene construct (TA-HPV, Cantab Pharmaceuticals). Responses have been seen in 1/3 evaluable patients with advanced cervical cancer, and 3/12 CIN3 volunteers, and in 4/29 patients with early invasive cervical cancer (Rankin et al. Proceedings of 91st AACR Meeting, San Francisco, April 2000). In addition, the adoptive transfer of ex vivo HPV 16 or 18 positive autologous tumour lysate pulsed dendritic cells is currently being tested as an alternative means of expanding HPV specific CTL in advanced cervical cancer patients. So far an HLA-A*O201 restricted CD8 T cell response has been recorded in the single HLA-A*O201 patient whose tumour was shown to be HPV16 positive. It appears therefore feasible to induce HPV specific CTL responses in patients with cervical cancer using several vaccine strategies. However, further clinical trials are needed to determine the full anti-tumour potential of this vaccine based immunotherapy.

Validity of vaginal testing in detecting human papillomavirus (HPV) genotypes

The aim of this study was to assess the validity and usefulness of vaginal scrapes in detecting cervical human papillomavirus (HPV) DNA by the polymerase chain reaction (PCR). The study group comprised 23 women tested positive and 28 women tested negative for cervical HPV DNA by PCR, and confirmed by histopathology. At the time of specimen collection, both vaginal and endocervical scrapes were taken from these women, and tested for HPV DNA by PCR, using MY09/MY11 primer system. HPV genotypes were analyzed by hybridizing PCR products with HPV type-specific biotinylated probes. HPV DNA was detected in both vaginal and cervical scrapes from the HPV-positive, but not from HPV-negative group. In the HPV-positive group, the same HPV type was found in vaginal and endocervical scrapes, giving a positive predictive value of 1.0. The results indicate that HPV types can be detected in vaginal scrapes, and recommend utilization of the less invasive vaginal testing for the routine detection of HPV DNA.

Identification and functional analysis of sequence rearrangements in the long control region of human papillomavirus type 16 Af-1 variants isolated from Ugandan penile carcinomas

Human papillomavirus type 16 (HPV-16) is the predominant HPV isolate found in malignancies of male and female lower genital tracts. However, only a small percentage of individuals infected with high-risk HPVs develop a genital neoplasia, suggesting that additional events at both the cellular and the virus level are necessary for the progression to cancer, including genetic mutations/rearrangements of viral sequences involved in the oncogenic process. In this study, the genetic stability of the long control region (LCR) (nt 7289-114), which regulates expression levels of oncoproteins E6 and E7, was analysed in HPV-16 isolates from penile carcinoma (PC) biopsies of patients recruited from Uganda, one of the countries with the highest incidence of genital cancers in both men and women. Nucleotide changes within the LCR region typical of the African-1 (Af-1) lineage were observed in all HPV-16 isolates. Two out of five samples showed further rearrangements of the enhancer region. The functional activity of LCR with Af-1 mutations and/or rearrangements was evaluated by cloning each LCR into CAT expression vectors, followed by transfection in several epithelial and non-epithelial cell lines. CAT expression levels driven by a rearranged LCR were significantly higher than those driven by Af-1 or European prototype LCRs. Furthermore, in the NIH3T3 focus formation assay, the transforming activity of E6 and E7 genes, driven by a mutated or rearranged LCR, was 1.4- to 3.0-fold higher, respectively. These results indicate that rearrangements within the LCR of HPV-16 isolated from African PCs are frequently found (2 out of 5, 40%). It is also shown that increased HPV LCR activity is associated with an increased E6/E7-mediated in vitro transforming activity, suggesting that natural variants can play a major role in the pathogenesis of genital carcinomas.

Human papillomavirus detection by the hybrid capture II assay: a reliable test to select women with normal cervical smears at risk for developing cervical lesions

The reliability of the Hybrid Capture II (HC-II; Digene, Silver Spring, MD, U.S.A.) assay was tested in detecting 18 human Papillomavirus (HPV) types for the screening of cervical lesions. Cytology, HPV testing, colposcopy, and biopsy were used to monitor 204 women with normal smears at the first entry. The median follow-up was 15 months (range, 4-27 months). The primary endpoint was clinical progression defined as the presence of a cervical intraepithelial lesion at the biopsy. In the patient population of 204 HPV-infected women, 81 (39.7%) had a persistent HPV infection at two or three examinations with a final histologic diagnosis of 14 high-grade and 13 low-grade squamous intraepithelial lesions (SIL) within 4 to 22 months. Women with regressive HPV infection did not develop any lesion during the same period. The evaluation of the viral load of high-risk HPV by the HC-II did not represent a sensitive approach to predict the persistence or the apparition of high-grade lesions. Thus, persistent high-risk HPV infection detected with HC-II represents a reliable tool to select populations at risk for the development of high-grade cervical lesions.

Generation of tumor-specific cytotoxic T lymphocytes by stimulation with HPV type 16 E7 peptide-pulsed dendritic cells: an approach to immunotherapy of cervical cancer

OBJECTIVE

The aim of this study was to generate HPV-16 E7 peptide-specific cytotoxic T lymphocytes (CTLs) in vitro for future adoptive immunotherapy of cervical cancer.

METHODS

Peripheral blood mononuclear cells (PBMC) were isolated from HLA-A2+ healthy donors. The PBMCs were incubated with HPV-16 E7(11-20) peptide and varying cytokines in the primary culture. Restimulation was performed weekly with peptide-pulsed, irradiated autologous PBMCs. Alternatively, the PBMCs were depleted of abundant CD4+ cells and stimulated with HPV-16 E7(11-20) peptide-pulsed dendritic cells. Cytolytic activity was determined by a standard 4-h (51)Cr-release assay.

RESULTS

After 6 weeks in culture, we were able to establish peptide-specific CTL lines in one of seven donors by incubating PBMCs with HPV-16 E7(11-20) peptide. When we employed autologous peptide-pulsed dendritic cells to stimulate CD8+ cell-enriched PBMCs, we obtained CTL lines in four of seven donors. The primed CTLs were able to lyse the HLA-A2+ and HPV-16+ cervical cancer cell line Caski. SiHa, an HLA-A2-, but HPV 16+, cervical cancer cell line could be lysed only after transfection with HLA-A2. In addition, a high cytotoxicity (>80%) was obtained against peptide-pulsed, but not unpulsed, targets such as autologous Ebstein-Barr virus-immortalized B cells or allogeneic lipopolysaccaride-stimulated PBMCs. DCs were clearly the most potent of all tested antigen presenting cells to stimulate a CTL response in a proliferation assay.

CONCLUSION

HPV-16 E7 peptide-specific CTLs could be generated in vitro. A practical protocol to expand the CTLs to a sufficient number for an application in a clinical trial is in progress.

Human papillomavirus genotype spectrum in Czech women: correlation of HPV DNA presence with antibodies against HPV-16, 18, and 33 virus-like particles

Because the biological spectrum of human papillomavirus (HPV) genotypes present in cervical cancer lesions varies according to the geographical region studied, and because little genotype information is available for Central and Eastern European countries, we studied the endemic HPV-genotype spectrum in cervical samples collected from women visiting gynaecological departments of selected hospitals in the Czech Republic. In a series of 389 samples, 171 (44.0%) were positive for HPV DNA using a consensus-primer polymerase chain reaction (PCR). Genotyping of the HPV PCR products was done using dot-blot hybridisation with type-specific oligonucleotide probes and thermocycle DNA sequencing. Twenty-two different HPV types were detected, HPV-16 being the most prevalent type irrespective of severity of the lesions (55.0%). Multiple HPV types were found in 16.4% of our HPV-DNA-positive samples. The prevalence of HPV infection was 23.0% in women with normal findings and 59.4% in patients with cervical neoplasia, and increased significantly with the severity of the disease: 52.9% in low-grade lesions, 58.0% in high-grade lesions, and 73.5% in cervical carcinomas (P for trend < .00001). In the sera of 191 subjects, 89 with normal findings and 102 with different forms of cervical neoplasia, the prevalence of HPV-specific IgG antibodies was tested by an enzyme-linked immunosorbent assay (ELISA) using virus-like particles (VLPs) of HPV-16, -18, and -33. Antibodies were significantly more prevalent in HPV-DNA-positive than in HPV-DNA-negative women and there was no association with age. In agreement with the results of HPV genotyping, antibodies reactive with HPV-16 VLPs were the most frequent and, moreover, their prevalence increased with the cervical lesion severity. About half of the subjects with smears in which either HPV-16 or HPV-33 DNA had been detected possessed antibodies reactive with homotypic VLPs. With HPV-18-DNA-positive subjects, however, fewer than 25% displayed homotypic antibodies. In general, subjects older than 30 years of age had antibodies reactive to HPV-specific VLPs more often than subjects younger than 30 years of age. In women with benign findings, the seropositivity to HPV-16, -18, and -33 VLPs increased with age, whereas in women with cervical neoplasia the seropositivity decreased with age.

Hybrid Capture II-based human papillomavirus detection, a sensitive test to detect in routine high-grade cervical lesions: a preliminary study on 1518 women

Hybrid Capture II (HC-II) is a commercial human papillomavirus (HPV) detection test designed to detect 18 HPV types divided into high-risk and low-risk groups. We have tested 1647 scrapes from 1518 unselected women attending routine cytological screening by this assay for the detection of histologically proven high-grade lesions. The reliability of this test was also evaluated on 117 fresh cone biopsy samples. HPV DNA has been detected in 400 scrapes (24.3%), 296 containing a high-risk HPV (18.0%). All the smears evocative of high-grade lesions were positive for high-risk HPV, and high-risk HPV were detected in all the 34 cases presenting a histologically proven high-grade lesion and in 68 (97.1%) of the 70 cone biopsy samples showing a high-grade lesion or an invasive carcinoma. Thus, the sensitivity was superior to the sensitivity of cytology (85.3%). Nevertheless, the quantitative approach provided by the HC-II assay for the assessment of the viral load could not clearly distinguish among cases with or without high-grade lesions. Thus this assay is recommended for the screening of high-grade lesions on a large scale, in association with classic cytology.

Epidemiology and biology of cervical cancer

Worldwide, cancer of the cervix is the second leading cause of cancer death in women: each year, an estimated 500,000 cases are newly diagnosed. Among populations, there are large differences in incidence rates of invasive cervical cancer: these reflect the influence of environmental factors, screening Papanicolaou (Pap) tests, and treatment of pre-invasive lesions. The high-risk human papillomavirus (HPV) subtypes 16, 18, 31, 33, and 51 have been recovered from more than 95% of cervical cancers. We have made great strides in understanding the molecular mechanism of oncogenesis of this virus, focusing on the action of the E6 and E7 viral oncoproteins. These oncoproteins function by inactivating cell cycle regulators p53 and retinoblastoma (Rb), thus providing the initial event in progression to malignancy. Cervical cancers develop from precursor lesions, which are termed squamous intraepithelial lesions (SIL) and are graded as high or low, depending on the degree of disruption of epithelial differentiation. Viral production occurs in low-grade lesions and is restricted to basal cells. In carcinomas, viral DNA is found integrated into the host genome, but no viral production is seen. The well-defined pre-invasive stages, as well as the viral factors involved at the molecular level, make cervical carcinoma a good model for investigating immune therapeutic alternatives or adjuvants to standard treatments.

Use of the same archival papanicolanou smears for detection of human papillomavirus by cytology and polymerase chain reaction

An optimal method for the processing of archival cervical Papanicolaou (pap)-stained smears for the amplification of human papillomavirus (HPV) DNA by polymerase chain reaction (PCR) was developed. This methodology was then applied to a series of 44 pap smears designated as HPV positive or negative (on the basis of both major and minor cytological criteria) or cervical intraepithelial neoplasia (CIN)-cancer. For the detection of HPV DNA, each sample was tested with the consensus GP5/6 primers, and when negative, with CPI-IIG primers. The HPV DNA was detected in 100% (8 of 8) of CIN-cancer smears using the GP5/6 primers. In smears with cytological evidence of HPV without CIN. the use of both sets of primers yielded positive results in 100% (19 of 19) of the samples. Direct sequence analysis of PCR products showed that 16 of the 27 HPV-positive samples contained more recently described HPV types. When tested with both primer combinations, all 17 cytologically negative smears were positive for beta-globin but negative for HPV DNA. The findings show the value of using archival pap smears for further investigations to address issues such as latency, but they indicate that cytological criteria and DNA technology will be critical factors in the reliability of the results.

Detection and quantitation of human papillomavirus by using the fluorescent 5' exonuclease assay

A method for the detection and quantitation of oncogenic human papillomavirus (HPV) was developed by using the fluorescent 5' exonuclease assay. The method is based on the amplification of a 180-bp fragment from the 3' part of the E1 open reading frame in a single PCR with type-specific probes for HPV types 16, 18, 31, 33, and 35. The probes can be used separately or in combinations of up to three probes per assay. Quantitation over a range of 10(1) to 10(6) initial HPV copies was possible by using real-time detection of the accumulation of fluorescence with cycle number. Reconstitution experiments, performed to mimic mixed infections, showed that individual HPV types can be detected down to a ratio of about 1% in a mixture. The performance of the assay depends on DNA quality, the presence of PCR inhibitors, and the number of different probes used simultaneously. This homogeneous assay provides a fast and sensitive way of screening for oncogenic HPV types in biopsy specimens as well as cervical smear samples. The closed-tube nature of the assay and the inclusion of uracil N'-glycosylase reduces cross contamination of PCR products to a minimum. A similar assay for beta-actin was used in parallel for quantitation of genomic DNA. After normalizing the samples for genomic DNA content, the mean number of HPV copies per cell could be calculated.

Human papillomavirus cervical infection and associated risk factors in a region of Argentina with a high incidence of cervical carcinoma

OBJECTIVE

To assess the prevalence and potential risk factors associated with human papillomavirus (HPV) cervical infection among women residing in a region of northeastern Argentina with a high incidence of cervical cancer.

METHODS

A case-control study of 330 women participating in a cervical cytological screening program conducted in Posadas city, Misiones, Argentina, from February 1997 to November 1998 was carried out. Standardized questionnaires were administered, and clinical examination including colposcopy was performed. Fresh endocervical specimens for HPV DNA detection by generic polymerase chain reaction were collected and the products typed by dot-blot hybridization.

RESULTS

Human papillomavirus DNA was found in 61% of samples analyzed (185/301). Samples with normal cytology had a 43% infection rate (85/199), while those classified as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, and invasive cervical carcinoma had an infection rate of 96% (53/55), 100% (29/29), and 100% (18/18), respectively. Human papillomavirus typing showed a 64% (118/185) prevalence of type 16 among all the infected population analyzed; type 16 was detected among 49% (42/85) of infected samples with normal cytology and in an average of 74% (74/100) with abnormal cytology. Sexual behavior, residence in southern Paraguay, and history of a previous sexually transmitted diseases were the main risk factors associated with high-grade cervical lesions.

CONCLUSIONS

An elevated prevalence of HPV infection was detected in this population, which also has a high incidence of cervical cancer. The broad distribution of high-risk HPV type 16 in women with normal cytology and colposcopy suggests that viral infection is an important determinant of regional cancer incidence.

Distribution of 14 high risk HPV types in cervical intraepithelial neoplasia detected by a non-radioactive general primer PCR mediated enzyme immunoassay

AIM

To evaluate the presence of high risk human papillomaviruses (HPV) in cervical smears showing intraepithelial neoplasia (CIN).

METHODS

The presence of 14 high risk HPV was evaluated in 114 cervical smears with CIN of different degrees, by comparing a non-radioactive polymerase chain reaction (PCR) enzyme immunoassay (EIA) with conventional PCR followed by radioactive Southern blot hybridisation. General primer PCR amplicons detecting low risk and high risk HPV were typed for 14 different high risk HPV types (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) by a non-radioactive PCR-EIA. Virus load of HPV 16 positive CIN was assessed using the semiquantitative PCR-EIA.

RESULTS

Histological evaluation confirmed CIN I in 49 cases (mean age 29.0 years, range 17 to 52), CIN II in 31 cases (mean age 30.8 years, 18 to 54), and CIN III in 34 cases (mean age 31.1 years, 16 to 57). The non-radioactive PCR-EIA showed an overall agreement rate of 90% (kappa value 0.75) when compared with conventional general primer PCR followed by radioactive Southern blot hybridisation. High risk HPVs were detected in 47% of CIN I, 77% of CIN II, and 97% of CIN III (p < or = 0.02). HPV types 39, 51, 56, and 58 were found in CIN I exclusively (between 2% and 8%). HPV 16 and HPV 31 were detected in 12% and 2% of CIN I, 35% and 21% of CIN II, and 74% and 13% of CIN III, respectively (p < or = 0.03 and p < or = 0.04). The virus load estimated by the semiquantitative PCR-EIA of HPV 16 was similar in CIN I, CIN II, and CIN III.

CONCLUSIONS

The PCR-EIA has high clinical sensitivity for detecting CIN II/III (90%). There was a significantly higher prevalence rate of HPV 16 and 31 in CIN III than in CIN I and II.

Detection and identification of human papilloma viral DNA, types 16, 18, and 33, by a combination of polymerase chain reaction and a colorimetric solid phase capture hybridisation assay

A colorimetric microplate hybridization assay was developed previously to simplify detection procedures of DNA fragments resulting from polymerase chain reactions (PCR). This format has now been adapted for the simultaneous detection and identification of three human papillomavirus (HPV), types 16, 18 and 33, associated frequently with cervical cancer. This post-PCR detection system uses three type-specific capture oligonucleotides linked covalently to a single microplate well and three type-specific multibiotinylated oligonucleotidic probes for detection. It therefore offers a double specificity; the first is conferred by pairs of primers, specific of each type of virus tested, and the second, by the sets of capture and detection probes which are complementary to internal regions of the amplified DNA fragments. The detection format outperformed agarose gel electrophoresis of amplified DNA products in sensitivity and specificity. The rapidity and simplicity of this hybridisation system would justify its use in routine diagnostic examination of cervical specimens (smears and biopsies).

Hybrid capture II, a new sensitive test for human papillomavirus detection. Comparison with hybrid capture I and PCR results in cervical lesions

AIM

To test a new assay for the detection of human papillomavirus (HPV) DNA, hybrid capture II (HC II), compared with the previous commercialized hybrid capture I (HC I) and polymerase chain reaction (PCR) results on cervical scrapes from fresh cone excision biopsy samples.

METHODS

The three methods were used on cervical scrapes from 42 fresh cone excision biopsy samples. There were nine metaplastic and inflammatory lesions, five low grade lesions, and 28 high grade lesions. PCR was performed using the general primers GP5+/GP6+. The viral load of high risk HPV DNA was estimated by the ratio of relative light units to positive control values in the samples.

RESULTS

The sensitivity of HC I for the detection of high grade lesions was 71.4%, while it was 92.8% for HC II and 96.4% for the PCR. Considering only the absence of detectable cervical in situ neoplasia, the specificity was 88.9% for HC I, 66.7% for HC II, and 66.7% for PCR. With HC II, for a ratio of cervical sample to normal control of > 200, the sensitivity for the detection of high grade lesion was only 34.6% with a specificity of 66.7%.

CONCLUSIONS

HPV detection with the HC II assay is more sensitive than the previous HC I and represents a more convenient and easier test than PCR for routine use. Nevertheless the viral load estimated with this test cannot be a reliable predictive indicator of high grade lesions.

Cervical screening adjuncts: recent advances

In an effort to reduce the false-negative rate of cervical cytologic findings, several new technologies have recently evolved. Automated cytologic testing (PapNet, AutoPap 300 QC) proposes to rescreen negative conventional cytologic findings to identify smears likely to be false negative. Fluid-based monolayers (ThinPrep, CytoRich) propose to reduce the false-negative rates by optimizing the collection and preparation of cells. Human papillomavirus deoxyribonucleic acid testing by Hybrid Capture has been proposed for a variety of screening and triage roles. Visual screening after application of acetic acid is done by cervicography by use of a photographic technique, whereas in speculoscopy the screening is done by direct visualization of the cervix by the primary care provider. Polarprobe uses biophysical parameters and a computer algorithm to give an instantaneous prediction of the likelihood of cervical disease. Each of these techniques, as well as the clinical experience with them, is reviewed. Current and possible future uses are discussed with regard to both clinical usefulness and cost-effectiveness.

Comparative analysis of human papillomavirus detection by hybrid capture assay and routine cytologic screening to detect high-grade cervical lesions

A commercial HPV detection test, Hybrid Capture (HC), designed to detect 14 HPV types divided into high-risk and low-risk groups, has been evaluated. A total of 1064 scrapes from 1028 unselected women attending routine cytologic screening were tested and results were compared with those of classic cytologic screening and cervical biopsies. The reliability of the test was also evaluated on 38 fresh conization samples. HPV DNA was detected in 108 women (10.5%), including 90 infected by a high-risk HPV (8.8%); 25 high-grade lesions were detected histologically, and high-risk HPV was found in 16 of these 25 women (64%), and in 27 (71%) of the 38 conization samples. The overall sensitivity of HC in detecting high-grade SIL on cervical scrapes and conization samples was 71.2%, while its positive predictive value was 17.8%. Classic cytologic screening appeared to be the most sensitive method (84%) for detecting high-grade SIL, with a positive predictive value of 91.3%. The lower sensitivity of HC limits its use for screening high-grade lesions on a large scale, even though it may be useful for reducing cytologically false-negative results. Moreover, the quantitative approach provided by the HC assay for assessment of the viral load cannot clearly distinguish among cases with or without high-grade lesions.

DNA-EIA to detect high and low risk HPV genotypes in cervical lesions with E6/E7 primer mediated multiplex PCR

BACKGROUND

Oncogenicity of human papillomavirus (HPV) DNA in premalignant and malignant uterine cervical diseases is mainly induced by E6/E7 open reading frame (ORF). The presence of an oncogenic HPV DNA may be a diagnostic marker for the detection of cytologically negative smears.

AIMS

To evaluate an original polymerase chain reaction enzyme immunoassay (PCR-EIA) for the detection and typing of oncogenic and non-oncogenic HPV types.

METHODS

The test was an original multiplex labelled PCR-EIA for the detection and typing of oncogenic and non-oncogenic HPV using three consensus sequence primers within the oncogenic E6/E7 ORF. One primer was dinitrophenyl (DNP) labelled and the DNP labelled amplimers could be further hybridised with specific biotinylated oligoprobes mixed in only two cocktails: oncogenic (16, 18, 31, 33, 35, 52, and 58) and non-oncogenic (6 and 11) HPV types in only two wells; then biotinylated oligoprobes were deposited in streptavidin-coated microplates. The PCR-EIA was validated on HPV plasmids (types 6, 11, 16, 18, 31, 35, 52, and 58) and used to evaluate cervical scrapes from 181 patients (median age 32 years) at high risk for cervical cancer.

RESULTS

HPV were detected in the cervical scrapes of 88 of 181 patients (48.6%); nine with non-oncogenic HPV (5.0%) and 79 with oncogenic HPV (43.6%) including 29 coinfections with oncogenic and non-oncogenic HPV. The number of oncogenic HPV infections increased with the presence of high grade lesions: 95.8% of the cervical scrapes from patients with high grade lesions contained oncogenic HPV compared with 32.1% of the specimens from patients without any lesions detectable by colposcopy and/or by cytological examination of the cervical smears. Moreover, 60% of cervical scrapes exhibiting low grade lesions contained oncogenic HPV.

CONCLUSIONS

This test is simple, specific, sensitive, safe, fast, reproducible, and easy to use in routine practice. Thus, it is possible to detect simultaneously on a simple cervical scrape, two kinds of HPV--oncogenic and non-oncogenic--in just two microplate wells with non-isotopic oligoprobes.

Prevalence of six types of human papillomavirus in inverted papilloma and papillary transitional cell carcinoma of the bladder: an evaluation by polymerase chain reaction

AIMS

To study the prevalence of high risk oncogenic human papillomaviruses (HPV) in inverted papilloma and papillary transitional cell carcinoma of the bladder.

METHODS

Ten cases of inverted papilloma and 20 cases of papillary transitional cell carcinoma of the bladder from Chinese patients in Hong Kong were examined for the presence of HPV type 6, 11, 16, 18, 31, and 33 genomes using the polymerase chain reaction and HPV type specific primer probe combinations on paraffin wax embedded biopsy specimens.

RESULTS

Of the 10 cases of inverted papilloma, cases 1 and 6 showed the presence of HPV types 16 and 18, respectively. Six of the 20 papillary transitional cell carcinomas were positive for HPV type 18. The other HPV types were not detected.

CONCLUSIONS

HPV type 18 was found in 60% and 30% of cases of inverted papilloma and papillary transitional cell carcinoma of the bladder, respectively. These tumours were rarely associated with HPV types 6, 11, 16, 31, and 33. The role of HPV type 18 in oncogenesis of inverted papilloma and transitional cell carcinoma of the bladder requires further studies.

Human papillomavirus findings in relation to cervical intraepithelial neoplasia grade: a study on 476 Stockholm women, using PCR for detection and typing of HPV

Among human papillomavirus (HPV) types found in humans, there is a strong association between HPV 16, 18, 31, and 33, and cervical cancer. The relationship between various grades of dysplasia and HPV type is less clear. To elucidate this point, the authors tested 476 cytological and histological samples from cervix with polymerase chain reaction (PCR) for HPV using consensus primer My 09-11 and type-specific primers. All cases were divided into groups on the basis of cytology: "normal cases" (ie, women with other disease than cervical intraepithelial neoplasia [CIN]), and CIN I, II, and III. Out of the "normal cases," in which women with a previous history of condyloma and dysplasia were included, 69% had HPV with type 6 as the most common one. Of all CIN I cases, 71% were HPV positive, and HPV type 6 and 16 were equally common. In CIN II cases, HPV 16 was the most common type, whereas HPV 6 accounted for only 7.5% of cases in this group as single virus type. HPV 16 was also the most common type in the CIN III group, followed by type 33. Double and even multiple infections occurred in all groups.

Different detectability of high-risk HPV in smears from incident and prevalent high-grade squamous intraepithelial lesions of the cervix

Human papillomavirus (HPV) status in cervical smears from cervical intraepithelial neoplasia (CIN) 2/3 diagnosed in 36 of 892 women with a history of normal cytology and colposcopy (incident CIN 2/3) was compared with CIN 2/3 in 40 patients with a history of abnormal cytology (prevalent CIN 2/3). In all patients cervical smears for HPV testing and cytology and two cervigrams were taken. The scrapes were collected in hybrid capture assay solution and analyzed with the hybrid capture and general primer/type-specific primer polymerase chain reaction system (GP/TS-PCR) after DNA extraction. Patients with incident and prevalent CIN 2/3 were similar with respect to age. By GP/TS-PCR carried out under suboptimal conditions due to DNA extraction, HPV DNA was detected in 69.4% (25 of 36) of smears from incident CIN 2/3 compared to 95% (38 of 40) in prevalent CIN 2/3 (P = 0.003). Using hybrid capture, smears of incident CIN 2/3 were HPV positive in 50% (18 of 36) compared to 80% (32 of 40) in prevalent CIN 2/3 (P = 0.006). High-risk HPVs were significantly less common in smears from incident CIN 2/3 compared with prevalent CIN 2/3: 36.1% vs 72.5% by GP/TS-PCR (P = 0.001) and 47.2% vs 80% by hybrid capture assay (P = 0.003), respectively. Virus load in HPV-positive smears of prevalent CIN 2/3 was significantly higher than of incident CIN 2/3 using semiquantitative PCR (P = 0.0005). Thus, high-risk HPV types were detected less frequently and in lower concentration in smears from incident CIN 2/3 than in smears from prevalent CIN 2/3.

Modulation of antigen processing and presentation by persistent virus infections and in tumors

Cell-mediated immunity is effective against cells harboring active virus replication and is critical for the elimination of ongoing infections, opposing tumor progression, and reducing or preventing the reactivation of persistent viruses and tumor metastasis. The capacity of persistent viruses and tumor cells to maintain a long-term relationship with their host presupposes mechanisms for circumventing antiviral or antitumor defenses. By suppressing the expression of molecules associated with antigen processing and presentation, abrogation of the major immune mechanism that deals with the elimination of infected and transformed cells is achieved. This is accomplished in tumors predominantly by transcriptional downregulation of genes encoding class I major histocompatibility complex antigens, peptide transporter molecules, and the proteasome-associated low molecular mass protease subunits, and in cells expressing viral proteins by interfering with peptide transport and the assembly/transport of class I complexes. In addition, virus-infected cells and selected tumor cells express mainly nonimmunogenic or antagonistic peptide epitopes. This review describes mechanisms used by viruses and in transformed cells for interference with antigen processing and presentation and addresses their significance for in vivo viral persistence and tumor progression.

Human papillomavirus infection and invasive cervical neoplasia: a study of prevalence and morphology

The prevalence of human papillomavirus (HPV) DNA sequences in 45 cervical cancer biopsies was examined with the hot-start polymerase chain reaction (PCR), employing HPV consensus primers from the L1 region. The cases comprised 38 squamous cell carcinomas, three adenosquamous carcinomas, and four adenocarcinomas. PCR products were typed with single-strand conformation polymorphism (SSCP) and the HPV types detected were correlated with tumour type. Forty-three biopsies were HPV-positive, HPV16 being the most prevalent type. HPV18/33/45/58 were also detected, but no low-risk or multiple types. Keratinizing squamous cell carcinoma was invariably associated with HPV16 and adenosquamous carcinoma and adenocarcinoma with HPVs 18/45. Non-keratinizing squamous cell carcinomas harboured all five detected types. Our data corroborate the view that malignant cervical tumours are almost invariably associated with high-risk HPV and that certain malignant cervical tumour phenotypes correlate with specific HPV types.

Do HPV-negative cervical carcinomas exist?

Based on improvements in HPV detection technology, it appears that an almost 100% HPV association is reached for cervical cancer, as demonstrated in an accompanying paper in this issue of the Journal. Factors which may explain the rare cases in which no HPV DNA is detectable include: improper sampling; disruption of HPV by integration events; the existence of still unidentified HPVs; sensitivity of the method; and the mechanism of transformation. Finally, epidemiological studies identifying HPV independent risk factors are necessary to answer the question of whether HPV independent pathways exist for cervical carcinogenesis.

Present evidence on the value of HPV testing for cervical cancer screening: a model-based exploration of the (cost-)effectiveness

Human papillomavirus (HPV) is the main risk factor for invasive cervical cancer. High risk ratios are found in cross-sectional data on HPV prevalence. The question raised is whether this present evidence is sufficient for making firm recommendations on HPV screening. A validated cervical cancer screening model was extended by adding HPV infection as a possible precursor of cervical intraepithelial neoplasia (CIN). Two widely different model quantifications were constructed so that both were compatible with the observed HPV risk ratios. One model assumed a much longer duration of HPV infection before progressing to CIN and a higher sensitivity of the HPV test than the other. In one version of the model, the calculated mortality reduction from HPV screening was higher and the (cost-)effectiveness was much better than for Pap smear screening. In the other version, outcomes were the opposite, although the cost-effectiveness of the combined HPV + cytology test was close to that of Pap smear screening. Although small follow-up studies and studies with limited strength of design suggest that HPV testing may well improve cervical cancer screening, only large longitudinal screening studies on the association between HPV infection and the development of neoplasias can give outcomes that would enable a firm conclusion to be made on the (cost-)effectiveness of HPV screening. Prospective studies should address women aged 30-60 years.

Correlation between polymerase chain reaction and cervical cytology for detection of human papillomavirus infection in women with and without dysplasia

The aim of this study was to compare the ability of two methods, the polymerase chain reaction (PCR) and cervical cytology, to detect HPV infection. The study population included 222 randomly selected women without dysplasia (controls) and 91 women with histologically confirmed dysplasia (CIN II-III) (cases). In women without dysplasia, 8.6% had cytological signs of HPV infection, whereas 15.3% were HPV DNA positive by PCR. In women with dysplasia, 72.5% had cytological signs of HPV infection, whereas 90.1% were HPV PCR positive. The statistical agreement between the two diagnostic methods was low (controls: kappa = 0.26, cases: kappa = -0.03). In total, PCR failed to detect 17 of 85 women with cytological signs of HPV infection, whereas cervical cytology failed to detect 48 of 116 HPV PCR-positive women. In women with dysplasia, but not in women without dysplasia, the oncogenic HPV types were associated with cytological signs of HPV infection.

The current status of therapeutic HPV vaccine

Cervical carcinoma is the second most common cause of cancer-related deaths in women worldwide. Recurrences occur in 15% of the patients after optimal treatment of low-risk early-stage disease. Treatment results of recurrent disease are relatively poor and for this reason new therapeutic strategies are warranted. Viral infection with human papillomavirus seems to have an essential part in the aetiology of cervical carcinoma. Evidence for the assumption that cervical carcinoma, among other malignancies such as melanomas, renal malignancies and Kaposi sarcoma, are immunogenic is provided by the fact that these malignancies grow more rapidly in the presence of systemic immunosuppression. Spontaneous regression for these tumour types is also described and immunohistochemical studies show extensive infiltrates in the tumour, consisting of immunocompetent cells. It is thus postulated that cellular immunity, and mainly the T-cell system plays an important role in the antitumour defence in cervical carcinoma. This review describes the rationale for the use of immunotherapy as treatment for cervical carcinoma as well as the results of recent developments in tumour immunology and its implications for the clinical use of immunotherapeutical approaches.

Clinical role of HPV testing

The subjectivity of morphologic methods contributes to a "swamping" of colposcopic services, excessive costs, overdiagnosis, and overtreatment. HPV DNA testing provides the objectivity required to clarify difficult patient management issues, including follow-up, for low-grade cytologic abnormalities (ASCUS and LSIL), noncorrelating (nonconfirmed) Pap smears, evaluation of nondiagnostic lower genital tract lesions, and cytology and histology laboratory quality assurance. Additionally, favorable preliminary data on HPV testing as a primary screen raise the exciting prospect of potentially lowering costs of cervical cancer-screening programs, while further decreasing the incidence of cervical cancer.

Human papilloma virus has no prognostic significance in cervical carcinoma

The prognostic significance of the detection of HPV (human papilloma virus) DNA in cervical carcinoma was evaluated in 223 cases treated from January 1988 to November 1989. HPV DNA was detected by PCR (polymerase chain reaction) on fresh tumour specimens obtained before therapy was started. HPV DNA of any type was detected in 93.3% of all tumours, HPV16 was the predominant type and was detected in 69% of cases. HPV18 was more frequent in adeno- and adenosquamous carcinoma than in squamous cell carcinoma and occurred more often in poorly differentiated tumours than in more highly differentiated tumours. Patients with HPV negative tumours were on average older than patients with tumours containing HPV. Neither presence of HPV DNA nor HPV type had prognostic significance. In 63 women with early stage tumours submitted to surgery, no difference was found in the frequency of lymph node metastasis, vessel invasion or prognosis related to HPV type. We conclude that neither the presence nor the type of HPV DNA had any prognostic significance in cervical carcinoma.

Virologic screening

Detection of high risk human papillomaviruses (HPV) has a high potential value for secondary prevention of cervical cancer. HPV testing can augment the sensitivity of conventional cytologic screening and can be used for triaging patients with a history of mild cytological abnormalities or low grade cervical intraepithelial neoplasia (CIN). Before screening for high risk HPVs can be generally recommended, refined commercially available HPV tests have to be established and their value has to shown in large epidemiologic studies.