Cervical cancer screening: are the 1989 recommendations still valid? National Workshop on Screening for Cancer of the Cervix.

Although screening for cervical cancer has been shown to be effective in reducing the morbidity and mortality associated with this disease, and despite many attempts to encourage the development of provincial programs, as of 1995 no province had a comprehensive screening program for cervical cancer. Participants at the Interchange ''95 workshop, held in Ottawa in November 1995, reviewed the recommendations of the 1989 National Workshop on Screening for Cancer of the Cervix and identified factors that have impeded their implementation. Participants discussed the need for comprehensive information systems, quality control and strategies to increase recruitment of unscreened and underscreened women. They concluded that the formation of a Cervical Cancer Prevention Network involving key stakeholders will facilitate the development and implementation of provincial programs to ensure optimal screening. They agreed that, in the interim, recommendations for practising physicians should remain as they were following the 1989 workshop.     

Cervical cytology quality assurance in Washington State.

The objectives of this study were to establish a profile of cervical cytology laboratories in Washington State, identify quality assurance problems amenable to correction through education or legislation, and describe differences between large and small cytology laboratories. All 43 Washington laboratories that perform cervical cytology were surveyed by mail during 1989. Completed surveys were returned by 37 (86%) of the laboratories. Nearly half (43%) of the respondents reported processing less than 10,000 Papanicolaou smears annually. Only one-third (35%) of the respondents reported participating in relevant proficiency programs. A proportion of smaller cytology laboratories were compensating their cytotechnologists on the basis of the number of slides read and allowing Papanicolaou smears to be read outside the confines of the laboratory. The results of this study suggest that cytotechnologists in some larger Washington laboratories have been exceeding work load limits recommended by professional associations. Recent legislation includes regulations that address cervical cytology quality assurance. However, continued efforts will need to be made to encourage voluntary adoption of quality control measures not addressed by this legislation.     

Accuracy of registration of invasive cervical cancer.

The quality of the data recorded by the British Columbia Cancer Registry for 521 new cases of invasive cervical cancer was evaluated. The registry''s pathological diagnosis in all new registrations of invasive cervical cancer diagnosed in British Columbia between 1977 and 1979 was compared with a best estimate of the true diagnosis, which was determined from the results of the provincial cervical cytology screening program and the clinical charts at the Cancer Control Agency of British Columbia. The registry''s data overestimated the true incidence of invasive cervical cancer by approximately 55%, since 184 (35%) of the cases were incorrectly registered. Of the 184, 141 (77%) were cases of preinvasive cervical cancer, 26 (14%) did not meet the criteria for a true case (i.e., they were not newly diagnosed in British Columbia between 1977 and 1979) and 17 (9%) were cases of invasive cancer of another primary site. In addition, 28 cases of invasive cervical cancer diagnosed in the province during the study period had not been reported to the registry. Thus, both over-reporting and under-reporting occurred. There is a need for constant evaluation of registry data if cancer registries are to fulfil their potential contribution to cancer control programs and research.     

Why is there no progress against cervical cancer?

The author reflects on the disheartening report given by Dr. E. Jean Parboosingh and associates on Canadian screening programs for cervical cancer (see pages 1847 to 1853 of this issue). Although cancer of the cervix is one of the few preventable forms of cancer, little progress has been made toward the establishment of programs to control this disease. Barriers to progress include a lack of priority given to women''s health issues, insufficient public awareness of cervical cancer, the absence of vocal lobby groups, poor understanding of the limitations of secondary prevention, uncertainty about professional jurisdiction and the financial commitment of government, a tendency for minutiae to deflect attention from essential aims and the sheer complexity of the task of prevention and control. Unless these barriers are overcome it is unlikely that there will be much progress toward the eradication of cervical cancer in Canada.     

Laboratory performance measures: evidence against low-risk women explaining low detection rates of high-grade abnormalities

OBJECTIVE: When a laboratory has a low reporting rate of high-grade abnormality for its cervical cytology specimens, the question arises whether this is due to the laboratory screening a low-risk group of women. This study was undertaken to explore the hypothesis that a low-risk group of women were screened by Victorian laboratories not meeting the recommended minimum standard for the detection of high-grade abnormalities. METHODS: A cohort of 28 094 women was established comprising women whose cervical cytology was reported in 2000 by laboratories not meeting the recommended standard of 0.5% high-grade abnormalities in their reporting of community smears. Outcome measures included the prevalence of high-grade abnormality on the next cytology test for the women, the positive predictive value of the cytology reports of high-grade abnormality, and the standardized incidence ratio for a later diagnosis of cervical cancer. RESULTS: The prevalence of high-grade abnormality was 0.36% on the index cytology compared with 0.68% on the first subsequent cytology report. Sixty-nine per cent (60/87) of the index cytology reports of high-grade abnormality were confirmed as high-grade abnormalities on histology, compared with 70.8% (121/171) for the first subsequent reports of high-grade abnormality. During 70 015 person-years at risk, nine cases of cervical cancer were observed compared with 5.21 expected cases, giving a standardized incidence ratio of 1.73 (95% CI 0.79-3.28). CONCLUSIONS: These results do not support a hypothesis that the low detection rate for high-grade abnormalities is due to the women comprising a low-risk group for cervical neoplasia.     

External quality assurance for cervical cytology in developing countries. Experience in Peru and Nicaragua

Given interest from the professionals concerned, an external quality assurance scheme for cervical cytology can successfully be introduced in developing countries. This is a very important precondition if screening programs are to be expanded and decreases in mortality from cervical cancer are to occur in developing countries. Nicaragua and Peru have been experimenting with an external quality assurance system adapted from the Scottish and Northern Ireland scheme. It has been received with enthusiasm and acceptance and has helped cytology laboratories in these countries focusing on quality issues. Nevertheless, a successful quality control scheme that is to result in improvements in the quality of professionals' diagnostic skills needs to be accompanied by a remedial program for subperformers.     

Cervical cancer screening programs: summary of the 1982. Canadian task force report.

The Canadian Task Force on Cervical Cancer Screening Programs, which produced its first report in 1976, was reconvened by the Department of National Health and Welfare in 1980 in response to concerns expressed about the significance of new data, changing sociosexual patterns and wide variations in the implementation of the 1976 recommendations. This article is a summary of the 1982 task force report. In addition to updates of the 1976 material new sections appear on groups at risk, mathematical models of screening, quality control in screening programs, cytologic screening coverage of the Canadian population and management of patients with abnormal smears. The 1982 recommendations deal with frequency of screening, laboratory quality control and follow-up mechanisms. The task force concludes that measures to improve the quality and sensitivity of screening programs and to include women who have never been screened will be more effective in reducing mortality from carcinoma of the cervix than will attempts to increase the frequency of screening. The task force views as unnecessary the annual screening of women over 35 years of age whose previous smears have been normal. Since younger women are sexually more active and tend to have more than one sexual partner they are at high risk. Therefore, the task force recommends annual screening for sexually active women aged 18 to 35 years. Physicians, health care professionals and government health agencies have a role to play in informing women about the recommended intervals for cervical smears and ensuring that screening programs of adequate quality are available. Although women are primarily responsible for entering and continuing in such a program, government-sponsored registries are essential if the full potential of cervical smear programs is to be realized.     

Laboratory reporting of urine protein and albumin

Communication between pathology laboratories and clients involves more than just a result. There may be advice on recommended specimen type as well as the units and reference intervals used to report results. Between-laboratory variability in these factors has the potential to cause unnecessary confusion and even to lead to variation in interpretation for samples sent to different laboratories. A survey of Australian and New Zealand laboratories covering sample recommendations, specimens received, units and reference intervals for urine albumin and urine protein was conducted through the Royal College of Pathologists of Australasia Quality Assurance Program (RCPA QAP). The results confirm earlier findings of wide between-laboratory variability in all these factors. It is proposed that only recommendations developed by relevant professional societies and adopted by all laboratories can lead to reduction in this variability.     

HPV感染与宫颈癌预防的研究进展

宫颈癌在全球范围内依然是严重威胁妇女健康的常见恶性肿瘤之一。流行病学调查显示,高危型HPV持续感染是导致宫颈癌发病的主要原因,并且HPV感染具有显著的特点,因此,预防HPV感染是防治宫颈癌的主要途径。已明确性行为是促进HPV感染最重要的辅助因子,个体免疫力低下及年龄因素亦是促进HPV感染的重要因素。研究显示,在全球逐渐开展的预防措施包括对常见的高风险HPV类型进行预防性疫苗接种及包括HPV检测在内的宫颈癌筛查项目的实施已经在降低宫颈癌的发病率方面起到了很重要的作用。近些年来,人们越来越重视HPV检测在宫颈癌筛查程序中的应用。由于HPV的感染率具有显著的地域性差异,我们需要针对各地区的特点以完善相应的宫颈癌筛查程序,从而为宫颈癌防治工作的开展提供重要依据。     

Incidence of cervical carcinoma in the Czech Republic

OBJECTIVE: To analyze the incidence of cervical cancer in the Czech Republic. STUDY DESIGN: Investigation of the cause of the unfavorable level of cervical cancer through incidence and laboratory performance. RESULTS: Repeatedly modified screening program measures did not lower the incidence significantly. The incidence in various regions of the Czech Republic differed without fully correlating with patients' life situations. There has been an important shift in incidence toward teenagers and the elderly. Analysis of laboratory work showed that it is necessary to educate smear takers/clinicians and ensure their cooperation with cytology laboratories. CONCLUSION: The various types of screening programs did not lower the cervical carcinoma incidence. It is essential to provide adequate cytologic smears and sufficient laboratory personnel for their proper evaluation.     

National registry of cervical cytologic diagnoses in The Netherlands

The national cervical cytology registry being developed in the Netherlands is described. A large-scale screening program for cervical cancer has been in effect since 1975 in the region of the cities of Nijmegen, Utrecht and Rotterdam. At the start of the pilot projects, laboratories agreed upon a uniform protocol for reporting cytologic findings and recommendations for follow-up examinations in cases of abnormalities. Based on the results of the three pilot projects, in 1985 the Dutch government decided to organize a nationwide screening program for cervical cancer. All pathology laboratories involved in this national screening program are using the same screening protocol and the same coding system for cytologic and histologic diagnoses. By the end of 1989, all pathology laboratories will be linked to a central pathology diagnosis data base (PALGA). Linkage of screening results to previous and follow-up cytologic and histologic findings will enable epidemiologic studies on a regional or national level. Each physician who has submitted specimens will, next to the cytology reports, periodically receive reviews of the number of smears submitted, the cellular composition (quality) of those smears and the follow-up findings. The execution of requests for follow-up examination will be supervised by the participating pathology laboratories. The national cervical cytology registry will enable registration of all relevant cytologic and histologic diagnoses in a uniform way, but will also establish a unique high-quality national data bank, which will be of great value in the analysis of the effectiveness of the national screening program for cervical cancer. It will enable measurement of the impact of various screening protocols and give insight into the behavior of cervical cancer and the progressive or regressive character of its early stages. It will also offer the opportunity to initiate and evaluate quality control protocols.     

Plant molecular biology in Argentina and Chile

We report here on 32 laboratories from Argentina and Chile that include 55 research scientists. Most of these groups were constituted in the last ten years, usually by investigators returning from their postdoctoral training abroad. Some groups are based in institutions with a long tradition in plant biochemistry that are seeking to update their research. Others are organized under the National Institutes for Agronomic Research (INTA in Argentina and INIA in Chile) with the aim of introducing the techniques of molecular biology in their plant breeding programs. Several laboratories sharing similar research interests maintain collaborative links, and many of them participate in binational or multinational research programs. An interesting level, of coordination is provided by REDBIO, the Latin American Network on Plant Biotechnology, which organized national and international meetings in both Argentina and Chile to promote biotechnological research. As a whole, the academic production of these groups has been steadily increasing.     

Preventive practice among primary care physicians in British Columbia: relation to recommendations of the Canadian Task Force on the Periodic Health Examination.

OBJECTIVES: To compare the current practice of preventive medicine in British Columbia with the recommendations of the Canadian Task Force on the Periodic Health Examination. Four common, preventable forms of cancer (cervical, breast, lung and colorectal) were used as sentinel conditions. DESIGN: Random sample mailed survey. SETTING: Private primary care practices in British Columbia. PARTICIPANTS: A sample of 300 primary care physicians in 1991; of 285 eligible physicians 185 (65%) responded. OUTCOME MEASURE: Compliance with preventive practices recommended by the task force. RESULTS: Preventive practice complied with the task force''s recommendations for breast examinations, mammography, cervical smears and initial counselling against smoking; over 90% of the physicians performed these manoeuvres in all or most cases. However, less than half performed two recommended manoeuvres for all or most patients who smoke: advice to follow a diet high in beta-carotene (reported by 10%) and scheduling of follow-up visits to reinforce antismoking counselling (by 46%). Most of the physicians stated that they perform preventive manoeuvres in the context of an annual general physical examination rather than integrating them into routine patient care. CONCLUSIONS: The task force''s carefully constructed recommendations are incompletely followed. Overall, there appears to be a high level of compliance with traditional and recommended manoeuvres but also widespread persistence in performing traditional manoeuvres no longer recommended and failure to adopt new recommendations.     

Reliability and accuracy of reporting cervical intraepithelial neoplasia (CIN) in 15 laboratories throughout Italy: phase 1 of a national programme of external quality control in cervical screening

This paper reports results of a first phase of a pilot study to assess and improve quality of diagnoses in cervical cytological laboratories located throughout Italy. It represents the first phase of an External Quality Assurance programme (EQA). In the first phase, two sets of cervical smears representing a range of diagnoses were circulated among participating laboratories. Responses were recorded on a standardized form. Participants were asked to assess the adequacy of the smear and formulate a diagnosis. They were also asked to recommend management of the patient on the basis of the smear report and judge the degree of diagnostic difficulty of each slide. Crude index of agreement, unweighted and weighted kappas, diagnostic specific kappas, sensitivity and specificity as well as clinical indices of variability were calculated. In the second phase, two additional sets of slides were circulated after discussion of the first phase. There was striking variability between laboratories, both in terms of diagnoses offered and recommendations for management on individual slides. Assessment of the degree of difficulty of each slide was also very variable. Discrimination between CINII and CINIII was poor, confirming the choice of merging these two categories in the Bethesda classification. However, discrimination between CINI and CINII was also unsatisfactory. The results were discussed in workshops and it was possible to reach a consensus diagnosis in 35 of 40 smears. This study confirms the need for external quality control programmes.     

Quality control measures for cervical cytology laboratories

The results of three quality control measures for evaluating a cytopathology laboratory's performance in the diagnosis of cervical abnormalities are presented. The sensitivities of cervical cytology were estimated to be 95.5% or 93.1% (using two different methods of analysis) for the detection of histologically diagnosed invasive squamous cell carcinoma of the cervix and 60% for the detection of adenocarcinoma and adenosquamous carcinoma of the cervix in 1983. The positive predictive values for a histologic diagnosis of neoplasia after cytologic reports of CIN III and invasive carcinoma were 92.5% and 99%, respectively. Repeatability of a negative cytologic result exceeded 98%. These results indicate that accurate cervical cytologic reporting can be achieved. Regular monitoring of the type described, which is both practical and reasonably comprehensive, is recommended for all laboratories.     

Screening for Down's syndrome using serum alpha fetoprotein: a retrospective study indicating caution.

A report was made on the outcome of a four year retrospective study in 27 064 pregnancies, of the clinical efficiency, sensitivity, and specificity of a screening programme for Down''s syndrome based on reported strategies related to the measurement of maternal serum alpha fetoprotein. This study identified 27 pregnancies affected by Down''s syndrome with a median multiple of the median maternal serum alpha fetoprotein concentration of 0.82. This figure is considerably higher than that obtained from previous reports on this subject. With an age related multiple of the median maternal serum alpha fetoprotein strategy, 30.8% of Down''s affected pregnancies were identified as well as 11.6% of unaffected pregnancies. Perhaps a United Kingdom collaborative study should begin to investigate the reasons for such wide population variance in the reports for the median multiple of the median for Down''s affected pregnancies. Until such studies are carried out, screening for Down''s syndrome based on low maternal serum alpha fetoprotein concentration is premature.     

Age at time of first intercourse v. chronologic age as a basis for Pap smear screening.

The Walton Report on cervical cancer screening programs recently recommended a new program for screening for cervical cancer based on chronologic age, calling for 3- and 5-year intervals between examinations. It recommended that such examinations be discontinued after 60 years of age. In a group of 232 routinely examined women (aged 18 to 47 years) in whom cervical intraepithelial neoplasia developed the timing of onset of the disease and the implications for screening were studied. The average age at the time of diagnosis was 30 years; in 20% of the patients the diagnosis had been made after age 35. The screening program recommended in the Walton Report would have been effective in diagnosing most cases (80%) in this sample by age 35 and all by age 60. However, when the patients were grouped according to age at the time of first intercourse, the diagnosis had been made after age 35 in only 13% of those who started having intercourse at age 15 to 17 years, 20% of those who started at age 18 to 19 years and 33% of those who started at age 20 years of later. When the times of diagnosis were expressed by number of years of intercourse the distributions became uniform in the same three groups; in 72% of all the patients the diagnosis had been made within the first 15 years of intercourse, in 88% it had been made within 20 years and in 100% it had been made by 30 years. These data suggest that a program based on number of years of intercourse may be more uniform and more efficient than one based on chronologic age, and that cytologic examinations should be concentrated during the time when most cases develop -- 6 to 20 years after the time of first intercourse.