Effect of regular 3-yearly screening on the incidence of cervical smears: the Leiden experience

The effect of regular 3-yearly screening over a period of 12 years, on the incidence of cervical cancer in 25,000 women aged 35-54 years, is examined. The rate of squamous cell carcinoma decreased from 0.38 per 1000 women in the first round to zero in the fourth round. Similarly, the rate of carcinoma in situ declined from 1.69 per 1000 women in the first round to 0.35 per 1000 in the fourth round. The rates of severe dysplasia showed no decline. Cytologic under diagnosis of carcinoma-in-situ and cervical carcinoma increased with each round. Widowed and divorced women and those living in urban areas were identified as high risk groups.     

Impact of the Walton report on cervical cancer screening programs in Canada.

It is almost 4 years since the Walton report on cervical cancer screening programs was published. In an effort to assess the impact of this report on such programs across Canada the Department of National Health and Welfare carried out a survey using questionnaires. It appears from the evaluation that physicians, laboratories and provincial departments of health are giving thoughtful but cautious consideration to implementing the report''s recommendations. Stated areas of controversy include the recommended frequency of cervical smear examination, the establishment of province-wide cytology registries and the recommended size of laboratories. Perhaps the pace will quicken as additional knowledge and experience are gained. Perhaps, too, if a national mechanism to encourage provincial implementation were instituted hesitancy would decrease.     

Quality assurance in cervical cancer screening

Objectives. to examine the effectiveness of introducing External Quality Assessment (EQA) into all laboratories which undertake gynaecological cytopathology. to assess pathologists and cytotechnologists regularly for their competence to screen cervical smears, regardless of their standing in the laboratory hierarchy or their experience of gynaecological cytopathology.
Methods. Each participant was asked to screen and report on 10 slides during a 2 h period. the assessment was carried out by a facilitator under the direction of a specially appointed EQA Committee. A maximum score of 20 points was awarded for a completely correct set of answers. A minus score was awarded for a missed abnormal smear. Seventeen pathology laboratories in North West Thames Regional Health Authority participated; 146 cytologists were assessed.
Results. A pilot and four rounds of EQA have been completed and a total 5350 smears examined. Out of 2568 dyskaryotic (abnormal) smears screened, 0.7% were not identified correctly. of the 146 cytologists taking part in the assessment, 95% achieved a score of 17 or more. Three participants were identified who did not reach an acceptable level of competence and appropriate remedial action was taken.
Conclusion. the EQA scheme detected unacceptable levels of performance which can be quickly rectified. Participation of 100% has been maintained on a voluntary basis, and 4 years experience of the scheme confirms that a very high standard of screening prevails in the Region. the study illustrates that voluntary self-regulation is acceptable in the NHS, and the introduction of similar EQA schemes on a national scale will go a long way to establishing confidence in the cervical cancer screening programme.     

A screening system for cervical cancer cytology.

A system for screening cervical cytological preparations is described which employs the Leitz Texture Analyzer System (E. Leitz, Rockleigh, N. J.) quantitative staining with acridine orange, and a fluorescence standard. The instrumentation scans cells on microscope slides and detects objects which it interprets to be nuclei with excess total nuclear green fluorescence intensity (Previous results employing manual measurements have indicated that normal nuclei do not produce total nuclear green fluorescence greater than a specific absolute intensity level). Detected objects are identified by visual observation. Cells (102,000) from 65 patients (29 normal, 36 abnormal) have been examined. In each abnormal sample, at least one abnormal cell was detected. In over half of the samples, three or fewer other objects (e.g. clumps of polymorphonuclear leukocytes) were detected. These are easily distinguishable from single nuclei, and could be discarded by someone with minimal cytological training.     

Uterine cancers in Alberta: trends of incidence and mortality.

Death certificates were reviewed for the 543 Alberta women who died during the period 1969 through 1978 and for whom the underlying cause of death was coded as uterine cancer. To evaluate the recorded cause of death Alberta Cancer Registry records, which existed for 97% of the women, were examined. Calculations from the revised information showed an increase in the mortality of cancer of the corpus uteri and a decrease in the mortality of cancer of the cervix uteri over the 10-year period, but neither was statistically significant. During the same period in Alberta the incidence of cancer of the corpus uteri increased significantly and the incidence of cancer of the cervix uteri decreased significantly.     

A case-control study of cervical cancer screening in north east Scotland.

To estimate the relative risk of invasive cervical cancer in each succeeding year after a negative screening result the screening records of all women tested in the north east of Scotland were examined as the basis for a case-control study. The cases consisted of 115 women in whom invasive cervical cancer had been diagnosed in 1968-82 and who had appeared in the screening records at least once before diagnosis. For each patient five controls were selected from women of the same age who appeared in the screening records before the date of diagnosis in the patient. If the patient''s cancer had been detected by screening the controls were chosen from women of the same age screened the same year. A comparison was made between cases and controls of the number of negative smears taken before the diagnosis. The results showed a high relative protection (inverse of the relative risk) in the first two years after a negative test, falling steadily as time since the last negative test elapsed. Even after 10 years, however, a considerable residual effect was observed.     

HPV testing for cervical cancer screening in Croatia

Opportunistic screening based on the Pap smear has been undertaken in Croatia since 1953. However, cervical cancer remains an important health problem in Croatia when compared to European countries with organised screening programmes. In Croatia, in addition to screening based on well established cytology, Human papillomavirus (HPV) testing is widely used as secondary test as a triage to borderline cytology and as a follow-up after treatment of severe cervical lesions. Many different approaches for HPV testing arose in Croatia over the last decade depending on the needs of each medical institution involved. Presently, there is an urgent need for better networking between the laboratories, the implementation of quality assessment and the adaptation of a uniform system of referring to and reporting of HPV testing. In conclusion, the best possible organisation for HPV testing would be essential for implementation of HPV testing as primary screening test in Croatia, an thus ultimately and hopefully, the more successful cervical cancer control.     

Costs and benefits of cervical screening. I. The costs of the cervical screening programme

In 1991, the average total Health Service cost of a cervical smear, including follow up at the colposcopy clinic, was almost £22.70 in the Perth and Kinross district of Scotland. The average cost per colposcopy clinic visit was £30. The main cost elements were in general practice (55% of total) and the laboratory (33%), and most of the cost was for staff time.     

Feasibility of cytology-based cervical cancer screening in rural Cameroon

OBJECTIVE: To determine the prevalence of cervical cancer and its precursors in a rural population in Cameroon and to evaluate the feasibility of a cytology-based screening program in such areas. STUDY DESIGN: A prospective study was conducted in the rural town of Bafang. Following an advocacy campaign, 750 women were recruited. After a clinical examination, all women had a Pap smear with the Cervex Brush. Each sample had two preparations, conventional and liquid based. The conventional smears were interpreted in Bafang. Cytologically abnormal cases, those with clinical inflammation and/or macroscopic cervical lesions, had a colposcopic examination and directed biopsy. HSIL and colposcopically abnormal cases were treated with large loop excision of the transformation zone (LLETZ). The liquid-based preparations and histopathology were performed in Geneva and the results sent to Cameroon for patient follow-up. RESULTS: Mean age and parity of the women screened were 43.7 years and 7.8, respectively. The conventional smears showed 3.6% cervical abnormalities: 2% (15/740) ASCUS/LSIL and 1.6% (12/740) HSIL. The liquid-based preparations showed 12.6% (91/722) cervical abnormalities: 10.1% (73/722) ASCUS/LSIL and 2.5% (18/722) HSIL. Fifty percent of samples in both preparations showed evidence of inflammation. Histology was performed on 64 colposcopically directed punch biopsies and LLETZ specimens. The histologic diagnoses agreed with the cytologic findings in 60% (14/23) of conventional smears and 85% (12/14) of liquid-based preparations. CONCLUSION: There is a high rate of cervical intraepithelial neoplasia in the unscreened rural population of Cameroon. The situation is complicated by a high rate of cervical infection. A population-based cytologic screening program for cervical cancer would not be feasible in rural Cameroon because of high cost, low quality and limited technical facilities. Rural Africa requires an algorithm using a simple, low-cost technique of mass screening and an improved cytology service only to triage selected patients.     

Screening for squamous cervical cancer: duration of low risk after negative results of cervical cytology and its implication for screening policies. IARC Working Group on evaluation of cervical cancer screening programmes.

A collaborative study of screening programmes in eight countries was performed to estimate the risks of cervical cancer associated with different screening policies. Most of the data came from centrally organised screening programmes. Relative protection was higher in women who had had two or more negative results of screening tests than in those who had had only one negative smear, particularly in the first five years after the last test. There was little difference in the protection afforded by screening every year compared with every three years, but screening only once every five or 10 years offered appreciably less protection. The age of the women did not affect the sensitivity of the test or the sojourn time of the disease (the length of the detectable preclinical phase during which abnormal cytology could be picked up if a smear were taken); invasive cancer in women under 25 was rare. Centrally organised screening programmes were more effective than uncoordinated screening. Screening programmes should be aimed principally at women aged 35-60 but should start some years before the age of 35, and the intervals between screening should be three years or less.