ical profession and the public. It should be judged as a scientific document, but its recommendations should be judged for what they are: reasonable state-

ments made by competent Canadian physicians for the preservation of the health of Canadian women. DAvm A.E. SHEPHARD

References 1. MACGREGOR JE, Tn'mt S: Screening for cervical cancer. Lancet 1: 1221, 1974 2. Official notice (E). Can Med Assoc 1 1: 57, 1911

The task force on cervical cancer screening programs The decision to establish a task force on cervical cancer screening programs was made by the Conference of Deputy Ministers of Health in December 1973. It was intended to be the first of a series of task forces that would produce "state of the art" reports on certain programs and health care activities whose effectiveness was in doubt. At the first meeting of the task force in June 1974 it was apparent that there was some disagreement among the members concerning the value of cervical cancer screening programs, but such disagreement was resolved by much hard work and many hours of deliberation. The final report represents the unanimous views of the members. The recommendations of the task force deal with such matters as fre-

quency of screening, quality control and follow-up mechanisms. It is the view of the task force that much of the repetitive annual screening of women whose previous smears have been normal is unnecessary. Reduction in the frequency of examination of such women and deployment of resources to concentrate on women at risk who presently are not being screened at all will permit Canadian cervical cancer screening programs to become more effective without utilizing more resources than they do at present. Certain recommendations, such as those dealing with the development of large laboratories and central registries, require implementation by governments. However, the decision to change the frequency of examination will be

implemented only if the health professions and, even more important, the public at large are persuaded that this is a reasonable thing to do. With this in mind, the task force has recommended that the report be widely distributed and publicized and that it be explained to journalists and broadcasters concerned with medical matters. Publication of this report in the Journal is one step in making known the reasoning that has led the task force to make its several conclusions and recommendations on screening programs for cervical cancer. RJ. WALTON, MB, Cli B, FICK

Chairman, task force on cervical cancer Bcreening programs Vice-president, medical Health ScienceB Centre

Winnipeg, MB

Cervical cancer screening programs: a pathologist's viewpoint In the 25 years that screening programs for the detection of precancerous and early malignant lesions of the cervix have been developing in the West, there has been controversy regarding the efficacy of the Pap test in reducing mortality from cancer of the cervix. Although it seems likely that the discussion will continue, a reasonable consensus has been reached, which was concisely expressed in 1972 at a symposium held by the International Union Against Cancer in Sheffield, England.1 At the conclusion of the session on screening for cancer of the cervix agreement was unanimous that "(1) exfoliative cytology of the cervix provides a test of value both in gynecological diagnosis and in screening apparently healthy women, and that a laboratory facility, under a trained cytologist, should be supplied wherever consultative medicine is available; (2) the use of this test as a population screening procedure promises useful yields of pre-invasive or early cancer and potential reduction in mortality. However, to realize this potential and to achieve substantial control of cervical cancer mortality, there must be a well organ-

ized service backed by a research and development effort so that progress can be measured and the service adapted to the needs and circumstances of the particular population." Spriggs2 came to a similar conclusion, adding a special plea that the test should be brought to those women at greatest risk - older women in the lowest social classes - who at present are largely bypassed by screening programs. The comprehensive Walton report that is published in this issue of the Journal summarizes current knowledge and concepts of the epidemiology and natural history of cancer of the cervix. Up-to-date information on screening programs and their effects on the incidence and mortality of carcinoma of the cervix in Canada are reported. Of great interest are the conclusions and recommendations. If implemented, they may lead to a continuing reduction in the mortality from this disease. The recommendation that the lowrisk group of women - the majority of the female population - should be screened once in 3 years, rather than annually, seems sensible and logical in

view of the extremely low detection rate of abnormalities in this group once a patient has had two negative smears. It has obvious economic advantages, which will no doubt be noted by those agencies responsible for funding healthcare programs. However, it is important to realize that reducing the frequency of testing among women who now attend annually does not solve the problem of women who do not get a Pap test because of fear, ignorance or modesty. It has been well established34 that these patients are likely to be older, usually over the age of 45, and in the lower socioeconomic groups. New and effective means must be developed to reach this important segment of the population, in which the majority of new cases of invasive squamous carcinoma of the cervix appear. Part of the solution may lie in the better use of community health resources such as family-planning, well-women, prenatal and venereal disease clinics. Medical students, the family physicians of the future, must be taught the value of the Pap test and when it should be used. If the 3-year screening interval for the low-risk group is accepted, it is

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important that these patients be formally recalled at regular 3-year intervals. Extending the screening interval carries a definite risk that women may forget to return every 3 years. Therefore, the recall system should be operated in each province by means of computerized provincial registries as are recommended in the report. In 1971, almost 2.5 million women had Pap tests in Canada (unpublished data) and the numbers are undoubtedly higher now, so that the logistics of followup will require this approach, already adopted by some provinces. The report recommends that health authorities should support the development of cytologic screening programs designed to detect the precursors of invasive cancer of the cervix, and one recommendation is that, to function efficiently, a laboratory should process at least 25 000 gynecologic smears per annum. While this may be true from an economic viewpoint, the pathologist in many general hospital laboratories in Canada is required to provide a

nongynecologic cytology service for which a trained cytoscreener is required. Thus, many of these laboratories also process a number of gynecologic smears to allow for the employment of a full-time cytotechnologist, since it would be uneconomic to employ such a person for a relatively small, but still essential, number of nongynecologic specimens. From this point of view a minimum of 25 000 gynecologic smears per annum may not be practical in laboratories that fulfil both a service and a screening function. Cancer of the cervix is a preventable disease, but in practical terms it probably cannot be eliminated completely even in a highly developed country such as Canada. Undoubtedly we can achieve better coverage of the population at risk than has been accomplished up to this time. The recommendations in this report, if accepted by government, by the medical profession and by the public, and if acted upon as a unified whole, provide the basis for the establishment of comprehensive screen-

ing programs for carcinoma of the cervix in every province in Canada. These programs would be economically attractive, allowing more effective use of limited resources - money and skilled personnel. The beneficiaries would be the women who as yet have not responded to the publicity surrounding the screening programs. Each year invasive cancer of the cervix develops in many of them, and hence they represent a failure of our present system. G.H. ANDERSON, MB, BS, FRCP[C] Director Section of cytopathology Pathology Institute Halifax, NS

References 1. BOYES DA, KNOWELDEN 3, PHILLIPS Al: The evaluation of cancer control sneaaures. Dr I Cancer 28: 105, 1973 2. S.asoos Al: Population screening by the cervical smear. Nature 238: 135, 1972 3. WAKEFIELD J: Introduction to Seek Wisely to Prevent, London, HMSO, 1972 4. MACGREGOR JE: Evaluation of early detection of cancer of the cervix. Paper, UICS symposium, Sheffield, England, Sept 1972 5. D,.v.soi. RL: Professional and public education in the Manchester region, in Cancer ol the Uterine Cervix, EASSON EC (ed), Toronto, Saunders, 1973, p 121

Cervical cancer screening programs: a gynecologist.s viewpoint Diagnostic cytology for cancer of the cervix was introduced in 1943, when Papanicolaou and Traut published their now famous monograph on diagnosis of uterine cancer by the vaginal smear. It then took several years for the medical profession to appreciate the value of the technique and several more years to convince the public that a Pap test could detect cancer of the cervix in its earliest stage of development. As the Pap test became a routine examination by many doctors treating women, screening programs for the detection of cancer of the cervix developed. Screening for cancer of the cervix has a particularly important advantage over screening for many other malignant conditions: the procedure is based on the detection of precursors of the truly invasive condition, and these precursors may be treated before the invasive malignant disease develops. Over the past 20 years screening has revealed a large number of cases of preclinical disease that could only have been detected by cytologic means. Dysplasia of the cervix, carcinoma in situ and microinvasive cancer of the cervix are all "new" diseases that do not give rise to symptoms. All are limited in extent and can be treated before invasive disease develops. Despite the ability of screening programs to detect cervical cancer and

its precursors, many have questioned whether mass screening is of any real benefit - specifically, does it decrease the incidence of invasive squamous carcinoma and does it decrease the mortality from this disease? Not only do we need answers to these questions but, because screening programs are expensive, their efficiency must be assessed. The value of screening programs for cancer of the cervix has been examined in depth by the task force appointed by the Conference of Deputy Ministers of Health, and this extremely important report, now published in the Journal, contains the evidence to support recommendations made to health authorities and physicians for changing our present routines of mass screening for cervical cancer. Current knowledge, as reviewed in the report, suggests that there are groups of women at different degrees of risk for carcinoma of the cervix. It is imperative that we, as medical practitioners, familiarize ourselves with these groups so that we can identify those most at risk and ensure that they regularly take advantage of screening facilities. Women in the low-risk group should be discouraged from having Pap tests more frequently than once every 3 years. This is a distinct departure from the usual annual Pap test. Current evidence shows, however, that, pro-

982 CMA JOURNAL/JUNE 5, 1976/VOL 114

vided two initial smears are normal, the probability of a subsequent abnormality is less than 0.7/ 1OOO.. Instead of repeating a Pap test in this low-risk group we should turn our attention to those in the high-risk group who are not being screened at all. In this way Canadian screening programs for cervical cancer could become more efficient without any increase in resources. The aim of a screening program is to detect disease at a stage when treatment is likely to be most effective. In the past 20 years there has been much new information regarding precancerous lesions of the cervix such as dysplasia and carcinoma in situ. Of these lesions 75% will eventually progress to invasive carcinoma, the length of time for a severe dysplasia or a carcinoma in situ of the cervix to progress to invasive squamous carcinoma varying from 3 to 20 years.3 But there is no point in detecting a condition if it cannot then be treated. In patients with an abnormal Pap smear, a tissue diagnosis is essential before definitive therapy is undertaken. Colposcopy, a technique developed almost 50 years ago, is proving to be ideal for evaluating the condition of such patients. It defines accurately the most suspicious area of the cervix so that a directed biopsy can be taken and the diagnosis confirmed. The necessity for diagnostic conization

Editorial: Cervical cancer screening programs: a pathologist's viewpoint.

ical profession and the public. It should be judged as a scientific document, but its recommendations should be judged for what they are: reasonable s...
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