Validity and reproducibility of cytologic diagnosis in a sample of cervical cancer screening centers in Mexico

The health system and access to treatment in patients with cervical cancer in Mexico

Cervical cancer (CC) is tightly related to a low Human Development Index. Mexico is an upper-middle-income country with 126 million inhabitants, and its public health system aims to provide universal health coverage. Currently, employment-based social insurance covers approximately 60% of the population, and the scope of the remaining 40% is on course via the "IMSS-Bienestar" Institute. However, the annual government spending on health remains at 3% of the Gross Domestic Product, which is well below the 6% recommended by the Organization for Economic Cooperation and Development. CC is the second in incidence and mortality among women. Regarding primary prevention with the Human Papilloma Virus-vaccine, the current coverage for girls aged 9 to 14 years is only around 7%. Among secondary prevention with screening, the program is yet to cover the total number of women at risk; nevertheless, the age-standardized CC mortality rate has decreased from 12 per 100,000 women in 1979 to 5.7 per 100,000 women in 2020 due in part to increased screening coverage. Still, around two-thirds of patients present with locally advanced disease at diagnosis. Data from our country demonstrate that even socially disadvantaged CC patients achieve "standard" survival outcomes if treatment is granted. Nevertheless, there is a shortage in almost every aspect regarding CC treatment, including oncologists, chemotherapy units, medical physicists, radiation technicians, and both teletherapy and brachytherapy facilities. In conclusion, advances in the public health system in Mexico are urgently required to achieve CC control and reduce the mortality from this neoplasia that mainly targets socially disadvantaged women.

Effective methylation triage of HPV positive women with abnormal cytology in a middle-income country

The S5-methylation test, an alternative to cytology and HPV16/18 genotyping to triage high-risk HPV-positive (hrHPV+) women, has not been widely validated in low-middle-income countries (LMICs). We compared S5 to HPV16/18 and cytology to detect cervical intraepithelial neoplasia Grade 2 or worse (CIN2+) and CIN3+ in hrHPV+ women selected from a randomized pragmatic trial of 2661 Colombian women with an earlier-borderline abnormal cytology. We included all hrHPV+ CIN2 and CIN3+ cases (n = 183) age matched to 183 Collapse

Key Words

• DNA methylation
• HPV test
• biomarkers
• cervical cancer
• triage

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MESH Headings

• Adult
• Aged
• Atypical Squamous Cells of the Cervix/pathology
• Atypical Squamous Cells of the Cervix/virology
• Colombia
• DNA Methylation
• Early Detection of Cancer/methods
• Female
• Genes, Viral/genetics
• Humans
• Middle Aged
• Papillomavirus Infections/complications
• Papillomavirus Infections/diagnosis
• Sensitivity and Specificity
• Uterine Cervical Neoplasms/diagnosis
• Uterine Cervical Neoplasms/pathology
• Uterine Cervical Neoplasms/virology
• Uterine Cervical Dysplasia/diagnosis
• Uterine Cervical Dysplasia/pathology
• Uterine Cervical Dysplasia/virology

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Grants

• 16891 Cancer Research UK
• 27046 Cancer Research UK
• C569/A10404 Cancer Research UK

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Affiliation(s)

Arianis Tatiana Ramírez Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Gloria Inés Sánchez Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Belinda Nedjai Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK
María Cecilia Agudelo Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Adam R Brentnall Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK
Kate Cuschieri Queen's Medical Research Institute of The University of Edinburgh, Edinburgh, UK
Kelly Melisa Castañeda Infection and Cancer Group, School of Medicine and Corporación Académica para el Estudio de Patologías Tropicales, Universidad de Antioquia, Medellín, Colombia
Jack Cuzick Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK
Attila T Lorincz Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, UK

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Programmatic human papillomavirus testing in cervical cancer prevention in the Jujuy Demonstration Project in Argentina: a population-based, before-and-after retrospective cohort study

BACKGROUND

Human papillomavirus (HPV) testing for cervical cancer prevention was introduced in Argentina through the Jujuy Demonstration Project (2011-14). The programme tested women aged 30 years and older attending the public health system with clinician-collected HPV tests. HPV self-collection was introduced as a programmatic strategy in 2014. We aimed to evaluate the effectiveness of programmatic HPV testing to detect cervical intraepithelial neoplasia (CIN) of grade 2 or worse (CIN2+) in comparison with cytology-based screening.

METHODS

We did a population-based, before-and-after retrospective cohort study using data from the National Cervical Cancer Prevention Program for the Jujuy province in northwest Argentina. We obtained data for the cytology-based screening period from Jan 1, 2010, until Dec 31, 2011, and for the HPV-based screening period from Jan 1, 2012, until Dec 31, 2014. The primary outcome was detection of histologically diagnosed CIN2+ among women aged 30 years and older. To assess the outcomes in all individuals included in the study, we used multivariable logistic regression and propensity score matching. The reach, effectiveness, adoption, implementation, and maintenance (RE-AIM) framework was used for the before-and-after analysis of programmatic dimensions.

FINDINGS

Of the 29 631 women who underwent cytology-based screening in 2010-11, CIN2+ was detected in 236 (0·8%) individuals. Of the 49 565 women HPV tested in 2012-14 (clinician-collected tests, n=44 700; self-collection tests, n=4865), 693 (1·4%; 658 clinician-collected tests; 35 self-collection tests) were found to have CIN2+ after the first round of screening. Compared with cytology-based screening, the odds ratio of being diagnosed with a CIN2+ lesion was 2·34 (95% CI 2·01-2·73; p<0·0010) with clinician-collected tests, and 1·08 (0·74-1·52; p=0·68) when screened with self-collection tests, after controlling for age and health insurance status. Screening coverage was similar in both periods (52·7% vs 53·2%); improvements of programmatic indicators were observed in the HPV testing period in relation to laboratory centralisation, lower overscreening (6·6% vs 0·0%), higher adherance to age recommendations (79·3% vs 98·8%), and a decrease of inadequate samples (3·6% vs 0·2%).

INTERPRETATION

HPV testing in middle-income settings increases detection of CIN2+ lesions and allows for improvement of programmatic indicators. Evidence suggests that the introduction of HPV testing will accelerate the reduction of cervical cancer burden.

FUNDING

Argentinian National Cancer Institute and National Council of Scientific and Technologic Research.

Factors related to inter-observer reproducibility of conventional Pap smear cytology: a multilevel analysis of smear and laboratory characteristics

OBJECTIVE

To identify factors that influence the inter-observer reproducibility of the routine, conventional Pap smear cytology (Pap smear test) in a network of certificated laboratories in a middle-income Latin American country.

METHODS

Twenty-six laboratories provided each an average of 26 negative for malignancy (NILM) and high-grade squamous intraepithelial lesion (HSIL) Pap smears. An external panel reviewed the slides. The kappa index and multilevel logistic regression were used to estimate the reproducibility and odds ratios (OR) of a false result with 95% confidence intervals (95% CI), respectively. Results are presented for laboratories that collect (collector laboratories) and do not collect (non-collector laboratories) samples.

RESULTS

The agreements ranged widely (median kappa 0.51, range 0.16-0.70). The overall false-positive (FP) and false-negative (FN) rates were 31% (95% CI 27-35) and 11% (95% CI 7-17). Among collector laboratories (N = 14), a bigger sample collection volume decreased the probability of a FP (OR-adjusted 0.05, 95% CI 0.02-0.1) whereas the number of quality defects (OR-adjusted 1.67, 95% CI 1.25-2.24), high workload (OR-adjusted 5.52, 95% CI 3.85-7.92) and collection by cytotechnologists (OR-adjusted 1.28, 95% CI 1.15-1.42) or health professionals (OR-adjusted 2.26, 95% CI 2.04-2.49) instead of nursing assistants increased it. Among non-collector laboratories (N = 9), the FP rate increased with the number of quality defects (OR-adjusted 1.86, 95% CI 1.06-3.26) but decreased if the samples were collected by health professionals instead of nursing assistants (OR-adjusted 0.37, 95%CI 0.17-0.80). No significant associations were observed for FN.

CONCLUSIONS

Staff in charge of cervical sampling significantly determined the reproducibility of the Pap smear test, but this depended on whether the laboratory collects samples or read samples collected elsewhere.

Emelda’s Story: Applying Ethnographic Insights to Cultural Assessment and Cervical Cancer Control

This article builds a bridge between cultural research and clinical practice by applying insights from an ethnographic study of cervical cancer in Iquitos, Peru, to a cervical cancer focused cultural assessment tool and teaching guide for use with immigrant patients. This application is grounded in Campinha-Bacote’s model of cultural competency. Ethnographic research is recommended as a source of knowledge from which insights can be drawn to build assessment skill in cross-cultural clinical encounters—insights into asking the right questions.

Assessment of the Validity and Reproducibility of the Pap Smear in Mexico: Necessity of a Paradigm Shift

BACKGROUND AND AIMS

An assessment was performed of the quality of Pap readings in 19 cytology laboratories (CLs) in Mexico from the Cervical Cancer Screening Program.

METHODS

Nine CLs were affiliated with the Health Ministry (SSA), and ten were affiliated with the Mexican Social Security Institute (IMSS). Two sets of 200 cervical cytology specimens were prepared, one set for each institution. Fourteen percent of the specimens were positive and six were inappropriate for diagnosis (3%). All cervical cytology specimens were processed in the cytopathology laboratory at the General Hospital of Mexico, and histopathology was available for each positive case.

RESULTS

Thirty percent of the SSA reading centers had a sensitivity of at least 80%; however, not one of the ten IMSS laboratories evaluated reached this figure. Some reading centers had a sensitivity <65%, meaning that nearly half of the specimens with a cytology consistent with cervical neoplasm were not identified.

DISCUSSION

Given these results, it is a priority to effect a paradigm shift combining various screening tests to improve adherence to standards and enhanced cost-effectiveness of the early detection of cervicouterine cancer (CC) in Mexico.

Evaluation of a low-cost liquid-based Pap test in rural El Salvador: a split-sample study

OBJECTIVE

We sought to test the diagnostic efficacy of a low-cost, liquid-based cervical cytology that could be implemented in low-resource settings.

MATERIALS AND METHODS

A prospective, split-sample Pap study was performed in 595 women attending a cervical cancer screening clinic in rural El Salvador. Collected cervical samples were used to make a conventional Pap (cell sample directly to glass slide), whereas residual material was used to make the liquid-based sample using the ClearPrep method. Selected samples were tested from the residual sample of the liquid-based collection for the presence of high-risk Human papillomaviruses.

RESULTS

Of 595 patients, 570 were interpreted with the same diagnosis between the 2 methods (95.8% agreement). There were comparable numbers of unsatisfactory cases; however, ClearPrep significantly increased detection of low-grade squamous intraepithelial lesions and decreased the diagnoses of atypical squamous cells of undetermined significance. ClearPrep identified an equivalent number of high-grade squamous intraepithelial lesion cases as the conventional Pap. High-risk human papillomavirus was identified in all cases of high-grade squamous intraepithelial lesion, adenocarcinoma in situ, and cancer as well as in 78% of low-grade squamous intraepithelial lesions out of the residual fluid of the ClearPrep vials.

CONCLUSIONS

The low-cost ClearPrep Pap test demonstrated equivalent detection of squamous intraepithelial lesions when compared with the conventional Pap smear and demonstrated the potential for ancillary molecular testing. The test seems a viable option for implementation in low-resource settings.

Innovation in cervical cancer prevention and control in Mexico

Disparities related to cervical cancer continue to exist in Mexico, including insufficient screening coverage, problems with quality control and a resulting greater risk of mortality among women from marginalized areas. A lack of opportunities and requirements for continuing education and accreditation of healthcare personnel involved in the screening program is also an issue. HPV DNA testing and HPV vaccines are recent technological innovations that offer a potential solution to the continued negative impact of cervical cancer among Mexican women. This essay attempts to answer questions such as: Why should HPV testing be integrated into the early detection program in Mexico? How can HPV testing best be integrated into the program in Mexico? How-from a public health perspective that seeks to reduce disparities-can HPV vaccination best be implemented in Mexico? HPV testing allows increased positive predictive value while also reducing costly and unnecessary overtreatment of low-grade abnormalities, and HPV vaccines offer the possibility of primary prevention of cervical cancer. The strategy proposed for Mexico includes primary prevention with HPV vaccination for girls aged between 12 and 16 years (before sexual initiation), Pap testing with excellent quality control for women 24-34 years of age and high-risk HPV DNA testing for women 35 years and older. HPV samples would be either clinically collected or self-collected and women with positive HPV test results would receive follow-up high-quality Pap testing. This approach is creative and focuses on reducing disparities and providing high-quality care that is also cost effective.

Validation of a low-cost, liquid-based screening method for cervical intraepithelial neoplasia

OBJECTIVE

The objective of the study was to validate a low-cost, liquid-based method for cervical cancer screening.

STUDY DESIGN

We conducted a retrospective, split-sample comparison of 300 liquid-based cervical cytology samples from a group of 150 human immunodeficiency virus-seropositive women and 150 women from low-risk general gynecology clinics whose specimens were screened via standard liquid-based methodology as part of routine care. Residual samples from each specimen were used to prepare a slide using a novel, inexpensive manual membrane method of liquid-based cytology. These slides were screened by a cytotechnologist and abnormal cases were reviewed by a pathologist. Final diagnoses from the manual membrane method of liquid-based cytology slides were compared with the original diagnoses and available cervical biopsy data.

RESULTS

There was good overall agreement between the manual membrane method of liquid-based cytology and original cytology diagnoses (76.3% agreement; kappa = 0.52, 95% confidence interval 0.44 to 0.59). Using available biopsy data to determine the accuracy of each method to identify high-grade squamous intraepithelial lesions, the manual membrane method of liquid-based cytology method was found to have a higher sensitivity (71.4% versus 57.1%) and lower specificity (82.1% versus 89.7%). The slightly higher referral rate to colposcopy using the manual membrane method of liquid-based cytology method was limited to women from the low-risk general gynecology clinics (16.7% versus 12.0%, P = .05).

CONCLUSION

The low-cost manual membrane method of liquid-based cytology cervical cytology method is comparable with a standard commercial method. Consequently, it may be of value in alternative screening strategies in resource-limited settings.

Quality assurance in cervical screening of a high risk population: a study of 65,753 reviewed cases in Parana Screening Program, Brazil

Epidemiological data from the Quality Assurance Unit (QAU) of the Cervical Cancer Screening Program of Paraná is discussed. Slides (65,753) reviewed by the QAU, from October 1997 to July 1999, were analyzed. Relations between agreement rate, diagnostic categories, and age groups were tested. The overall agreement rate was 97.04% (kappa +/- 95%, confidence interval = 0.888 +/- 0.003). Low-grade squamous intraepithelial lesion (LSIL) showed its peak prevalence in patients < or = 19 yr (8.3%). High-grade squamous intraepithelial lesion (HSIL) was more common in women between 40 and 49 yr (5.0%). Squamous-cell carcinoma (SCC) was almost exclusively seen in women > or = 40 yr. The lowest agreement rates were seen in adenocarcinoma (54.5%; kappa = 0.667) and LSIL cases (76.3%, kappa = 0.822), and in women < or = 19 yr (95.8%). It was concluded that constant monitoring to assess specific errors allows directed measures. The 10% rescreening model of quality assurance proved to be effective in a low resources setting with a positive overall financial impact.

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.

Cervical cancer in Iquitos, Peru: local realities to guide prevention planning

Cervical cancer is a major public health problem in Latin America, and in much of the underdeveloped world. This issue has not historically been addressed as a health priority, but in recent years is receiving increased attention and funding. This ethnographic study on the experience of cervical cancer was conducted in Iquitos, Peru, between August 1998 and May 1999. Research methodologies included: (1) observation and household interviews to obtain background knowledge about the region, medical systems, and local cultural understanding of illness; (2) cancer experience interviews; and (3) case studies of women in various stages of cervical cancer or diagnosis. Findings are presented related to local knowledge and experience of Pap smears and cervical cancer and the ineffectiveness of a recently initiated cervical cancer screening program. The findings guide recommendations for interventions in the region in relation to: (1) needed changes in health education, (2) screening frequency and age, (3) sites for screening and treatment, (4) type and availability of treatment, (5) payment issues, (6) documentation of care, and (7) the potential of herbal remedies.

Visual inspection with acetic acid and cytology in the early detection of cervical neoplasia in Kolkata, India

Visual inspection of the cervix after application of 3-5% acetic acid (VIA) is a potential alternative to cytology for screening in low-resource countries. The present study evaluated the performance of VIA, magnified visual inspection after application of acetic acid (VIAM), and cytology in the detection of high-grade cervical cancer precursor lesions in Kolkata (Calcutta) and suburbs in eastern India. Trained health workers with college education concurrently screened 5881 women aged 30-64 years with VIA, VIAM, and conventional cervical cytology. Detection of well-defined, opaque acetowhite lesions close to the squamocolumnar junction; well-defined, circumorificial acetowhite lesions; or dense acetowhitening of ulceroproliferative growth on the cervix constituted a positive VIA or VIAM. Cytology was considered positive if reported as mild dysplasia or worse lesions. All screened women (N = 5881) were evaluated by colposcopy, and biopsies were directed in those with colposcopic abnormalities (N = 1052, 17.9%). The final diagnosis was based on histology (if biopsies had been taken) or colposcopic findings, which allowed direct estimation of sensitivity, specificity, and predictive values. Moderate or severe dysplasia or carcinoma in situ (CIN 2-3 disease) was considered as true positive disease for the calculation of sensitivity, specificity, and predictive values of screening tests. 18.7%, 17.7% and 8.2% of the women tested positive for VIA, VIAM, and cytology. One hundred twenty two women had a final diagnosis of CIN 2-3 lesions. The sensitivities of VIA and VIAM to detect CIN 2-3 lesions were 55.7% and 60.7%, respectively; the specificities were 82.1% and 83.2%, respectively. The sensitivity and specificity of cytology were 29.5% and 92.3%, respectively. All the tests were associated with negative predictive values above 98%. VIA and VIAM had significantly higher sensitivity than cytology in our study; the specificity of cytology was higher than that of VIA and VIAM.

Test characteristics of visual inspection with 4% acetic acid (VIA) and Lugol's iodine (VILI) in cervical cancer screening in Kerala, India

Simple and inexpensive methods based on visual examination of the cervix are currently being investigated as alternative methods of cervical screening. The test characteristics of visual inspection with 4% acetic acid (VIA), and Lugol's iodine (VILI) and conventional cytology were investigated in a cross-sectional study involving 4,444 women aged 25 to 65 years in Kerala, India. While detection of any acetowhite area constituted a low-threshold positive VIA, detection of well-defined, opaque acetowhite lesions close to or touching the squamocolumnar junction constituted a high-threshold positive VIA test. Detection of definite yellow iodine nonuptake areas in the transformation zone close to or touching the squamocolumnar junction constituted a positive VILI test. Cytology was considered positive if reported as atypia or worse lesions. All screened women were evaluated by colposcopy and biopsies were directed in 1,644 women (37.0%), which allowed the direct estimation of sensitivity, specificity and predictive values. The reference diagnosis was based on a combination of histology and/or colposcopy. True disease status was defined as CIN 2 and worse lesions. A total of 149 (3.4%) women had CIN 2 or worse lesions. The sensitivities of low-threshold VIA, high-threshold VIA, VILI and cytology to detect CIN 2 or worse disease were 88.6%, 82.6%, 87.2% and 81.9%, respectively; the corresponding specificities were 78.0%, 86.5%, 84.7% and 87.8%. Our results indicate that VIA and VILI are suitable alternate screening tests to cytology for detecting cervical neoplasia in low-resource settings.

Factors that affect the quality of cytologic cervical cancer screening along the Mexico–United States border

OBJECTIVE

The purpose of this study was to identify the factors that affect the quality of cytologic cervical cancer screening conducted in public sector clinics in Sonora, Mexico.

STUDY DESIGN

We assessed the quality of cervical cytology before and after a 2-hour training session and the implementation of cervical spatulas and endocervical brushes. Additionally, we conducted a cross-sectional study of reproductive aged women who attended public clinics in paired border communities in Sonora and Arizona. Cervical cytologic specimens (n=2436) were collected and compared for adequacy and cytologic diagnosis and for the prevalence of human papillomavirus infection.

RESULTS

The training intervention achieved significantly improved the rates of satisfactory but limited smears and unsatisfactory smears. The cross-sectional study revealed comparable quality indicators for cytologic specimens that were collected in Sonora and Arizona clinics.

CONCLUSION

A high-quality cytology-based cervical cancer screening program is possible in public sector clinics in Sonora, with indicators similar to those achieved in comparable Arizona clinics.

Royal Society of Tropical Medicine and Hygiene meeting at Manson House, London 17 January 2002. Cervical cancer in developing countries

The public health importance of cervical cancer is now increasingly appreciated as a means to improve the general health of women in many developing countries. Developing countries account for 80% of the world burden, mostly due to the lack of effective control programmes. Infection with oncogenic types of human papillomaviruses (HPV) has been established as the central cause for cervical cancer. Thus, vaccination against HPV is a potentially useful strategy for prevention, but this may take several years to become a reality. Currently, early detection and treatment is the most effective approach to control cervical cancer. Cervical cancer may be controlled through improving awareness and accessibility to diagnostic and treatment services. Cytology-based screening is beyond the capacity of health services in many developing countries, hence, alternative methods to cytology are being investigated. Visual inspection of the cervix after application of 3-5% acetic acid (VIA) seems to be a promising screening test, with a similar sensitivity to that of cytology, but lower specificity. Currently, it is being evaluated for its cost-effectiveness in reducing cervical cancer incidence and mortality in randomized trials. Information from the ongoing studies will be valuable for evolving cervical cancer control policies and programmes in low-resource settings.

Evaluation of downstaging in the detection of cervical neoplasia in Kolkata, India

Unaided visual inspection or "downstaging" has been suggested as a potential alternative method for cervical cancer screening in developing countries. Our study was designed to evaluate the accuracy of downstaging to detect cervical neoplasia in a low-resource setting. A total of 6,399 women aged 30-64 years were screened with downstaging by trained nonmedical health workers. Two thresholds were used to define positive downstaging: "low threshold" when any visible abnormality on the cervix was considered positive and "high threshold" when selected abnormalities such as bleeding on touch, bleeding erosion, hypertrophied oedematous cervix, congested stippled cervix and growth or ulcer constituted the positive test. All women underwent a colposcopy examination. Biopsies were directed when colposcopy revealed abnormal lesions. True disease status was defined as histologically proven moderate dysplasia and worse lesions. Since all the participants received a diagnostic (reference) investigation (biopsy and/or colposcopy), sensitivity, specificity and predictive values were estimated directly. Low- and high-threshold downstaging were positive in 1,585 (24.8%) and 460 (7.2%) women, respectively. The sensitivities of low- and high-threshold downstaging to detect high-grade precursors and invasive cancers were 48.9% and 31.9%, respectively. The specificities were 75.8% and 93.3%, respectively. These results indicate that downstaging is not suitable as an independent primary screening modality for cervical neoplasia.

The acceptability of self-collected samples for HPV testing vs. the pap test as alternatives in cervical cancer screening

OBJECTIVE

To explore the acceptability of the self-collection of samples for human papillomavirus (HPV) testing in comparison with that of the Pap test.

METHODS

The study population consisted of 1069 women 20 years and older who were eligible for coverage through the Mexican Institute of Social Security (IMSS). These women were randomly selected among participants in a larger study to evaluate the use of HPV testing as an alternative in cervical cancer screening. All participants provided a self-collected vaginal sample for HPV testing according to explicit instructions and underwent a Pap test. Afterwards, each woman was interviewed about her experience and opinion regarding the two procedures. Acceptability was measured by a calculated score based on discomfort, pain, embarrassment, privacy, perception of personal treatment during the Pap test, and understanding of how to perform the self-sampling method.

RESULTS

Ninety-three percent of women experienced sufficient privacy with the Pap test, whereas 98% of women reported that privacy with the self-sampling procedure was acceptable. The Pap test consistently provoked more discomfort, pain, and embarrassment than self-sampling. Sixty-eight percent of the women who indicated a test preference chose self-sampling. Preference for this method was positively associated with monthly household income. Women reported a preference for self-sampling because it is more comfortable (71.2%) and causes less embarrassment (55.8%).

CONCLUSIONS

Self-sampling is more acceptable than the Pap test and could improve coverage rates of early detection programs. The incorporation of self-collected samples to detect HPV could encourage participation in screening programs among those women who reject the Pap test because of the necessary pelvic examination.

The positive experience of screening quality among users of a cervical cancer detection center

BACKGROUND

Our objective was to determine the main factors associated with increased utilization of a cervical cancer screening program (CCSP) in a population with a high mortality rate due to cervical cancer.

METHODS

A population-based study was carried out in the Mexican state of Morelos, Mexico. The study population included 3,197 women between the ages of 15 and 49 years who were selected at random using a State Household Sampling Framework in the State of Morelos's 33 municipalities. The sample included 2,094 women with a history of a previous Papanicolaou (Pap) test.

RESULTS

A previous experience of good screening quality is strongly associated with greater use of the CCSP (OR = 4.2; 95% confidence interval [CI], 1.6-10.9). The educational level of the head of the family is related to more frequent use of Pap smear services. Women whose husbands have 13 or more years of education (OR = 1.8; 95% CI 1.1-2.9) were more likely to have been screened. Similarly, women who had used two or more family planning methods (OR = 1.6; 95% CI 1.2-2.1) and those who knew why the Pap test was given (OR = 3.0; 95% CI 2.1-4.3) had a better history of Pap screening.

CONCLUSIONS

In areas where coverage of cervical cancer screening is low, a CCSP that guarantees the quality of all the different elements of care is essential if obstacles to cervical cancer prevention are to be eliminated. It is of particular importance to take into account and satisfy the perceptions and expectations of the women at risk.

Asian-American variants of human papillomavirus 16 and risk for cervical cancer: a case-control study

BACKGROUND

Human papillomavirus 16 (HPV16) has a number of variants, each with a different geographic distribution and some that are associated more often with invasive neoplasias. We investigated whether the high incidence of cervical cancer in Mexico (50 cases per 100 000 women) may be associated with a high prevalence of oncogenic HPV16 variants.

METHODS

Cervical samples were collected from 181 case patients with cervical cancer and from 181 age-matched control subjects, all from Mexico City. HPV16 was detected with an E6/E7 gene-specific polymerase chain reaction, and variant HPV classes and subclasses were identified by sequencing regions of the E6 and L1/MY genes. Clinical data and data on tumor characteristics were also collected. All statistical tests were two-sided.

RESULTS

HPV16 was detected in cervical scrapes from 50.8% (92 of 181) of case patients and from 11% (20 of 181) of control subjects. All HPV16-positive samples, except one, contained European (E) or Asian-American (AA) variants. AA and E variants were found statistically significantly more often in case patients (AA = 23.2% [42 of 181]; E = 27.1% [49 of 181]) than in control subjects (AA = 1.1% [two of 181]; E = 10% [18 of 181]) (P<.001 for case versus control subjects for either E or AA variants, chi2 test). However, the frequency of AA variants was 21 times higher in cancer patients than in control subjects, whereas that ratio for E variants was only 2.7 (P =.006, chi2 test). The odds ratio (OR) for cervical cancer associated with AA variants (OR = 27.0; 95% confidence interval [CI] = 6.4 to 113.7) was higher than that associated with E variants (OR = 3.4; 95% CI = 1.9 to 6.0). AA-positive case patients (46.2 +/- 12.5 years [mean +/- standard deviation]) were 7.7 years younger than E-positive case patients (53.9 +/- 12.2 years) (P =.004, Student's t test). AA variants were associated with squamous cell carcinomas and adenocarcinomas, but E variants were associated with only squamous cell carcinomas (P =.014, Fisher's exact test).

CONCLUSIONS

The high frequency of HPV16 AA variants, which appear to be more oncogenic than E variants, might contribute to the high incidence of cervical cancer in Mexico.

Has the use of pap smears reduced the risk of invasive cervical cancer in Guadalajara, Mexico?

In Mexico, cervical cancer is the leading cause of death due to cancer among women 35 years of age and older. Although cytologic screening for cervical cancer was introduced as a national program 24 years ago, the mortality rate for this disease has been increasing. A case-control study was undertaken. Cases were women younger than 70, with newly diagnosed invasive cervical cancer (ICC), who had been residing for at least the past year in the metropolitan area of Guadalajara. They were selected from 5 hospitals belonging to the Mexican National Health System. Controls were women without cervical cancer who were treated in the same health center as the corresponding case. Analysis included 143 cases and 311 controls. Information on risk factors for cervical cancer and prior cervical cytologic screening was obtained through a standardized personal interview. Overall, 54% of the cases reported having had a cervical cytology compared with 82% of controls. When compared with unscreened women, those who had ever had a Pap smear had a significantly lower risk of cervical cancer (OR = 0.3, 95% CI 0.2-0.4), and the protective effect persisted for over 5 years. Utilization of Pap smears in the metropolitan area of Guadalajara exerted a protective effect on ICC. Of the 65 women who reported a negative history of Pap smears, 45 would not have contracted cancer if they had ever had a Pap smear.

Cervical cancer screening in developing countries: why is it ineffective? The case of Mexico

BACKGROUND

Mexico established a national cervical cancer-screening program in 1974. Despite the implementation of the program, there was a steady mortality trend of 16 per 100,000 women over 15 years.

METHODS

A diagnostic procedure of the pitfalls was applied to the following steps of the screening procedure: Pap sampling quality; cytological diagnosis validity; compliance of women; and determinants of non-participation.

RESULTS

The low effectiveness of screening on cervical cancer is principally due to factors associated with quality and coverage. Pap quality is deficient; 64% of a random sample of specimens lacked endocervical cells. Reading centers presented false negative indices of between 10 and 54%. Women seek screening in a late stage of disease (55% with cervical cancer seek care because they have symptoms). In addition, coverage is low; in women between 15 and 49 years of age in Mexico City, 64.2% have a history of Pap, compared with 30% in rural areas. Knowledge of what the Pap is used for strongly determines the use of screening. In rural areas, only 40% of women are informed about the purpose of the Pap test.

CONCLUSIONS

A proposal to reorganize Mexico's screening program includes the following five main strategies: (a) increased coverage; (b) improved quality control of how cervical smears are taken; (c) better interpretation of Pap tests; (d) guaranteed treatment for those whose tests show abnormalities, and (e) improved follow-up.