Screening Of Cervical Lesions Research Articles

Genotyping of Human Papillomaviruses by a Novel One-Step Typing Method with Multiplex PCR and Clinical Applications

We describe here a rapid, high-throughput genotyping procedure that allows the simultaneous detection of 16 high- and low-risk genital human papillomavirus (HPV) types by multiplex PCR in a single reaction tube. Multiplex PCR is based on the amplification of HPV DNA by sets of HPV genotype-specific primers, and the genotypes of HPV are visually identified by the sizes of amplicons after they are separated by capillary electrophoresis. The procedure does not include a hybridization step with HPV-specific probes and is rapid and labor-saving. We detected all 16 HPV genotypes (types 16, 58, 52, 51, 56, 31, 18, 39, 66, 59, 6, 33, 30, 35, 45, and 11) with a high sensitivity and a high degree of reproducibility. By using this newly developed method, we conducted a pilot study to examine the correlation between the prevalence and genotype distributions of HPV and the cytological group classifications for 547 cervical samples. Compared with the group of samples considered normal (14.7%), there was a significant increase in the prevalence of HPV in women with atypical squamous cells of unknown significance (61.3%), low-grade intraepithelial lesions (75.8%), and high-grade intraepithelial lesions (HSILs) (82.2%). The prevalence and distribution of type 58 were correlated with cytological malignancies, with the highest prevalence in women with HSILs. In conclusion, the novel multiplex PCR method described appears to be highly suitable not only for the screening of cervical cancer precursor lesions but also for the characterization of genotype distributions in large-scale epidemiological studies and HPV vaccination trials.

HPV and Cervical Cancer: Updates on an Established Relationship

Despite cervical cancer being considered a preventable disease, it still remains the second most common malignancy in women worldwide, with a higher incidence in underdeveloped countries. Human papillomavirus (HPV) is considered the causative agent of cervical cancer. The major mechanisms through which HPV contributes to neoplastic initiation and progression include the activity of 2 viral oncoproteins, E6 and E7, which interfere with critical cell cycle tumor suppressive proteins, p53 and retinoblastoma (Rb) protein. However, HPV infection alone is not sufficient to induce malignant transformation, and other significant cofactors contribute to the multi-step process of tumor formation, such as individual genetic variations as well as environmental factors. However, these cofactors are not important in the absence of HPV. Papanicolaou testing (Pap smear) and HPV DNA testing are tools used in the screening and diagnosis of cervical neoplastic lesions. Vaccination against HPV appears to be cost-effective in the prevention of HPV infection. A thorough understanding of the mechanisms that underline HPV carcinogenesis may result in the development of sophisticated targeted therapeutic approaches, such as antisense oligonucleotides against HPV oncoproteins.

Human papillomavirus (HPV) vaccines

In the last 15 years, fifteen of the human papillomaviruses (HPVs) that infect the genital tract have been recognized as the etiological agents of cervical cancer. Cervical cancer is thus a cancer that could be prevented by immuniza- tion. The recently licensed HPV subunit vaccine and the availability of another prophylactic vaccine in the near future for types 16 and 18 make this a realizable goal. The safety, immunogenicity and efficacy demonstrated for two vaccines are very promising. Phase I and phase II clinical trials have determined the tolerance, immunogenicity, dose and schedule of injections and phase IIb and phase III clinical trials have demonstrated the high efficacy of these vaccines. More than 80 % protection against incident infections was observed and close to 100 % protection was observed against persistent infections associated with cervical lesions. Anti-HPV antibodies persisted for 4-5 years, with antibody titers 5 to 17 times higher than observed in control subjects with anti-HPV antibodies ac- quired after natural infection. However, there are still some unresolved questions such as duration of protection, need for booster dose, protective level of anti-HPV antibodies, and whether there is protection against infection with HPV types closely related to HPV-16 and HPV-18 but not incorporated in the vac- cines. For a maximum efficacy, papillomavirus vaccines must be administered to pre-adolescents and adolescents before the beginning of sexual activity. Vaccine coverage and hence the overall efficacy of vaccination against HPV will depend on public health policies, social attitudes and cost of the vaccines. HPV immu- nization should significantly reduce the incidence of cervical cancers in 10 to 30 years, and should reduce the number of treatments due to a significant reduction in precancerous lesions in the shorter term. These vaccines also have the potential to reduce the incidence of other cancers such as anal, vulval, vaginal, and penial cancers for which the HPV prevalence is lower or the association with HPV infection is weaker. HPV vaccination and screening of precancerous cervical lesions are complementary measures and the implementation of HPV vaccination is an opportunity to strengthen the health policies for prevention of cervical cancer.

The evaluation of human papillomavirus DNA testing in primary screening for cervical lesions in a large Japanese population

To examine the utility of human papillomavirus (HPV) DNA testing for the screening of cervical cancer and its precursors, a prospective cohort study was performed in which a total of 8156 women with a median age of 36 years were enrolled. Two smear samples scraped from the uterine cervix were served for Papanicolaou test and HPV DNA testing (Hybrid Capture-II system). HPV-positive samples were further examined for HPV subtype using a DNA microarray chip. Women with cytologic abnormality or those with high-risk HPV DNA were further examined by colposcopy to determine histologic diagnosis. High-risk HPV DNA was detected in 11% of the general population, with higher prevalence of specific types, including 52, 16, 58, 51, 56, and 18. As expected, younger women were likely to have increased frequency of HPV infection. Notably, HPV DNA testing detected all 45 cases of cervical intraepithelial neoplasia (CIN) 3, while cytologic findings were negative in 6 of these cases. It is of particular interest that CIN was commonly associated with multiple HPV types, while invasive cancers had a single type of HPV. In terms of both sensitivity and positive predictive value in detecting the CIN, HPV DNA testing is superior to cytology. However, most importantly, HPV DNA testing in combination with cytology significantly improved the efficacy to CIN screening.

The evaluation of human papillomavirus DNA testing in primary screening for cervical lesions in a large Japanese population

To examine the utility of human papillomavirus (HPV) DNA testing for the screening of cervical cancer and its precursors, a prospective cohort study was performed in which a total of 8156 women with a median age of 36 years were enrolled. Two smear samples scraped from the uterine cervix were served for Papanicolaou test and HPV DNA testing (Hybrid Capture-II system). HPV-positive samples were further examined for HPV subtype using a DNA microarry chip. Women with cytologic abnormality or those with high-risk HPV DNA were further examined by colposcopy to determine histologic diagnosis. High-risk HPV DNA was detected in 11% of the general population, with higher prevalence of specific types, including 52, 16, 58, 51, 56, and 18. As expected, younger women were likely to have increased frequency of HPV infection. Notably, HPV DNA testing detected all 45 cases of cervical intraepithelial neoplasia (CIN) 3, while cytologic findings were negative in 6 of these cases. It is of particular interest that CIN was commonly associated with multiple HPV types, while invasive cancers had a single type of HPV. In terms of both sensitivity and positive predictive value in detecting the CIN, HPV DNA testing is superior to cytology. However, most importantly, HPV DNA testing in combination with cytology significantly improved the efficacy to CIN screening.

Screening for cancer: future potential

Much progress has been made in cancer screening over the past decade, but a great deal more needs to be done if screening is to make a major impact on worldwide cancer mortality. Where fully implemented, cytological screening for cervical precursor lesions has had a major impact on mortality. However, the cost and required infrastructure levels are high, and new approaches are needed if screening is to be effective in the developing world. Testing for the human papillomavirus and automated liquid based cytology offer great promise to improve quality, reduce overall cost and make screening more viable generally. Breast screening has been less successful, although useful mortality benefits have been achieved in women aged over 50 years. Full implementation in countries that can afford it will save lives, but radical new approaches will be needed to conquer breast cancer. Colorectal cancer screening offers the best hope of a major reduction in cancer mortality over the next decade. Less certainty exists about screening for other major cancers such as lung, prostate and ovary, but a range of potential approaches merit investigation.

967 PUBLICATION HPV DNA detection and the shedding of viral infected cells in the blood of women with cervical cancer

Human papillomaviruses (HPVs) constitute a large and highly heterogeneous group of over 100 genotypes distributed in 25 species and five genera of the family Papillomaviridae. Their small, nonenveloped, icosahedral capsid contains a double-stranded, covalently closed, circular DNA molecule of 7500–8000 bp. The viral genome is divided into a noncoding regulatory region, an early (E) region encoding nonstructural proteins, and a late (L) region encoding the two capsid proteins. HPVs are host specific and infect specifically cutaneous or mucosal squamous epithelia. Virus replication is tightly coupled to the terminal differentiation of keratinocytes. HPVs cause widespread, often asymptomatic and transient infections. They induce benign epithelial proliferations (warts, papillomas, and low-grade intraepithelial lesions) that usually regress. Invasive anogenital and cutaneous carcinomas may develop from persistent lesions caused by specific (high-risk) HPV types. Over 95% of carcinomas of the uterine cervix, the second most common cancer in women worldwide, are etiologically related to specific, sexually transmitted HPV types. HPV-16 and HPV-18 account for 70% of them. DNA tests for the detection of high-risk HPV types represent a means to improve the sensitivity of the cytological screening of precancerous cervical lesions. Prophylactic vaccines based on virus-like particles of HPV-16 and HPV-18 are now available.

965 PUBLICATION Beneficial effect of chemotherapy on CD8+ T cell responses in advanced ovarian cancer

Human papillomaviruses (HPVs) constitute a large and highly heterogeneous group of over 100 genotypes distributed in 25 species and five genera of the family Papillomaviridae. Their small, nonenveloped, icosahedral capsid contains a double-stranded, covalently closed, circular DNA molecule of 7500–8000 bp. The viral genome is divided into a noncoding regulatory region, an early (E) region encoding nonstructural proteins, and a late (L) region encoding the two capsid proteins. HPVs are host specific and infect specifically cutaneous or mucosal squamous epithelia. Virus replication is tightly coupled to the terminal differentiation of keratinocytes. HPVs cause widespread, often asymptomatic and transient infections. They induce benign epithelial proliferations (warts, papillomas, and low-grade intraepithelial lesions) that usually regress. Invasive anogenital and cutaneous carcinomas may develop from persistent lesions caused by specific (high-risk) HPV types. Over 95% of carcinomas of the uterine cervix, the second most common cancer in women worldwide, are etiologically related to specific, sexually transmitted HPV types. HPV-16 and HPV-18 account for 70% of them. DNA tests for the detection of high-risk HPV types represent a means to improve the sensitivity of the cytological screening of precancerous cervical lesions. Prophylactic vaccines based on virus-like particles of HPV-16 and HPV-18 are now available.

A comparison of four screening methods for cervical neoplasia

Objective: To evaluate the sensitivity and accuracy of 4 screening methods for cervical neoplasia. Methods: Cervical samples from 450 women were evaluated for human papillomavirus DNA with a second-generation hybridization assay. Visual inspection, colposcopy, and liquid-based cytology were also performed for 273 of these women. The sensitivity, specificity, efficiency, positive predictive value (PPV), negative predictive value (NPV), Youden index, and κ value of the different screening methods were compared. Results: Liquid-based cytology was superior in specificity (98.63%) and PPV (92.86%) to visual inspection and colposcopy, while human papillomavirus DNA testing was superior in sensitivity (88.89%) and NPV (97.10%) to visual inspection and colposcopy. The best concordance with histologic findings was achieved by using both liquid-based cytology and viral DNA hybridization. Conclusion: Visual inspection and colposcopy should not be used when screening for early stage cervical lesions. The DNA hybridization assay is the best choice in primary screening, if available. Screening should begin at the age of 20 years.

A five-year review of female genital tract malignancies in Sokoto, Northwestern Nigeria

Although female genital malignancies are known to contribute significantly to the disease burden in the developing world, little has been reported on them from the northwest of Nigeria. This study was thus conducted to determine the prevalence and clinico-pathological patterns of these tumors in Sokoto, Nigeria. A retrospective review of cancers of the female genital tract diagnosed at Usmanu Danfodiyo University Teaching Hospital, Sokoto in the period 1999 to 2003 was carried out. Female genital cancers were found to constitute about 14% of all cancers in the center. The pateints\' ages ranged from 11 months to 95 years with a mean of 44 (SDI5) years. The majority of tumors were of cervical origin (61.5%) followed by ovarian cancers (18.2%) and malignant gestational trophoblastic tumors (13.3%). We conclude that female genital malignancies are an important public health problem in northwestern Nigeria and that access to appropriate, cost-effective prevention and treatment options is required for a large number of women. It is recommended that this process is accelerated through heightened awareness of the female genital cancers among members of the community and health care providers. In addition, innovative approaches to screening and treatment of precancerous cervical lesions and improved service delivery systems are required. Keywords: female genital malignancies, Sokoto, Nigeria Mary Slessor Journal of Medicine Vol. 5(1), 2005: 51-56

Human papillomavirus testing in cervical cancer screening

Human papillomavirus testing in cervical cancer screening

Detection of Cervical Cancer and High Grade Neoplastic Lesions by a Combination of Liquid‐Based Sampling Preparation and DNA Measurements Using Automated Image Cytometry

Objective: To establish if measurements of DNA ploidy could be used to assist cytopathologists and cytotechnologists in population based cervical cancer screening programs in countries where manually reading the slides is impossible due to the lack of sufficient skilled cytotechnologists. The goal of such program is to identify only clinically significant lesions, i.e. those where a clinical intervention to remove the lesion is required immediately. Study Design: A total of 9905 women were enrolled in the study. Cervical samples were taken with a cervix brush that was then placed into a fixative solution. The cells were separated from mucus by mechanical and chemical treatment and then deposited onto microscope slides by a cytocentrifuge. Two slides were prepared from each case; one slide was stained by Papanicolaou stain for manual cytology examination, while the other slide was stained by a DNA specific stain. The latter slide was used to determine the relative amount of DNA in the cell nuclei. Results: A total of 876 women were followed by colposcopy examination where biopsies were taken from the visible lesions or from suspicious areas and histopathology diagnosed 459 as normal or benign cases, 325 as CIN1, 36 as CIN2, 25 as CIN3/CIS, and 31 as invasive cancer. Of these 876 cases, manual cytology called 655 normal or ASCUS, 197 as LSIL, 16 cases as HSIL, and 8 as cancer. DNA measurements found 704 cases having no cells with DNA greater than 5c, 98 cases where there were 1 or 2 cells having DNA amount greater than 5c, and 74 cases where there were 3 or more cells having DNA amount greater than 5c. If manual cytology were to be used to refer all cases of HSIL and cancer to colposcopy and biopsy, 23 lesions that had to be removed would have been discovered (2 CIN2, 11 CIN3/CIS, and 10 cancers), for a sensitivity of 25.0±5.2% at specificity of 99.9±0.1%. If DNA assisted cytology were to be used instead, and all cases having 3 or more cells with DNA amount greater than 5c were to be referred to colposcopy and biopsy, then 50 lesions that had to be removed would have been discovered (10 CIN2, 15 CIN3/CIS and 25 cancers) for the sensitivity of 54.3±6.2% at specificity of 96.9±0.6%. Conclusions: The study suggests that screening for high grade cervical neoplastic lesions and cervical cancer by DNA assisted cytology could be implemented with minimal use of skilled cytotechnologists, at least in those countries where it would be difficult to introduce population based screening for cervical cancer due to the lack of availability of such skilled cytotechnologists.

In this issue

In this issue

2001 Consensus Guidelines for the Management of Women with Cervical Cytological Abnormalities

EACH YEAR APPROXIMATELY 50 million women undergo Papanicolaou testing in the United States. Of these, approximately 3.5 million (7%) are diagnosed with a cytological abnormality requiring additional follow-up or evaluation. Determining which women with cytological abnormalities are at risk for significant cervical disease, performing appropriate diagnostic workups, and treating cancer precursors present a major public health challenge. There are a number of reasons why comprehensive, evidence-based guidelines are needed for the management of women with cervical cytological abnormalities. One reason is that a National Cancer Institute workshop recently revised the criteria used by cytologists to render certain cytological interpretations, as well as the terminology used for reporting cervical cytology results (ie, the Bethesda System). Other reasons include a better understanding of the pathogenesis and natural history of human papillomavirus (HPV) and cervical cancer precursors, and the availability of data from the National Cancer Institute’s randomized Atypical Squamous Cells of Undetermined Significance/Low-grade Squamous Intraepithelial Lesion (ASCUS/LSIL) Triage Study (ALTS) (D. Solomon, MD, written communication, September 6-8, 2001). Moreover, existing guidelines were developed before sensitive molecular methods for detecting high-risk types of HPV and liquid-based cytology methods became widely available. Data are now available suggesting that these new technologies, when used together, are attractive alternatives to older approaches for managing women with cer-

Screening cervical lesions with Fourier transform infrared spectroscopy

The screening results were reported based on the Fourier transform infrared spectroscopy (FTIR) analysis of the samples of exfoliated cervical cells from 354 women. Their spectra can be sorted into two types based on the emerging or not of the absorption bands near 970 cm−1 and 1 170 cm−1: T1 (83.1%) type without emerging, and T2 (16.9%) type with obviously emerging. All of the samples assigned to T1 were cytologically diagnosed as normal or within normal limits (Pap I). 28.9% and 71.1% of samples exhibiting T2 profile, were cytologically evaluated as Pap I and abnormal respectively. 3 women in the abnormal group were diagnosed as to have cervical cells with changes associated with high grade of inflammation, cervical scar and cervical erosion. Furthermore, based on the progressive change of the relative intensities of the absorption bands, both T1 and T2 profiles can be categorized into 6 subtypes. The observed heterogeneous spectra and the progressive changes in the absorption frequencies and the relative intensities exhibit features suggestive of the progressive process of cervical lesion. The FTIR method has the potential to complement the cytological smear for large-volume screening of cervical lesions.

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.

International trends in incidence of cervical cancer: II. Squamous-cell carcinoma.

Time trends in the incidence of squamous-cell carcinomas of the cervix during the period 1973-1991 were examined using data provided by 60 population-based cancer registries from 32 defined populations in 25 countries. Three components of the incidence trend were studied: age, calendar period of diagnosis and birth cohort. Cumulative incidence rates per 1,000 person-years for 2 groups, age ranges 25-49 and 50-74 years, were calculated from the model that best described the incidence data. A significant decline in incidence was noted in the American populations (except for US Hispanic), Australia, the non-Maori women of New Zealand, northern and western Europe (except Italy and Spain, where the rates remain stable) and Asian populations (except Malay women of Singapore, who have stable rates). These trends were of similar magnitude for the whole age range studied (25-74 years). An increasing trend, mainly restricted to younger women, was found for Slovakia, Jewish women born in Israel and the United Kingdom. In Slovenia, the increasing trend was observed for all age groups. The predominant pattern shown by cancer registries in developed countries is of a reduction in the incidence of squamous cervical cancer. This could be, at least partially, attributed to the widespread practice of screening for cervical lesions. The major exception to the pattern is observed in the United Kingdom, though the increasing incidence in young women has changed to a decrease in recent years. There are only a few series covering a long period of time in developing countries, but there is little evidence for a major impact of screening.

Interêt de la détection des papillomavirus humains par hybridation en phase liquide en routine: comparaison avec l'examen cytologique classique pour le dépistage des lésions pré-cancéreuses et cancéreuses du col utérin

Human papillomavirus (HPV) infection, especially by oncogenic types is the major cause of human cervical precancerous and cancerous lesions. HPV detection in routine has given rise to numerous contradictory studies using various and different techniques and is still debated. The aim of the present work is to test the reliability of HPV detection for the screening of cervical lesions, in a series of 2385 unselected women attending cervical screening and in 165 fresh cone biopsy samples. For that, a simple, easy to perform liquid hybridization assay in microtiters, Hybrid Capture (HC II, Digene®) has been used to detect 18 HPV types (5 non oncogenic and 13 oncogenic). In our experience, the general sensitivity of HC II to detect high grade lesions is close to 100 %, with a specificity of 84.7 %, a positive predictive value of 15.3 % and a negative predictive value of 100 %. Classic cytologic examination gives a sensitivity of 87.5 % and a specificity of 93.8%. Thus the HC II assay could be used in routine in association with cytology to improve significantly the screening of cervical lesions.

Screening for cancer: future potential

Much progress has been made in cancer screening over the past decade, but a great deal more needs to be done if screening is to make a major impact on worldwide cancer mortality. Where fully implemented, cytological screening for cervical precursor lesions has had a major impact on mortality. However, the cost and required infrastructure levels are high, and new approaches are needed if screening is to be effective in the developing world. Testing for the human papillomavirus and automated liquid based cytology offer great promise to improve quality, reduce overall cost and make screening more viable generally. Breast screening has been less successful, although useful mortality benefits have been achieved in women aged over 50 years. Full implementation in countries that can afford it will save lives, but radical new approaches will be needed to conquer breast cancer. Colorectal cancer screening offers the best hope of a major reduction in cancer mortality over the next decade. Less certainty exists about screening for other major cancers such as lung, prostate and ovary, but a range of potential approaches merit investigation. ©

Improving the screening of cervical precancerous lesions by improving laboratory quality assurance in cytology.

It is well recognized that despite repeated screening, a certain number of women continue to develop invasive cervical cancer. This fact emphasizes the importance of identifying the potential failures of the detection system and of analyzing the reasons for such failures. The quality of cytological diagnoses, particularly the high number of false-negative smears, frequently is debated. Sampling errors include cell collection (bad sampling and paucicellularity), smear preparation, and the presence of blood and inflammation. The need to improve slide quality has encouraged the development of a number of devices aimed at automating slide making. Screening errors also can result in incorrect diagnoses and have led to quality assurance guidelines that are unique to cytology but are not universally accepted. In recent years, several commercially sponsored systems have been developed that use partial automation of the reading process to improve manual quality control. Laboratory quality assurance is necessary. The various options described in this article, if applied, should improve the quality of cervical cytology.