New technologies in cervical cytology screening: a word of caution

Detection of Host Cell Gene/HPV DNA Methylation Markers: A Promising Triage Approach for Cervical Cancer

Cervical cancer is the most prevalent gynecologic malignancy, especially in women of low- and middle-income countries (LMICs). With a better understanding of the etiology and pathogenesis of cervical cancer, it has been well accepted that this type of cancer can be prevented and treated via early screening. Due to its higher sensitivity than cytology to identify precursor lesions of cervical cancer, detection of high-risk human papillomavirus (HR-HPV) DNA has been implemented as the primary screening approach. However, a high referral rate for colposcopy after HR-HPV DNA detection due to its low specificity in HR-HPV screening often leads to overtreatment and thus increases the healthcare burden. Emerging evidence has demonstrated that detection of host cell gene and/or HPV DNA methylation represents a promising approach for the early triage of cervical cancer in HR-HPV-positive women owing to its convenience and comparable performance to cytology, particularly in LMICs with limited healthcare resources. While numerous potential markers involving DNA methylation of host cell genes and the HPV genome have been identified thus far, it is crucial to define which genes or panels involving host and/or HPV are feasible and appropriate for large-scale screening and triage. An ideal approach for screening and triage of CIN/ICC requires high sensitivity and adequate specificity and is suitable for self-sampling and inexpensive to allow population-based screening, particularly in LMICs. In this review, we summarize the markers of host cell gene/HR-HPV DNA methylation and discuss their triage performance and feasibility for high-grade precancerous cervical intraepithelial neoplasia or worse (CIN2+ and CIN3+) in HR-HPV-positive women.

Safety and efficacy of the new CryoPop® cryotherapy device for cervical dysplasia in low- and middle-income countries: study protocol for a multicenter open-label non-inferiority clinical trial with historical controls

BACKGROUND

Cervical cancer is the fourth most common cancer in the world, affecting mainly women residing in low- and middle-income countries. Progression from a pre-invasive phase to that of an invasive phase generally takes years and provides a window of opportunity to screen for and treat precancerous lesions.

METHODS

This study is being conducted at four sites in north Karnataka, India. Community sensitization activities have been organized in the study areas to create awareness among stakeholders, including elected representatives, physicians, health care workers, and potential participants. Organized community based as well as hospital-based screening is being conducted using visual inspection with acetic acid (VIA). Screen positive women are referred to respective study hospitals for colposcopy and directed biopsy. Participants with confirmed high-grade cervical dysplasia (high-grade squamous intraepithelial lesions or HSIL) who fit all other eligibility criteria will be recruited to the study and will receive cryotherapy using CryoPop®, an innovative new cryotherapy device.

DISCUSSION

There is a need to develop an inexpensive, simple, and effective cryotherapy device for use by frontline health care providers at locations where screening and timely treatment can be given, accelerating access to cervical cancer prevention services and minimizing loss to follow-up of women with precancerous lesions who need treatment.

TRIAL REGISTRATION

Clinical Trial Registry - India CTRI/2019/01/017289 ClinicalTrials.Gov number NCT04154644 . Registered on November 6, 2019.

p16/Ki-67 dual staining has a better accuracy than human papillomavirus (HPV) testing in women with abnormal cytology under 30 years old

Due to a high rate of transient human papillomavirus (HPV) infection, HPV genotyping has a low specificity for high-grade cervical lesions, especially in young women. p16/Ki-67 dual immunocytochemical staining can also be used for the detection of oncogenic changes in cervical cells. Our aim was to compare the performance of p16/Ki-67 dual staining and HPV genotyping in the detection of high-grade cervical lesions in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL) on Pap smear. We retrospectively analyzed 310 patients with ASCUS/LSIL on Pap smear, who underwent colposcopy. Among these, 161 patients with suspected lesions detected by colposcopy were referred for biopsy. HPV genotyping by LINEAR ARRAY HPV Genotyping Test (CE-IVD) and p16/Ki-67 dual staining by CINtec PLUS Cytology kit was performed prior to cervical biopsy. The overall sensitivity and specificity of HPV genotyping for the detection of cervical intraepithelial neoplasia (CIN) 2-3 was 79% and 72%, respectively in patients with ASCUS, and 85% and 64%, respectively in patients with LSIL. For p16/Ki-67 test, sensitivity and specificity rate was 66% and 93%, respectively in ASCUS and 59% and 79%, respectively in LSIL group. The specificity of p16/Ki-67 staining was significantly higher in both groups in patients aged <30 years compared to patients >30 years old (p < 0.001). Our results showed that p16/Ki-67 dual staining has a higher specificity compared to HPV genotyping, especially in patients under 30 years old. This indicates the usefulness of p16/Ki-67 testing in the triage of patients with ASCUS/LSIL and <30 years old, prior to referral for colposcopy and biopsy.

The National Institutes of Health Affordable Cancer Technologies Program: Improving Access to Resource-Appropriate Technologies for Cancer Detection, Diagnosis, Monitoring, and Treatment in Low- and Middle-Income Countries

Point-of-care (POC) technologies have proved valuable in cancer detection, diagnosis, monitoring, and treatment in the developed world, and have shown promise in low-and-middle-income countries (LMIC) as well. Despite this promise, the unique design constraints presented in low-resource settings, coupled with the variety of country-specific regulatory and institutional dynamics, have made it difficult for investigators to translate successful POC cancer interventions to the LMIC markets. In response to this need, the National Cancer Institute has partnered with the National Institute of Biomedical Imaging and Bioengineering to create the National Institutes of Health Affordable Cancer Technologies (ACTs) program. This program seeks to simplify the pathway to market by funding multidisciplinary investigative teams to adapt and validate the existing technologies for cancer detection, diagnosis, and treatment in LMIC settings. The various projects under ACTs range from microfluidic cancer diagnostic tools to novel treatment devices, each geared for successful clinical adaptation to LMIC settings. Via progression through this program, each POC innovation will be uniquely leveraged for successful clinical translation to LMICs in a way not before seen in this arena.

The Accuracy of p16/Ki-67 and HPV Test in the Detection of CIN2/3 in Women Diagnosed with ASC-US or LSIL

The objective of this study was to compare the accuracies of double staining for p16/Ki-67 and the molecular test for high-risk HPV (hr-HPV) to identify high-grade cervical intraepithelial neoplasia (CIN2/CIN3) in women with cervical cytology of atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL). Data were collected from 201 women who underwent cervical cytology screening in the Barretos Cancer Hospital and their results were categorized as ASC-US (n=96) or LSIL (n=105). All patients underwent colposcopy with or without cervical biopsy for diagnosis of CIN2/CIN3. The hr-HPV test (Cobas 4800 test) and immunocytochemistry were performed to detect biomarkers p16/Ki-67 (CINtec PLUS test). Two samples (1 ASC-US/1 LSIL) were excluded from the analysis due to inconclusive results of the histologic examination. There were 8 cases of CIN2/CIN3 among 95 women with ASC-US (8.4%), and 23 cases of CIN2/CIN3 among 104 women with LSIL (22.1%). In the group of women with ASC-US, the sensitivity and specificity in diagnosing CIN2/CIN3 were 87.5% and 79.5% for the HPV test and 62.5% and 93.1% for p16/Ki-67. Among women with LSIL, the sensitivity and specificity in the diagnosis of CIN2/CIN3 were 87% and 34.7% for the HPV test and 69.6% and 75.3% for immunocytochemistry. Superior performance was observed for p16/Ki-67 double staining, especially among women under 30 for whom the test had an area under the ROC curve of 0.762 (p<0.001). Both p16/Ki-67 double staining and the hr-HPV DNA test had similar performance in predicting high-grade cervical intraepithelial neoplasia among women with ASC-US. The best performance was observed in women aged >30 years. In younger women (≤30 years) with LSIL, p16/Ki-67 had greater accuracy in identifying precursor lesions. Among women >30 years diagnosed with LSIL, the two methods showed similar performance.

Cervical cancer prevention: immunization and screening 2015

Both primary and secondary prevention of cervical cancer are now available. Immunizations against human papillomavirus (HPV) types 16 and 18 have the potential to prevent 70% of cancers of the cervix plus a large percentage of other lower anogenital tract cancers. Screening guidelines were recently changed to recommend cotesting with cytology plus an HPV test. The addition of HPV testing increases the sensitivity and negative predictive value of screening over the Papanicolaou (Pap) test alone.

Current recommendations for cervical cancer screening: do they render the annual pelvic examination obsolete?

The development of a screening test for cervical dysplasia has been a major force in diminishing the worldwide incidence of invasive cervical cancer. Screening intervals recommended by professional organizations have changed over the past half century. Recognition of the human papillomavirus (HPV) as the causative agent and enhanced understanding of the natural history of HPV and cervical dysplasia in different age groups have prompted the American College of Obstetricians and Gynecologists and other professional societies to defer Pap smear screening to intervals no less than 2 years apart in women 21-29, and every 3 years in women 30 and over assuming no prior history of cervical dysplasia. Screening should start no sooner than age 21. These recommendations more closely resemble those currently practiced in Europe and other parts of the developed world. Those who have undergone hysterectomy no longer need screening unless high-grade dysplasia was present. Although the value of pelvic examination is not debated in women with symptoms referable to the female genital tract, the endorsement by several professional societies of less than annual cervical cancer screening in healthy women also begs the question of whether annual pelvic examination (speculum and/or bimanual examination) benefits asymptomatic women. Some sexually transmitted infections are amenable to self-insertion of a vaginal probe or detectable by voided urine specimen. Bimanual examination is insensitive in detecting early ovarian cancer with a high false-positive rate leading to patient anxiety, excessive diagnostic testing, and unnecessary surgical procedures. Future study should focus on the frequency in which healthy asymptomatic women should undergo pelvic examination.

Oncogenic potential of Human Papillomavirus (HPV) and its relation with cervical cancer

Human Papillomavirus (HPV) is the most common cause of cervical cancer. Cervical cancer being the second most common cancer after lung cancer, affecting women of different age groups; has a prevalence of about 20% in young sexually active women. Among different types of HPV, HPV16 the major strain causing this cancer and is sexually transmitted had been unnoticed for decades. Keeping in mind the multiple risk factors related with cervical cancer such as early age sexual activities, teenage pregnancies, smoking, use of oral contraceptives, having multiple sex partners, hormone replacement therapies and various other unknown factors lead to the onset of the disease. Awareness for various diagnostic procedures such as Pap smears screening prove to be an effective way in eradicating the oncogenic potential of HPV.

HPV testing on self collected cervicovaginal lavage specimens as screening method for women who do not attend cervical screening: cohort study

OBJECTIVE

To determine whether offering self sampling of cervicovaginal material for high risk human papillomavirus (HPV) testing is an effective screening method for women who do not attend regular cervical screening programmes.

DESIGN

Cohort study (the PROHTECT trial). Settings Noord-Holland and Flevoland regions of the Netherlands, December 2006 to December 2007, including 13 laboratories, gynaecologists, and more than 800 general practitioners.

PARTICIPANTS

28 073 women who had not responded to two invitations to the regular cervical screening programme: 27 792 women were assigned to the self sampling group and invited to submit a self collected cervicovaginal sample for HPV testing; 281 were assigned to the recall control group and received a second re-invitation for conventional cytology.

INTERVENTION

Women with a positive result on the high risk HPV test on their self sample material were referred to their general practitioner. Women with abnormal results on cytology were referred for colposcopy. Women with normal results on cytology were re-evaluated after one year by cytology and high risk HPV testing and referred for colposcopy if either result was positive.

MAIN OUTCOME MEASURES

Attendance rate in both groups and yield of cervical intraepithelial neoplasia grade II/III or worse (>or=CIN II/>or=CIN III) in self sampling responders.

RESULTS

The compliance rate in the self sampling group was significantly higher than in the control group (crude 26.6% v 16.4%, P<0.001; adjusted 27.5% v 16.6%, P<0.001). The number of detected >or=CIN II and >or=CIN III lesions in self sampling responders was 99 (1.3%) and 76 (1.0%), respectively. Self sampling responders who had not participated in the previous round of screening (43%) had increased relative risks of >or=CIN II (2.04, 95% confidence interval 1.27 to 3.28) and >or=CIN III (2.28, 1.31 to 3.96) compared with self sampling women who had been screened in the previous round (57%).

CONCLUSIONS

Offering self sampling by sending a device for collecting cervicovaginal specimens for high risk HPV testing to women who did not attend regular screening is a feasible and effective method of increasing coverage in a screening programme. The response rate and the yield of high grade lesions support implementation of this method for such women. Trial registration ISRCTN45527158.

Currently approved prophylactic HPV vaccines

Cervarix and Gardasil are two prophylactic HPV vaccines designed primarily for cervical cancer prevention. Cervarix is effective against HPV-16, -18, -31, -33 and -45, the five most common cancer-causing types, including most causes of adenocarcinoma for which we cannot screen adequately. Gardasil is effective against HPV-16, 18 and 31, three common squamous cell cancer-causing types. In addition, Gardasil is effective against HPV-6 and -11, causes of genital warts and respiratory papillomatosis. The most important determinant of vaccine impact to reduce cervical cancer is its duration of efficacy. To date, Cervarix's efficacy is proven for 6.4 years and Gardasil's for 5 years.

Identification of cervical neoplasia using a simulation of human vision

OBJECTIVE

To determine whether a computer simulation of human vision could detect and discriminate cervical cancer precursors and cancer from normal epithelium.

METHODS

The Georgia Tech Vision (GTV) system was trained to recognize normal and abnormal cervical features. GTV then assessed a new series of images to determine whether it could detect and diagnose cervical neoplasia without any a priori information about the images.

RESULTS

After training on one set and testing on another set of images, GTV demonstrated 100% sensitivity and 98% specificity to detect cervical intraepithelial neoplasia 3 (CIN3). GTV also had 88% sensitivity and 93% specificity to detect cervical cancer following training on one set and testing on another set of digitized cervical colposcopic images.

CONCLUSION

This study demonstrated that GTV can detect CIN3 and cancer from digitized cervical colposcopic images. Furthermore, GTV could discriminate cervical cancer precursors and cancer from normal cervical epithelium, including immature metaplasia.

Preventing cervical cancer: the Pap test and the HPV vaccine

Women look to their internists and other primary care physicians to provide preventive health care. Periodic Pap tests are as much a part of a woman's ongoing health care as periodic lipid assessments, mammograms, screening for colon cancer, or any of the other recommended screening assessments. This article provides primary care physicians with the information needed to perform Pap tests at the appropriate intervals, or if not set up to do Pap tests themselves, to make the appropriate referrals. Also provided is the necessary information to counsel women with abnormal Pap tests who may need colposcopy or other follow-up evaluation. Finally, the role of the HPV vaccine in the prevention of cervical cancer is summarized.

Sentinel lymph node detection in early stage uterine cervix carcinoma: A systematic review

OBJECTIVE

The aim of this study was to systematically review the diagnostic performance of Sentinel Node (SN) detection for assessing the nodal status in early stage cervical carcinoma, and to determine which technique (using blue dye, Technetium-99m colloid (99mTc), or the combined method) had the highest success rate in terms of detection rate and sensitivity.

METHODS

A comprehensive computer literature search of English language studies in human subjects on Sentinel Node procedures was performed in MEDLINE and EMBASE databases up to July 2006. For each article two reviewers independently performed a methodological qualitative analysis and data extraction using a standard form. Pooled values of the SN detection rate and pooled sensitivity values of the SN procedure are presented with a 95% confidence interval (95% CI) for the three different SN detection techniques.

RESULTS

We identified 98 articles, and 23 met the inclusion criteria, comprising a total of 842 patients. Ultimately, 12 studies used the combined technique with a sensitivity of 92% (95% CI: 84-98%). Five studies used 99mTc-colloid, with a pooled sensitivity of 92% (95% CI: 79-98%; p=0.71 vs. combined technique), and four used blue dye with a pooled sensitivity of 81% (67-92%, p=0.17 vs. combined technique). The SN detection rate was highest for the combined technique: 97% (95% CI: 95-98%), vs. 84% for blue dye (95% CI: 79-89%; p<0.0001), and 88% (95% CI: 82-92%, p=0.0018) for 99mTc colloid.

CONCLUSION

SN biopsy has the highest SN detection rate when 99mTc is used in combination with blue dye (97%), and a sensitivity of 92%. Hence, according to the present evidence in literature the combination of 99mTc and a blue dye for SN biopsy in patients with early stage cervical cancer is a reliable method to detect lymph node metastases in early stage cervical cancer.

Human papillomavirus testing on self-sampled cervicovaginal brushes: An effective alternative to protect nonresponders in cervical screening programs

Women not attending cervical screening programs are at increased risk of cervical cancer. We investigated in these nonresponders to what extent offering self-sampling devices for cervicovaginal brushes for high-risk human papillomavirus (hrHPV) testing would induce participation and, if so, what the yield of precursor (i.e. CIN2 or worse) lesions following self-sampling would be. In addition, we assessed screening history of participants and costs per detected high-grade CIN2 or worse ("CIN2+") lesion in comparison to the regular program in the Netherlands. Nonresponders received a device for hrHPV testing (self-sampling group, n=2,546) or an extra recall for conventional cytology (control group, n=284). The percentage of self-sampling responders were compared with responders in the recall group. hrHPV positive self-sampling responders were invited for cytology and colposcopy. CIN2+ yield and costs per detected CIN2+ were evaluated. Active response was higher in the self-sampling than in the control group (34.2 vs. 17.6%; p<0.001). hrHPV positive self-sampling responders were less likely to have a prior screening history than screening participants (p<0.001), indicating that they are regular nonresponders. hrHPV prevalence was similar (8.0 vs. 6.8%; p=0.11), but CIN2+ yield was higher in self-sampling responders compared to screening participants (1.67 vs. 0.97%; OR=2.93, 95% CI 1.48-5.80; p=0.0013). Costs per CIN2+ lesion detected via self-sampling were in the same range as those calculated for conventional cytological screening (euro 8,836 vs. euro 7,599). Offering self-sampling for hrHPV testing in nonresponders is an attractive adjunct to effectively increase population coverage of screening without the adverse effect of markedly increased costs per detected CIN2+ lesion.

Evaluation of HPV 16 PCR detection in self- compared with clinician-collected samples in women referred for colposcopy

OBJECTIVES

A clinical prospective evaluation study was conducted to evaluate PCR detection of high-risk human papillomavirus (HPV) type 16 in self-sampled vaginal compared with clinician-collected cervical specimens.

METHODS

Paired vaginal and cervical specimens were collected from 137 consecutive women referred for colposcopy because of abnormal cervical cytology. In-house and a commercial PCR method for HPV type 16 were used. Self-sampled vaginal HPV 16 detection was compared to histology and physician-collected cervical specimens.

RESULTS

Of the 137 patients, 98 had proven abnormal histology and were included in the analysis. Overall, using the cervix HPV detection as reference method, the self-sampled vaginal sample showed sensitivity 91.8%, specificity 96.1% and agreement kappa (kappa) 0.881. Using the histology as reference, all 11 cervical cancer cases were HPV-16-positive in both cervical and vaginal samples, and in 43 high-grade lesions, detection sensitivity in cervix was 72.1% (kappa 0.588) and vagina 67.4% (kappa 0.516). HPV 16 detection did not differ (P=0.27) between clinician-collected cervical and self-sampled vaginal specimens.

CONCLUSIONS

The self-collected vaginal sample is highly concordant with the physician-collected cervical sample in HPV 16 detection.

High concordance of results of testing for human papillomavirus in cervicovaginal samples collected by two methods, with comparison of a novel self-sampling device to a conventional endocervical brush

A user-friendly self-sampling method for collecting representative cervical cell material would lower the threshold for women to respond to the invitation for cervical screening. In the present article, we introduce such a device; we have evaluated its sensitivity and specificity to detect high-grade cervical intraepithelial neoplasia (CIN), via high-risk human papillomavirus (hrHPV) detection and liquid-based cytology (LBC), compared to endocervical brush samples obtained by gynecologists. Women who had a cervical smear reading of moderate dyskaryosis or worse or a repeat equivocal Pap smear result in the cervical screening program (n=64) and healthy volunteers (n=32) took a self-obtained sample at home prior to their visit to the gynecological outpatient department. At the outpatient department, an endocervical brush smear was taken, followed by colposcopy and biopsy whenever applicable. Both self-obtained samples and endocervical brush samples were immediately collected in Surepath preservation solution and used for LBC and hrHPV testing (by general primer-mediated GP5+/6+PCR). hrHPV test results showed a good concordance between the two sample types (87%; kappa=0.71), with sensitivities for prevalent high-grade CIN that did not differ significantly (92% and 95%; P=1.0). The hrHPV test on self-obtained samples proved to be at least as sensitive for high-grade CIN as cytology on endocervical brush samples (34/37 versus 31/37; P=0.5). LBC showed a poor concordance between self-obtained and endocervical brush samples (60%; kappa=0.27). In conclusion, self-obtained samples taken by this novel device are highly representative of the hrHPV status of the cervix. In combination with hrHPV testing, the use of this device may have implications for increasing the attendance rate for cervical screening programs.

Effects of HPV detection in population-based screening programmes for cervical cancer; a Dutch moment

Presently, large randomised studies are investigating the value of incorporating HPV detection in population-based cervical screening programmes to improve the effectiveness of these programmes. None of these studies, however, has assessed the effect of HPV detection on the participation rate of women in these screening programmes. This paper draws attention to the fact that the effectiveness of cervical screening largely depends on the participation rate. A number of possibilities will be addressed on how HPV may affect cervical cancer screening. On the one hand, an option is described that addition of HPV detection, although increasing the sensitivity of screening, may in fact decrease the overall effectiveness of the screening. On the other hand, the possibility is put forward that incorporation of HPV will increase the reduction in mortality because of increased sensitivity and participation to the screening. Our manuscript thereby addresses an important aspect of screening, namely, the societal impact of new diagnostic tests on coverage in population-based screening programmes.

Systems analysis of real-world obstacles to successful cervical cancer prevention in developing countries

Papanicolaou screening is feasible anywhere that screening for cervical cancer, the leading cause of cancer-related death among women in developing countries, is appropriate. After documenting that the Vietnam War had contributed to the problem of cervical cancer in Vietnam, we participated in a grass roots effort to establish a nationwide cervical cancer prevention program in that country and performed root cause analyses of program deficiencies. We found that real-world obstacles to successful cervical cancer prevention in developing countries involve people far more than technology and that such obstacles can be appropriately managed through a systems approach focused on programmatic quality rather than through ideological commitments to technology. A focus on quality satisfies public health goals, whereas a focus on technology is compatible with market forces.

HPV testing in cervical screening

High-risk human papillomavirus (hrHPV) bearing cervical intraepithelial neoplasia (CIN) is considered, as the real precursor lesion of cervical cancer and persistence of an hrHPV infection is necessary for the progression to cervical cancer. This knowledge warrants the use of hrHPV testing as an adjunct to cervical cytology in population-based screening programmes and for monitoring therapy efficacy of high-grade CIN lesions. Replacement of cytology by hrHPV testing altogether is considered, but for this to be (cost-) effective, accurate information about the specificity of the hrHPV test is required. Additional test systems that can be used to stratify women with a positive hrHPV test are HPV genotyping, viral load analysis and hrHPV mRNA analysis. The need for HPV genotyping of cervical smears is illustrated by the increased risk for high-grade cervical lesions associated with HPV types 16 and 18. In particular, for women who have normal but persistently (>1 year) HPV18-positive smears, endocervical curettage is suggested (evidently considering the age and possible future pregnancies of the respective woman) because HPV18 is associated with glandular lesions in the cervix, which are difficult to detect by cytology.

Awareness of general and personal risk factors for uterine cancer among healthy women

Participation rates in gynaecological cancer screening are influenced by different factors. The knowledge of general and personal risk factors for uterine cancer among women might influence their interest in gynaecological cancer screening. Two thousand nine hundred women in 23 gynaecological outpatient services were invited to answer a structured questionnaire regarding general and personal risk factors for cervical and endometrial carcinoma; 2108 women participated. Women with a history of cancer were excluded from the study. It was found that levels of knowledge about uterine carcinoma were low. Only 47.4% of women knew the difference between the sites of origin of cervical and endometrial cancer. Seventy-seven per cent of participants assessed their knowledge about uterine malignancies as insufficient; 96.3% would appreciate more information about uterine cancer. Younger women were significantly less well informed than postmenopausal women. Known risk factors such as smoking or human papillomavirus (HPV) infection as factors for cervical cancer were underestimated; most women assessed genetic factors as most important for the development of uterine cancer. The level of information about risk factors as well as general facts about gynaecological cancer in women is low. Ameliorating this lack of information might influence the perception of uterine cancer and result in higher participation rates in gynaecological cancer screening.

Risk of cervical cancer associated with extending the interval between cervical-cancer screenings

BACKGROUND

Although contemporary guidelines suggest that the intervals between Papanicolaou tests can be extended to three years among low-risk women with previous negative tests, the excess risk of cervical cancer associated with less frequent than annual screening is uncertain.

METHODS

We determined the prevalence of biopsy-proven cervical neoplasia among 938,576 women younger than 65 years of age, stratified according to the number of previous consecutive negative Papanicolaou tests. Using a Markov model that estimates the rate at which dysplasia will progress to cancer, we estimated the risk of cancer within three years after one or more negative Papanicolaou tests, as well as the number of additional Papanicolaou tests and colposcopic examinations that would be required to avert one case of cancer given a particular interval between screenings.

RESULTS

Among 31,728 women 30 to 64 years of age who had had three or more consecutive negative tests, the prevalence of biopsy-proven cervical intraepithelial neoplasia of grade 2 was 0.028 percent and the prevalence of grade 3 neoplasia was 0.019 percent; none of the women had invasive cervical cancer. According to our model, the estimated risk of cancer with annual Papanicolaou tests for three years was 2 in 100,000 among women 30 to 44 years of age, 1 in 100,000 among women 45 to 59 years of age, and 1 in 100,000 among women 60 to 64 years of age; these risks would be 5 in 100,000, 2 in 100,000, and 1 in 100,000, respectively, if screening were performed once three years after the last negative test. To avert one additional case of cancer by screening 100,000 women annually for three years rather than once three years after the last negative test, an average of 69,665 additional Papanicolaou tests and 3861 colposcopic examinations would be needed in women 30 to 44 years of age and an average of 209,324 additional Papanicolaou tests and 11,502 colposcopic examinations in women 45 to 59 years of age.

CONCLUSIONS

As compared with annual screening for three years, screening performed once three years after the last negative test in women 30 to 64 years of age who have had three or more consecutive negative Papanicolaou tests is associated with an average excess risk of cervical cancer of approximately 3 in 100,000.

Comparison of cell collection and direct visualization cervical cancer screening adjuncts

Worldwide, invasive cancer of the cervix is the second most common malignancy in women. Each year, approximately 400,000 women are diagnosed with invasive cancer of the cervix, whereas 200,000 women die from the disease. In the United States, in 2002, there were 12,900 newly diagnosed cases of invasive cervical cancer and 4,400 cervical cancer-related deaths. Data from a recent meta-analysis found that the mean sensitivity of the conventional Papanicolaou (Pap) smear in screening populations was only 47%. These data, and others, underscore the need for more reliable and sensitive methods to screen for cervical cancer precursors. One example is the PapSure screening examination, at this point the only in-office direct visual cervical screening examination cleared by the US Food and Drug Administration. This cervical screening examination combines the traditional Pap smear with a direct visual screening test, speculoscopy (ie, visual inspection of the cervix with a chemiluminescent light, the Speculite).

Reducing death from cervical cancer examining the prevention paradigms

The prevention of morbidity and mortality from cervical cancer will hinge upon our understanding of the epidemiology, the molecular basis, and natural history of the disease and its associated precursors. This article serves as an introduction and presents our current challenge to prevent or find all women at risk, and alter the course of disease to effect a regression or a cure.

Prevention in the year 2002: some news, some issues

As we move into the new century, we continue to focus on ways to prevent disease, promote health, and prolong life. We have made enormous strides in some arenas, including deaths from infectious diseases caused by mass immunization, improved sanitation, better nutrition, heart disease caused by risk factor modification, and some cancers caused by smoking cessation and screening for early detection. Although we have made progress, many challenges remain.

[Cytological history of 148 women presenting with invasive cervical cancer]

OBJECTIVES

The aim of this study was to analyse the cytological history of women presenting with invasive cervical cancer.

MATERIAL AND METHODS

Retrospective study of 148 patients treated for invasive cervical cancer in three hospitals of the North Pas de Calais in France.

RESULTS

The average age of patients was 49 (26-86). Squamous carcinomas represented 81% of cases (120/148), adenocarcinomas 17% (25/148) and adenosquamous carcinomas 2% (3/148). 36.5% of patients (54/148) had never had a Pap smear. 34.5% (51/148) had had an occasional Pap smear (the last one dated of more than three years). 8.1% (12/148) were lost for follow up after a positive Pap smear. 3.4% (5/148) were treated for cervical dysplasia less than three years before the diagnosis of the cervical cancer. 17.5% (26/148) had had a Pap smear reported as negative less than three years before the diagnosis of the cervical cancer. In this last group, squamous carcinomas represented 57.7% of cases (15/26), adenocarcinomas 38.5% (10/26) and adenosquamous carcinomas 3.8% (1/26). 18 Pap smears of 26 reported as negative less than three years before the diagnosis of the cancer were reviewed. These Pap smears came from 11 patients presenting with squamous carcinoma and seven other presenting with adenocarcinoma. After review, 15 Pap smears were reported as false negatives and two as true negatives. The review was not possible in one case.

CONCLUSION

In this study, the failures of cervical cancer screening were essentially attributed to the lack or the insufficiency of screening and the existence of false negatives of the cytology.

Personal view. Is it reality or an illusion that liquid-based cytology is better than conventional cervical smears?

Liquid-based cytology (LBC) has been heralded as the way forward for cervical screening, and as the answer to many of its problems. It is already used as a sole method of cell preparation in many private clinics in the UK. It is being used for colposcopy smears in many NHS clinics and is now being piloted for primary screening in three screening centres in England, as well as one in Scotland and one in Wales. LBC has been welcomed as a new technology because it deals with the problem of specimen adequacy at source, removing responsibility for slide preparation and fixation from the clinician or nurse. It provides uniformly well-fixed preparations that are free of inflammatory exudate and blood, and seem easier to screen than conventional smears. There are many articles in the world literature suggesting that LBC is more accurate than conventional screening, and it is thought likely to reduce the number of false negative tests. The main reasons for piloting LBC in the NHS Cervical Screening Programme (NHSCSP) lie in its potential for reducing screening times and for reducing the numbers of repeats for inadequate tests. LBC is expensive in terms of equipment, capital costs, maintenance, consumables, training, technical preparation time, transportation and disposal of liquid media. Its costs could be justified if they were offset by the money saved from reduced screening time and repeat tests, but only if its accuracy in terms of sensitivity and specificity were proven to be equal to or better than conventional cytology. Although that is generally held to be true by the public and medical profession alike, there is very little hard evidence to support it.

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.