Publication of a cervical The scientific section of this issue of the Journal is devoted to a single im¬ portant public-health topic: the value of cervical screening in the prevention of death among Canadian women from cancer of the cervix. This evaluation is presented as the report of a task force composed of distinguished Canadian physicians. The "Walton report" is of great general interest and of much import because it provides an authoritative review of current knowledge about cervical cancer a disease that has a high mortality, can be treated effec¬ tively if it is diagnosed early and, more important, can be largely prevented by screening. The substance of the report and its conclusions and recommenda¬ tions have much scientific and social significance. For these reasons publica¬ tion of the report in its entirety has been deemed a matter of high priority; the report is, however, lengthy, and some comments concerning its publica¬ tion are in order. In Canada in 1972 uterine cancer was the cause of death in 1046 women; in 600, death was attributed to cancer of the cervix. This statistic is important in itself, but more important is the consideration that, in the absence of screening, the number of Canadian women dying from cancer of the cervix would likely have been of the magni¬ tude reported in the years before screening was implemented. An ex¬ ample of the association of cervical screening and decrease in the mortality of cervical cancer has been provided by MacGregor and Teper,1 who studied the changing incidence of cervical can¬ cer in Aberdeen, Scotland. In that area screening started in 1960, and soon 90% of the population at risk had been screened at least once. Between 1961 and 1971 the rate of overt clinical can¬ cer decreased sharply, so that in 1971 it was less than half the rate reported 10 years earlier. Mortality also de¬ creased: in 1971 the rate for women aged 20 years or over was nearly 30% lower than it had been in 1961. Mac¬
cancer
screening report
Gregor and Teper did not suggest that tially, the program would consist of screening was a proven preventive of two Pap tests 1 year apart, then Pap deaths from cervical cancer but they tests at 3-year intervals (provided ear¬ did make two important points: first, lier smears were normal) to the age in the decade between 1961 and 1971, of 35 years, and then Pap tests at 5169 cases of cervical cancer were de¬ year intervals until age 60. The report tected at the symptomless but micro- complements these clinical recommen¬ invasive stage, so that without diag¬ dations with recommendations concern¬ nosis and treatment the women in ing the efficient processing of smears whom the disease was detected would in laboratories so that cytopathologic probably have died during the late expertise is made readily available and 1960s; and, second, in women in whom follow-up is effective. cervical
cancer
continues to
occur
de¬
spite screening, failure to attend screen¬ ing sessions and technically inadequate smears are pertinent factors. The Walton report is important be¬ cause it puts into focus the situation concerning screening for cervical can¬ cer in Canada. The study by Mac¬ Gregor and Teper is one of a number (many of which are well reviewed by Walton and his colleagues) that indicate that, while cervical cancer screening programs are most important, they do have some drawbacks and imperfections. An obvious problem is that of cost, and the cost-benefit ratio alone justifies a comprehensive study of cer¬ vical cancer screening in Canada. A second problem is reflected in the ob¬ servation that women who are most likely to be at risk are the least likely, for social and educational reasons, to receive the benefits of screening; there are, thus, strong arguments for introducing better screening programs in Canada, if necessary by changing our approach to screening. As a single ex¬ ample, should women necessarily be screened annually? This is the accepted
wisdom at present, but the Walton re¬ port suggests that our resources would be better deployed were the frequency of examination related to the degree of risk rather than to a traditional recom¬ mendation whose basis is not entirely hence the report's recommen¬ sound dation for a specific testing program that would lead to a more frequent finding of cases and, thus, a lower mortality from cervical cancer. Essen¬
The recommendations of the Walton are based on a careful review of many aspects of cancer of the cervix, all of which will interest and inform Canadian physicians. The epidemiology and natural history are discussed in detail; the philosophy of the screening process is considered and screening is looked at from both the Canadian and the international viewpoint; and three groups of women at different degrees of risk are identified. Such a wealth of information constitutes a compact and readily available source of reference that will serve Canadian physicians well and augment the growing international literature on screening and disease. The scientific interest and importance of the Walton report is ample justifica¬ tion for its publication, and its authorship by well qualified Canadian physi¬ cians is consistent with the Journal's objective of publishing what is best in Canadian medicine.2 Free comment, too, has always been welcomed, and in this connection attention should be paid to the report chairman's hope that any recommendations "will only be im¬ plemented if the health professions, and even more important, the public at large are persuaded that this is a reasonable thing to do" (my italics). Scientific advances and public under¬ standing of science are based on reason, and reason must be based on sound information but also on free comment. The Walton report was accepted for publication because it is scientifically important and because its content re¬ quires dissemination, both to the med-
report
CMA JOURNAL/JUNE 5, 1976/VOL. 114 979
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
OMA JOURNAL/JUNE 5, 1976/VOL. 114 981
cancer
screening report
Gregor and Teper did not suggest that tially, the program would consist of screening was a proven preventive of two Pap tests 1 year apart, then Pap deaths from cervical cancer but they tests at 3-year intervals (provided ear¬ did make two important points: first, lier smears were normal) to the age in the decade between 1961 and 1971, of 35 years, and then Pap tests at 5169 cases of cervical cancer were de¬ year intervals until age 60. The report tected at the symptomless but micro- complements these clinical recommen¬ invasive stage, so that without diag¬ dations with recommendations concern¬ nosis and treatment the women in ing the efficient processing of smears whom the disease was detected would in laboratories so that cytopathologic probably have died during the late expertise is made readily available and 1960s; and, second, in women in whom follow-up is effective. cervical
cancer
continues to
occur
de¬
spite screening, failure to attend screen¬ ing sessions and technically inadequate smears are pertinent factors. The Walton report is important be¬ cause it puts into focus the situation concerning screening for cervical can¬ cer in Canada. The study by Mac¬ Gregor and Teper is one of a number (many of which are well reviewed by Walton and his colleagues) that indicate that, while cervical cancer screening programs are most important, they do have some drawbacks and imperfections. An obvious problem is that of cost, and the cost-benefit ratio alone justifies a comprehensive study of cer¬ vical cancer screening in Canada. A second problem is reflected in the ob¬ servation that women who are most likely to be at risk are the least likely, for social and educational reasons, to receive the benefits of screening; there are, thus, strong arguments for introducing better screening programs in Canada, if necessary by changing our approach to screening. As a single ex¬ ample, should women necessarily be screened annually? This is the accepted
wisdom at present, but the Walton re¬ port suggests that our resources would be better deployed were the frequency of examination related to the degree of risk rather than to a traditional recom¬ mendation whose basis is not entirely hence the report's recommen¬ sound dation for a specific testing program that would lead to a more frequent finding of cases and, thus, a lower mortality from cervical cancer. Essen¬
The recommendations of the Walton are based on a careful review of many aspects of cancer of the cervix, all of which will interest and inform Canadian physicians. The epidemiology and natural history are discussed in detail; the philosophy of the screening process is considered and screening is looked at from both the Canadian and the international viewpoint; and three groups of women at different degrees of risk are identified. Such a wealth of information constitutes a compact and readily available source of reference that will serve Canadian physicians well and augment the growing international literature on screening and disease. The scientific interest and importance of the Walton report is ample justifica¬ tion for its publication, and its authorship by well qualified Canadian physi¬ cians is consistent with the Journal's objective of publishing what is best in Canadian medicine.2 Free comment, too, has always been welcomed, and in this connection attention should be paid to the report chairman's hope that any recommendations "will only be im¬ plemented if the health professions, and even more important, the public at large are persuaded that this is a reasonable thing to do" (my italics). Scientific advances and public under¬ standing of science are based on reason, and reason must be based on sound information but also on free comment. The Walton report was accepted for publication because it is scientifically important and because its content re¬ quires dissemination, both to the med-
report
CMA JOURNAL/JUNE 5, 1976/VOL. 114 979
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
OMA JOURNAL/JUNE 5, 1976/VOL. 114 981
