Is human papillomavirus testing of value in clinical practice?

Comparison of three management strategies for patients with atypical squamous cells of undetermined significance, after six months delay: a three-year experience in an Iranian university hospital

BACKGROUND

A Pap test result of atypical squamous cells of undetermined significance (ASCUS) presents a clinical challenge. Only 5-10% of women with ASCUS harbour serious cervical disease.

METHODS

We screened 3619 women, who attended to Mirza Koochak Khan Hospital at Tehran University of Medical Sciences with Pap smears, of whom 100 returned with ASCUS. After six months, each subject underwent a standard cytology (conventional Pap smear), human papillomavirus (HPV) DNA testing (identifying high-risk HPV types with polymerase chain reaction) and colposcopy with multiple cervical biopsies.

RESULTS

Mean age was 44.09 +/- 8.6 years. The estimated prevalence of cervical intraepithelial neoplasia (CIN) II or higher was 4%. When histologically verified high-grade lesions (> or = CIN II) were observed, the relative sensitivity of HPV DNA testing was 100% compared with conventional Pap smear, which performed 75% versus 100% relative sensitivity, respectively, using cytological diagnosis high-grade squamous intraepithelial lesion, or low-grade squamous intraepithelial lesion (LSIL) as the cut-off. Negative and positive predictive values (NPV and PPV) of Pap test were 98.9% and 100%. The NPV and PPV of HPV DNA testing were 100%.

CONCLUSIONS

Although less complicated than colposcopy, the repeat Pap smear triage algorithm for ASCUS may underdiagnose some women with high-grade CIN, when compared with colposcopy. Considering the high sensitivity of HPV testing, it may be useful as an alternative to the current policy of six-month repeat cytology for women with ASCUS results.

Development of a sensitive and specific assay combining multiplex PCR and DNA microarray primer extension to detect high-risk mucosal human papillomavirus types

The importance of assays for the detection and typing of human papillomaviruses (HPVs) in clinical and epidemiological studies has been well demonstrated. Several accurate methods for HPV detection and typing have been developed. However, comparative studies showed that several assays have different sensitivities for the detection of specific HPV types, particularly in the case of multiple infections. Here, we describe a novel one-shot method for the detection and typing of 19 mucosal high-risk (HR) HPV types (types 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 70, 73, and 82). This assay combines two different techniques: multiplex PCR with HPV type-specific primers for amplification of viral DNA and array primer extension (APEX) for typing. This novel method has been validated with artificial mixtures of HPV DNAs and clinical samples that were already analyzed for the presence of mucosal HPV types by a different consensus PCR method, i.e., GP5+/GP6+. Our data showed a very good agreement between the results from the multiplex PCR/APEX assay and those from the GP5+/GP6+ PCR (overall rates of HPV positivity, 63.0 and 60.9%, respectively). Whereas the GP5+/GP6+ PCR was slightly more sensitive for the detection of HPV type 16 (HPV-16), multiplex PCR-APEX found a higher number of infections with HPV-33, HPV-53, and multiple HPV types. These favorable features and the high-throughput potential make our present novel assay ideal for large-scale clinical and epidemiological studies aimed at determining the spectrum of mucosal HR HPV types in cervical specimens.

Role of human papillomavirus DNA testing in management of women with atypical squamous cells of undetermined significance

To find the sensitivity, specificity, and positive and negative predictive values of the high-risk group human papillomavirus (HPV) DNA testing as a triage tool to detect high-grade squamous intraepithelial lesions (HSILs, ie, cervical intraepithelial neoplasia [CIN] 2 or worse) in women with a cytologic smear showing atypical squamous cells of undetermined significance (ASC-US). All new cases with cytologic smears showing ASC-US that presented in King Chulalongkorn Memorial Hospital from January 2003 to November 2003, excluding known cases of HSILs and pregnancies, were enrolled. Cervical cell samplings were done by cervical cytobrush technique and tested for high-risk group HPV with the Hybrid Capture 2 (HC2) test. All participants were examined under a colposcope. Then cervicographs were taken before colposcopic-directed cervical biopsies were done. Of the 90 ASC-US cases enrolled, the pathologic results were normal in 30.0%, squamous metaplasia in 16.7%, CIN 1 in 37.8%, CIN 2 in 1.1%, CIN 3 in 11.1%, and microinvasive cervical carcinoma in 3.3%. The prevalence of HSILs and the prevalence of high-risk HPV detection were 15.6% and 38.9%, respectively. Using pathologic results from cervical biopsy as the gold standard, the HC2 has the sensitivity, specificity, and positive and negative predictive values of 85.7%, 69.7%, 34.3%, and 96.4%, respectively, to detect HSILs. High-risk group HPV detection can be used as an additional triage test to detect HSILs in women having ASC-US with high sensitivity and negative predictive value.

A study of abnormal cervical cytology in pregnant women

During the 4 year routine study of smears in 2,919 pregnant women, 33 cases of abnormals of the uterine cervix were detected (1.13%). The patients were followed with uterine cervical cytology and colposcopy and in case of need, sometimes punch biopsies were performed. The results of the cytologies, 33 cases with abnormalities were detected. There were 26 cases classified as class IIIa, 7 cases were class IIIb. All the cases underwent colposcopy. For the 17 cases that showed lesions by colposcopy, and punch biopsies were performed. The results of histologic examination were wide variety, five chronic cervicitis, one condyloma, one mild dysplasia, three moderate dysplasia, three severe dysplasia, three carcinoma in situ, and one microinvasive carcinoma. Only two cases were treated during pregnancy; one with condyloma underwent Laser vaporization and another with microinvasive carcinoma underwent LEEP conization. Other cases were given conservative treatment during pregnancy. Excluding one case for persistence smear class IIIa of histology condyloma, all the cases showed regression of dysplasia and carcinoma in situ with treatment after delivery. We conclude that lesions up to carcinoma in situ do not require intervention during pregnancy but microinvasive carcinoma is suspected, diagnostic LEEP conization is necessary, even during pregnancy.

A study of abnormal cervical cytology in pregnant women

During the 4-year routing study of smears in 2,919 pregnant women, 33 cases of abnormalities of the uterine cervix were detected (1.13%). The patients were followed with uterine cervical cytology and colposcopy, and in case of need, sometimes punch biopsies were performed. As a result of the cytologies, 33 cases with abnormalities were detected. There were 26 cases classified as class IIIa and 7 cases were class IIIb. All cases underwent colposcopy. For the 17 cases that showed lesions by colposcopy, punch biopsies were performed. The results of histologic examination were wide: 5 chronic cervicitis, 1 condyloma, 1 mild dysplasia, 3 moderate dysplasia, 3 severe dysplasia, 3 carcinoma in situ, and 1 microinvasive carcinoma. Only two cases were treated during pregnancy, condyloma underwent Laser vaporization and microinvasive carcinoma underwent Loop electrosurgical excision procedure (LEEP) conization. Other cases were conservative treatment during pregnancy. Excluding one case for persistence smear class IIIa of histology condyloma, all the other cases with regression of dysplasia and carcinoma in situ with treatment after delivery. We conclude that lesions up to carcinoma in situ do not require intervention during pregnancy but microinvasive carcinoma is suspected, diagnostic LEEP conization is necessary, even during pregnancy.

Multiplex nested PCR (MNP) assay for the detection of 15 high risk genotypes of human papillomavirus

BACKGROUND

Human papillomavirus (HPV) is now recognized as the causative agent in cervical cancer. The HPV genotypes that infect the genital region have been classified into high and low risk types according to their oncogenic potential. There is still uncertainty regarding rare HPV genotypes, however the types considered high risk in this study are: HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68 and 70.

OBJECTIVES

We have set out to develop a multiplex nested PCR (MNP) assay with primers directed at the early region of the HPV genome to detect 15 high risk HPV (HRHPV) genotypes. Since it is known that the late region of HPV is lost on integration into the host cell genome, the primers are directed at the early region of the HPV genome so as to ensure the detection of integrated virus, in the absence of the episomal form of the virus.

STUDY DESIGN

Primers were designed to detect specifically the high risk HPV in the MNP assay. The MNP assay was compared to a generic mucosal HPV nested PCR and another nested HRHPV PCR assay. DNA sequencing was carried out on the samples tested and matched with the PCR results.

RESULTS

The MNP assay demonstrated that it was able to detect all 15 HRHPV types and was positive for more CIN1, CIN2 and CIN3 cases than the other nested HRHPV PCR. Further to this, the PCR product sizes differ for most of the HRHPV types detected in this system, so it is possible to type most of these HRHPV by the molecular size of the PCR products.

CONCLUSION

The MNP assay detects 15 currently recognized HRHPV and could be very useful, in conjunction with the Pap smear, as a screening assay or to help manage Pap smears of uncertain cytology.

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.

Virologic Versus Cytologic Triage of Women With Equivocal Pap Smears: A Meta-analysis of the Accuracy To Detect High-Grade Intraepithelial Neoplasia

BACKGROUND

The appropriate management of women with minor cytologic lesions in their cervix is unclear. We performed a meta-analysis to assess the accuracy of human papillomavirus (HPV) DNA testing as an alternative to repeat cytology in women who had equivocal results on a previous Pap smear.

METHODS

Data were extracted from articles published between 1992 and 2002 that contained results of virologic and cytologic testing followed by colposcopically directed biopsy in women with an index smear showing atypical cells of undetermined significance (ASCUS). Fifteen studies were identified in which HPV triage and the histologic outcome (presence or absence of a cervical intraepithelial neoplasia of grade II or worse [CIN2+]) was documented. Nine, seven, and two studies also documented the accuracy of repeat cytology when the cutoff for abnormal cytology was set at a threshold of ASCUS or worse, low-grade squamous intraepithelial lesion (LSIL) or worse, or high-grade squamous intraepithelial lesion (HSIL) or worse, respectively. Random-effects models were used for pooling of accuracy parameters in case of interstudy heterogeneity. Differences in accuracy were assessed by pooling the ratio of the sensitivity (or specificity) of HPV testing to that of repeat cytology.

RESULTS

The sensitivity and specificity were 84.4% (95% confidence interval [CI] = 77.6% to 91.1%) and 72.9% (95% CI = 62.5% to 83.3%), respectively, for HPV testing overall and 94.8% (95% CI = 92.7% to 96.9%) and 67.3% (95% CI = 58.2% to 76.4%), respectively, for HPV testing in the eight studies that used the Hybrid Capture II assay. Sensitivity and specificity of repeat cytology at a threshold for abnormal cytology of ASCUS or worse was 81.8% (95% CI = 73.5% to 84.3%) and 57.6% (95% CI = 49.5% to 65.7%), respectively. Repeat cytology that used higher cytologic thresholds yielded substantially lower sensitivity but higher specificity than triage with the Hybrid Capture II assay. The ratio of the sensitivity of the Hybrid Capture II assay to that of repeat cytology at a threshold of ASCUS or worse pooled from the four studies that used both triage tests was 1.16 (95% CI = 1.04 to 1.29). The specificity ratio was not statistically different from unity.

CONCLUSION

The published literature indicates that the Hybrid Capture II assay has improved accuracy (higher sensitivity, similar specificity) than the repeat Pap smear using the threshold of ASCUS for an outcome of CIN2+ among women with equivocal cytologic results. The sensitivity of triage at higher cytologic cutoffs is poor.

Detection of viral infection and gene expression in clinical tissue specimens using branched DNA (bDNA) in situ hybridization

In situ hybridization (ISH) methods for detection of nucleic acid sequences have proved especially powerful for revealing genetic markers and gene expression in a morphological context. Although target and signal amplification technologies have enabled researchers to detect relatively low-abundance molecules in cell extracts, the sensitive detection of nucleic acid sequences in tissue specimens has proved more challenging. We recently reported the development of a branched DNA (bDNA) ISH method for detection of DNA and mRNA in whole cells. Based on bDNA signal amplification technology, bDNA ISH is highly sensitive and can detect one or two copies of DNA per cell. In this study we evaluated bDNA ISH for detection of nucleic acid sequences in tissue specimens. Using normal and human papillomavirus (HPV)-infected cervical biopsy specimens, we explored the cell type-specific distribution of HPV DNA and mRNA by bDNA ISH. We found that bDNA ISH allowed rapid, sensitive detection of nucleic acids with high specificity while preserving tissue morphology. As an adjunct to conventional histopathology, bDNA ISH may improve diagnostic accuracy and prognosis for viral and neoplastic diseases.

Role of the human papilloma virus in the development of cervical intraepithelial neoplasia and malignancy

Human papilloma virus (HPV) is a public health problem as a sexually transmitted disease and as a critical factor in the pathogenesis of various cancers. The clinical manifestations, epidemiology, and virology that are critical to understanding the process of cervical dysplasia and neoplasia are reviewed. A discussion of the cervical transformation zone and the classification of cervical dysplasia and neoplasia leads into the importance of the Papanicolaou smear in prevention of potentially devastating sequelae of this virus. The role of the immune system in the progression of the disease and how it relates to vaccines, as well as treatment and prevention of HPV, are reviewed.

Much higher risk of premalignant and malignant cervical diseases in younger women positive for HPV16 than in older women positive for HPV16

Human papillomavirus (HPV), particularly HPV16, is strongly associated with premalignant lesions of the uterine cervix and cervical cancer. However, HPV infection is a common sexually transmitted disease and only a few women develop cervical cancer. Although the presence of HPV and abnormal cytology are independent risk factors for cervical diseases, implementing both tests on every woman is argued not to be recommended mainly in terms of cost-effectiveness. During a 20-month period between October, 1994, and May, 1996, cervical swabs from 207 women who were referred for colposcopy because of cervical dyskaryosis (Papanicolaou class IIIa or higher) were examined by PCR for the presence of HPV16. When these women were divided into two groups; i.e., group A consisting of women who were 44 years old or younger (n = 111), and group B consisting of women who were 45 years old or older (n = 96), the risk of having premalignant and malignant cervical diseases upon infection with HPV16 was approximately 8 times higher in group A than in group B. Thus, we conclude that HPV-testing should be implemented on every young woman with an abnormal Papanicolaou smear test.

Colposcopic evaluation after a repeat atypical squamous cells of undetermined significance (ASCUS) smear

OBJECTIVES

Management of patients with atypical squamous cells of undetermined significance (ASCUS) remains controversial. We chose to repeat the Pap smear after four months. If ASCUS persisted in this second test, the patient was advised to undergo colposcopy. Our objective is to determine the clinical significance and the prediction of neoplasia among these patients through a colposcopic examination.

METHODS

Of 29,827 patients who had a Pap smear, ASCUS were detected in 1387 (5%) and persisted in the repeat smear of 225 (16%). Colposcopy and an additional Pap smear were performed on 186 patients.

RESULTS

Out of 186 colposcopic evaluations, 91 (49%) were normal and the patients had a negative Pap smear. Colposcopy was abnormal in 95/186 patients (51%) (Table 1). Histology of the directed biopsies revealed 38 (21%) low-grade squamous intraepithelial lesions (LSIL) and 17 (9%) high-grade squamous intraepithelial lesions (HSIL). Forty patients (21%) with normal biopsies had ASCUS for the third time in the Pap smear.

CONCLUSIONS

Colposcopic evaluation after a repeated Pap smear with ASCUS is an appropriate cost-effective management. Finding 30% of LSIL or HSIL justifies this additional investigation.

Is the human papillomavirus test in combination with the Papanicolaou test useful for management of patients with diagnoses of atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesions?

OBJECTIVE

To determine whether human papillomavirus (HPV) testing is useful in the evaluation of patients diagnosed with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL) and whether the HPV test is appropriate as an alternative screening method.

DESIGN

The results of Papanicolaou (Pap) tests and subsequent hybrid capture tube (HCT) II tests for high-risk-type HPV were analyzed for 457 patients. Among these tests, 208 histologic diagnoses were made and correlated with the results of Pap and HPV tests. The sensitivity and specificity of the Pap test, HPV test, and the combined method of Pap and HPV tests to detect cervical intraepithelial neoplasia (CIN) 2/3 and all CIN were also measured.

RESULTS

Sixty (63.8%) of 94 women with LSIL and 31 (26.3%) of 118 women with ASCUS tested positive for high-risk HPV. The sensitivity values for Pap tests in detecting all cases of CIN and CIN 2/3 were 91.4% and 92.9%, respectively. The sensitivity values of HCT II tests using the high-risk probe for detecting all cases of CIN and CIN 2/3 were 62.6% and 88.1%, respectively. Biopsies confirmed that 10 (22.7%) of 44 LSIL patients with high-risk HPV had CIN 2/3, but only 1 (4.5%) of 22 LSIL patients without high-risk HPV had CIN 2/3.

CONCLUSION

Testing for high-risk HPV with the HCT II test is useful in the detection of CIN 2/3 in LSIL groups and in the selection of patients for colposcopy in ASCUS groups, but it is not suitable for cervical cancer screening tests.

Expanded cytological referral criteria for colposcopy in cervical screening: comparison with human papillomavirus testing

OBJECTIVE

The goal of this study was to investigate whether expanded cytologic referral criteria for colposcopy or the addition of human papillomavirus (HPV) testing on cervical screening could improve the rates of detection of cervical intraepithelial neoplasia (CIN).

METHODS

HPV testing by semiquantitative polymerase chain reaction/ELISA was performed in 1000 women who were self-referred for routine Pap smear. They underwent colposcopy following an abnormal smear result or a positive HPV test. As abnormal smear results were considered reports of low- or high-grade squamous intraepithelial lesion, atypical squamous cells of undetermined significance, and even HPV-associated reactive cellular changes (mild koilocytosis, mild dyskeratocytosis, hyperchromatic nuclei, bimultinucleation, and cleared cytoplasm). Loop excision of the transformation zone was performed in women with cytology and colposcopy indicative of CIN, as well as in women with normal cytology but positive HPV test and colposcopic impression of CIN.

RESULTS

The Pap test was abnormal in 89% of the cases of CIN 1 (34/38) and 96% of CIN 2/3 (27/28) diagnosed in our population. HPV testing picked up four additional cases of CIN 1 (11%) and one case of CIN 2/3 (4%). Overall the HPV test detected 95% of the cases of CIN 1 (36/38) and 89% of the cases of CIN 2/3 (25/28).

CONCLUSION

HPV testing does not appear to add significantly to cytology in terms of positive predictive value or detection rate, if extended cytologic indications for colposcopy are used.

An update on human papillomavirus infection and Papanicolaou smears in adolescents

Human papillomavirus infection is one of the most common sexually transmitted infections in young women, and may lead to clinical sequelae such as anogenital condylomata and cervical squamous cell carcinoma. Recent data on the biology and natural history of HPV infection in adolescents will have important implications for the development of adolescent-specific protocols for cervical cancer screening and for follow-up of abnormal cytology.

Human papillomavirus testing in primary screening for the detection of high-grade cervical lesions: a study of 7932 women

High-risk human papillomaviruses (HR-HPV) are the necessary cause of cervical carcinomas. To determine whether HPR-HPV DNA detection in primary routine screening could represent a sensitive and reliable technique for the detection of high-grade squamous intraepithelial lesions (HGSIL), laboratory analysis using 2 cytologic techniques (conventional and liquid-based), HPV testing with Hybrid Capture II assay (HC-II), followed by colposcopic examination of women with abnormal cervical finding and/or persistent HR-HPV infection, was conducted in 7932 women who had routine cervical examination. The sensitivity of HPV testing for detecting a histologically proven HGSIL was 100%, higher than that of conventional (68.1%) and liquid-based (87.8%) cytology. The low specificities of 85.6% and 87.3% of HPV testing slightly increased to 88.4% and 90.1% if HPV testing was reserved for woman >30 years old. The quantitative approach provided by the HC-II assay for the assessment of the viral load was not reliable for predicting HGSIL in normal smears. HR-HPV testing could be proposed in primary screening in association with cytology. With conventional cytology it significantly improves the detection of HGSIL. With the use of the same cervical scrape for HPV testing and liquid-based cytology, HR-HPV testing would allow to select positive samples treated in a second time for cytology which gives a good specificity.

Relationships between 80 human papillomavirus genotypes and different grades of cervical intraepithelial neoplasia: association and causality

To clarify the causal relationship between human papillomavirus (HPV) and cervical intraepithelial neoplasia (CIN), we analyzed 386 unfixed biopsy specimens by blot hybridization at Tm -40 degrees C, targeting 38 skin and 42 genital HPVs. By the recognition of PstI, BanI, and MspI cleavage patterns, single genital, but no skin's HPVs were identified with more than 10 copies per cell in 354 CIN (88 CIN I, 94 CIN II, and 172 CIN III). HPVs 40, 42, 43, 54, 62, or 71 was found in 10 CIN I, while HPVs 18, 30, 39, 51, 56, 59, 66, 68, 69, or 82 was found in 35 CIN I, 20 CIN II, or 8 CIN III. On the other hand, HPVs 16, 31, 33, 35, 52, 58, or 67 was identified in 43 CIN I, 74 CIN II, or 164 CIN III. The results are strongly indicative that most genital HPVs have potency to induce CIN I; however, HPV 16 and its closely related types are able to efficiently induce CIN III. We discuss the definition of causal HPV for CIN with regard to viral prevalence and viral load.

Human papillomavirus (HPV) study of 691 pathological specimens from Quebec by PCR-direct sequencing approach

Human papillomaviruses (HPV) are etiological agents of cervical cancer. In order to address clinical demand for HPV detection and sequence typing, mostly in pre-cancerous cervical lesions, we applied our two-tier PCR-direct sequencing (PCR-DS) approach based on the use of both MY09/MY11 and GP5 + /GP6 + sets of primers. We tested 691 pathological specimens, all of which were biopsies, 75% of which were diagnosed histologically as cervical intraepithelial neoplasia (CIN) grades I-III. In total, 484 samples (70%) tested HPV-positive, yielding 531 HPV sequences from 47 HPV types, including two novel types. Four most frequently found HPV types accounted for 52.9% of all isolates: HPV6, 16, 11, and 31 (21.5%, 20.0%, 7.0%, and 4.5%, respectively). Some interesting results are the following: all currently known high-risk HPV (14 types) and low-risk HPV (6 types) were detected; HPV18 was not the 1st or 2nd but rather the 4th-5th most frequent high-risk HPV type; the highest detection rate for HPV (86%) among samples suspected to be HPV-infected was found in the youngest age group (0-10 years old), including 70% (44/63) "genital" HPV types; HPV types of undetermined cervical cancer risk represented 19% and of the total HPV isolates but were strongly increased in co-infections (36.5% of all isolates). To our knowledge, this is the largest sequencing-based study of HPV. The HPV types of unknown cancer risk, representing the majority of the known HPV types, 27 of the 47 types detected in this study, are not likely to play a major role in cervical cancer because their prevalence in CIN-I, II, and III declines from 16% to 8% to 2.5%. The two-tier PCR-DS method provides greater sensitivity than cycle sequencing using only one pair of primers. It could be used in a simple laboratory setting for quick and reliable typing of known and novel HPV from clinical specimens with fine sequence precision. It could also be applied to anti-cancer vaccine development.

Usefulness of human papilloma virus testing in the screening of cervical cancer precursor lesions: a retrospective study in 314 cases

OBJECTIVE

To assess the usefulness of human papilloma virus (HPV) typing for predicting pre-malignant and malignant cervical lesions.

STUDY DESIGN

314 women, who underwent colposcopy, biopsies and high and low-risk HPV typing after a confirmed abnormal routine Pap test were studied. HPV-DNAs were typed by using PCR technique.

RESULTS

We found a significant increasing rate of high-risk-HPV by the increasing severity of histology, ranging from 40% in negative cases to 86.9% in those with CIN3 lesions. The positive predictive value of high-risk-HPV ranged from 13.3% in patients with atypical squamous cells of undetermined significance (ASCUS) to 29.4% in those with HSIL. By contrast, negative predictive value was 96% in patients with ASCUS, 97.2% in low-grade squamous intraepithelial lesions (LSIL), and 71.4% in high-grade squamous intraepithelial lesions (HSIL). Sensitivity and specificity for detecting CIN2 or CIN3 was 86.0% and 41.3%, respectively.

CONCLUSIONS

The high negative predictive value of high-risk HPV testing suggests that HPV negativity could be used for predicting the absence of important cervical lesions, and therefore avoiding unnecessary colposcopy in ASCUS and LSIL cases.

[Human papillomavirus typing in routine cervical smears. Results from a series of 3778 patients]

AIM

As human papillomavirus (HPV) infection is a significant risk factor for cervical cancer, the aim of this study was to assess the efficacy of HPV detection techniques in predicting the presence or the development of a high-grade squamous intra epithelial lesion. Additional reasons for carrying out this investigation were as follows. It was considered that the clinical value of HPV typing may have been underestimated in certain previous reports, which based their findings on first-generation assays. Moreover, until the present investigation most studies only investigated the cases with abnormal smear findings and did not include long-term follow-up, nor detailed follow-up of women with a normal smear but positive HPV typing, although this patient subgroup is of particular interest. The patient population included 3778 women who underwent routine cytological cervical screening and who gave their informed consent to participate in this study, consisting of a cervical smear, HPV testing via a second-generation Hybrid Capture II assay (which is more sensitive than first-generation tests, and can detect 18 different HPV types, i.e., 13 oncogenic and five non-oncogenic types); and in the case of abnormal smear findings, colposcopic examination and directed biopsies of the sites of suspected lesions. The women with cytomorphologically normal cervical smears but which who HPV-positive were reexamined six months later.

RESULTS

HPV findings were positive in 66 cases where the initial smear indicated the presence of a high-grade lesion with the diagnosis confirmed by biopsy in 65 cases; in 155 cases (76.1%) where the initial smear indicated the presence of a low-grade lesion; in 44 (57.1%) out of 77 smears indicating the presence of ASCUS-type (atypical squamous cells of undetermined significance) lesions; and in 366 cases (10.5%) of apparently normal initial smears. After colposcopy and follow-up, a final diagnosis of high-grade lesion was made for 85 patients. All these patients were found to have high-risk (oncogene-positive) HPV at the first examination, but in only 65 cases (76.5%) was the initial smear indicative of a high-grade lesion. Finally, in the patient groups with low-grade or ASCUS-type smear findings or with an apparently normal smear, a high-grade lesion was only found in those patients with persistent high-risk HPV infection. In all, the sensitivity of the Hybrid Capture II assay in detecting high-grade lesions was 100% versus 85.9% for standard cytology. However, its specificity (86.3%) and positive predictive value were not as high as the latter.

CONCLUSION

The results of this study indicate that HPV typing via this second-generation assay displays good sensitivity for the detection of at-risk cases, i.e., those involving the presence or development of high-grade cervical lesions. However, a number of issues have to be addressed before HPV typing is adopted in clinical practice, such as the fairly high HPV prevalence in women aged over 60 years, and whether the implications of this are the same as for younger age groups. Also, the present cost of complete typing remains too high for it to be used on a widespread scale. Nevertheless, HPV typing may have a useful role to play in the detection of cervical cancer.

New technologies in cervical cancer precursor detection

The current literature reflects three routes toward improving cervical cancer screening. The first is to improve the test qualities of cytology-based screening. The use of liquid-based cytology and computerized analysis of Papanicolaou tests are examples of attempts at this approach. Secondly, through various combinations of parallel or sequential tests, either the sensitivity or the specificity of a given test could be improved depending on the tests chosen and the order in which they were performed (eg, Papanicolaou test followed by human papillomavirus [HPV] or vice versa). Several excellent studies have been published this year on the use of HPV DNA testing as a primary screening modality and as an adjunct to the triage of mildly abnormal cytologic findings. The recent literature also reflects increasing interest in visual inspection of the cervix and self-collected samples for HPV testing as an equally effective and viable alternative to cytology in low-resource settings. A third possibility is to make use of advances in digital and spectroscopic techniques. In these cost-conscious times, a significant number of articles address the cost-effectiveness of these technologies and the real value of cervical cancer screening. This article reviews the current literature concerning both the advent of new cervical cancer screening technologies and the rediscovery of old ones.

Recent advances in diagnosis and therapy of human papillomaviruses

Infection with human papillomavirus is extremely common throughout the world. Almost 50% of sexually active young women are infected with human papillomavirus and although most infections are transient, a subset has the potential to progress to invasive cancer. During the last 20 years, our understanding of the human papillomavirus life cycle and the role of human papillomavirus in human cancer has dramatically increased. Recent technological advances in human papillomavirus detection have provided the means to detect the presence of human papillomavirus with great sensitivity. In the context of patient care, there is still substantial debate regarding the optimal diagnostic and prognostic use of information derived from hybrid capture or polymerase chain reaction-based detection. The inventory of available treatment options is growing somewhat slowly. The most promising advances are being made in the clinical evaluation of candidates for prophylactic vaccination. This review is focused on the current status and future directions of prevention, diagnosis and therapy.

Testing for high-risk human papillomavirus types will become a standard of clinical care

Testing for high-risk human papillomavirus types should become a standard of care for women in the United States because cervical cancer is an infectious disease. Current care is based on cytologic screening and a pathologic staging of cellular tissue changes. Before these cellular modifications, there is a demonstrable pattern of human papillomavirus infection. Human papillomavirus is the most frequently acquired sexually transmitted disease in women and is usually eliminated without treatment. Persistence of high-risk human papillomavirus types can lead to abnormal cervical cellular changes. When these cervical cellular changes occur, physician interventions hasten human papillomavirus elimination. Currently, adding human papillomavirus screening to the Papanicolaou smear identifies a population for closer follow-up studies. In the future a vaccine should be introduced to prevent infections, and medical treatments to hasten the elimination of high-risk human papillomavirus types should become part of standard medical practice.

Role of routine human papillomavirus subtyping in cervical screening

Human papillomavirus testing has been evaluated as an adjunct to cervical cytologic screening. There is a well-established association between high-risk malignant subtypes of human papillomavirus infection and the development of neoplastic change. Although human papillomavirus infection is a necessary condition for malignant transformation, it is not a sufficient condition. Multiple cofactors are necessary for progression to dysplasia and then to invasive cervical cancer. Because of the multifactorial nature of malignant transformation, current methods of human papillomavirus testing do not add sufficient predictive and diagnostic information over that obtained by cytology and colposcopic biopsy to warrant routine clinical use.