Introduction to the Special Issue: Timely Detection of Cervical Cancer

Transcription

1 Introduction to the Specia Issue: Timey Detection of Cervica Cancer SILVIA C. ROBLES,~ GUEST ED~R THE EPIDEMIOLOGIC PICTURE Every year more than new cases of cervica cancer are reported in the Region of the Americas (I). According to cancer registry data, the owest incidences are found in Canada and the United States, the highest in Peru and Uruguay (2). Cervica cancer is curabe if detected and treated eary; and when this happens generay in a popuation, a decine occurs in the genera mortaity from this cause. As indicated in the first artice of this issue, which describes mortaity trends in the Americas over a period of 33 years, Latin America has been unabe to significanty reduce cervica cancer mortaity, whereas in both Canada and the United States this mortaity is decreasing at a rate of 5% per year. The natura course of cervica cancer is an important eement in designing costeffective prevention and contro programs (3). Previousy, its natura course was described as a sow progression from preinvasive esions and mid, moderate, and acute dyspasias to in situ cancer and, utimatey, invasive cancer. It is now an accepted fact that most dyspasias, or owgrade cervica intraepitheia neopasias (GIN), regress spontaneousy without deveoping into cancer (4); and, accordingy, there is no need to treat a women with this *Pan American Heath Organization, Disease Prevention and Contro Division. Maiing address: 525 Twenty-third Street, N.W., Washington, DC probem. Rather, it is fet that ony highgrade esions constitute true precursor esions that may progress to the point of deveoping into cervica cancer. CINs are, as a rue, fairy frequent. They occur in 5.5% of women between the ages of 20 and 29 and in 2.6% of those between the ages of 50 and 59. It has been a common practice in many countries to treat virtuay a CINs with invasive techniques, such as cervica conization and hysterectomy. The artice by Amie Bishop et ai. in this issue (Cervica Dyspasia Treatment: Key Issues for Deveoping Countries) discusses treatment of CINs and reviews the techniques recommended for outpatient treatment of these neopasias. As a resut of research conducted on the natura course of cervica cancer, over the past severa years it has been possibe to demonstrate a strong causa association between this aiment or its precursor esions and infection with certain types of the human papiomavirus (HPV). It is not enough for a woman to be infected by one of these viruses, however, as other factors are aso associated with cervica cancer (incuding inadequate nutrition with shortages of vitamins C and D, use of ora contraceptives, and mutiparity- 5). In a review artice presented here, Nubia Mtioz and Xavier Bosch confirm the causa association with HI V and assess its impications. Research is currenty being conducted on the deveopment of vaccines against human papiomaviruses, for both prophyactic and therapeutic use, that coud be incuded in future prevention and contro programs. Buetin of PAHO 30(4),

2 In Latin America and the Caribhean, women die annuay fmm cervica cancer. Among the women of Latin America and the Caribbean, cervica carcinoma is the most common type of cancer; and indeed, some of the highest recorded rates of cervica cancer in the word are found in the countries of this region. In most of the countries, mortaity from this type of cancer has remained stabe over the past 30 years, whie in amost a industriaized countries it has decreased steadiy over the same period, thanks to those countries improved abiity to detect and treat cases of the disease. Sixypercent of a//cases of invasive cervica cancer occur in women between the ages of 35and 60. Cervica cancer is not a disease imited to the edery; instead it attacks mature women in the prime of their productive years, who are typicay principa supporters of their famiies. Death from cervica cancer is highest among women with imited access to heath services. The inefficiency of cervica cancertesting programsand their ow yieds resut argey from the practice of giving periodic screening tests mosty to young women at ow risk who seek services in materna heath care and famiy panning cinics. In the process, the opportunity is ostto examine higher-risk women not requesting such services, who tend to seek medica care ony when the disease has aready reached an advanced stage. Athough the risk of deveoping cervica cancer increases with age, it is young women who undergo Pap screening most often, because they can take advantage of prenata or famiy panning medica visits to have the test performed (6). In severa countries where coverage by the Pap test (aso known as the cervica cytoogy test) has been studied, it has been noted that the frequency with which women keep their appointments decreases inversey with age, and that many women over age 50 have never undergone cervica cytoogy screening. Coverage of the femae popuation constitutes the first ink in the organization of an appropriate program. Accordingy, it is no coincidence that four of the studies described in this issue examine such coverage, but from different anges. Two of these (one by Cristiane Nascimento et a. on women in SBo Pauo, Brazi, and the other by Patricia Najera et a. on women in Mexico City and Oaxaca, Mexico) examine how various factors infuence knowedge of the Pap test and whether women in the genera popuation take it. Another, by Ezequie Kimovsky and Eena Matos, makes a simi- ar examination of women being screened for breast cancer in Buenos Aires, Argentina. The ast, by Sivia Lamadrid, ooks into cinic patients knowedge of the Pap test in Santiago, Chie, and fears and other concerns that make it difficut for them to seek testing. WOMEN S ACCESS TO CYTOLOGY SERVICES Athough organization of an eary cervica cancer detection program is a reativey compex medica and institutiona undertaking in its own right, this does not reduce the need to examine the program from the perspective of women. It is aso necessary to recognize, however, that different popuation groups have different degrees of access to heath services, and that women do not behave as a homogeneous group. The study conducted by Fabian Corra et a. in Quito, Ecuador, anayzes the impact of education upon rates of cervica cancer. Of course, whie access to cytoogy services is affected by the socia group to which a woman beongs, there are aso 286 Buetin of PAHO 30(4), 2996

3 The feeings and subjective criteria of women are not taken into consideration and made an integra part of care, even in such difficut situations as when a woman needs to be to/d that cancer has been diagnosed. When they te you that you have cancer, you get a nervous; and even though they expain it quicky, you somehow don t hear. They said Do you have any questions? and I said No, its okay, I understand everything ceary; but I did not understand, and I was so nervous that a I wanted was to eave. They tod me what I had, and I started crying, for bocks and bocks, as if someone had died within me. Peope were ooking at me and my itte gir; I was ooking at the trees, as though I had never seen them in my entire ife. I thought that tomorrow I was going to be dead, and Who woud care for my chidren? I wanted to question the physician, who didn t even ook at me; instead, he said Go outside. * * Matamaa M, Geragosky F, Saazar G, Njhez AL. Caidad de a atencion desde un enfoque de genera. In: Organization Panamericana de a Saud. Mujec Saudy Desarroo. Washington, D.C.: OPS; common obstaces reated specificay to gender issues. In Latin America, there is a need to promote research into both genderreated and other obstaces to cervica cancer screening in different cutura settings. BENEFITS OF AN ORGANIZED EARLY DETECTION PROGRAM The aim of a program for eary cervica cancer detection is to reduce cervica cancer mortaity. Its basic strategy consists of making a screening test avaiabe to the femae popuation, so as to identify those women who might have cancer. This impies that a woman with an abnorma Pap test reading shoud undergo additiona diagnostic procedures in order to rue out or confirm the presence of a maignant tumor or high-grade esion. Once the necessary type of treatment has been determined, it is important that such treatment be avaiabe and affordabe to the woman. Screening tests shoud be subject to strict quaity contro procedures, since both fase positive and fase negative resuts can have serious adverse consequences. Fase positive resuts ead to further diagnostic tests and, occasionay, unnecessary treatments. On the other hand, fase negative resuts represent one of the most difficut probems for any program, as women are ued into a fase sense of security that coud consideraby deay diagnosis and treatment. Many heath services notify the woman ony when the resut of her Pap test is positive. However, in order to encourage adherence to the program, it is important that women aso be notified of negative test resuts and that they be advised these resuts do not competey rue out the possibiity that signs and symptoms of cervica cancer wi appear prior to the next test (7). Two artices in this issue address the question of cytoogy aboratory quaity. The first, by Patricia Aonso et ai., measures interobserver variation between cytotechnoogists; whie the second, by Daia Weissbrod et a., expores the potentia usefuness of an automated screening system. One of the difficuties facing an eary cervica cancer detection program is the high percentage of smears exhibiting infammatory changes, particuary smears obtained from high-risk women who go to cinics to seek diagnosis and treatment of sexuay transmitted diseases. The traditiona recommendation of treatment with fungicides, metronidazoe, topica sufa, or acidifying agents foowed by repetition of the smear may be ineffective if, as shown Robes Infroduction 287

4 by a recent study, such infammations are commony associated with Chamydia trachomatis or Neisseria gonorrheae (8). Obviousy, contro of sexuay transmitted diseases is cosey associated with prevention and contro of cervica cancer. From a of the above, it foows that programs directed at ensuring eary detection of cervica cancer must incude a broad spectrum of components, of which the Pap test itsef is but one. It is necessary to ensure that a women have access to proper treatment-because otherwise the program wi find itsef exposed to serious ethica probems. Aso, since screening reates to an entire process (incuding aboratory processing of the sampe, quaity contro, diagnosis, and treatment) it shoud be stressed that its effectiveness has been demonstrated in severa studies comparing the history of Pap testing among women who had invasive cervica cancer and women of comparabe age who did not. The resuts of these studies show that women who do not undergo Pap testing are at greater risk of deveoping invasive cervica cancer than those who do (g-24), thereby confirming the efficacy of eary detection. Athough we have not incuded in this issue any study evauating eary detection programs, we have incuded the summaries of casecontro studies in which that effectiveness is evauated. We have aso incuded seected artices on difficuties posed by the methods generay used to evauate eary detection programs. ORIENTATION OF THE ISSUE Programs to prevent and contro cervica cancer require participation by a variety of organizations-incuding women s organizations, heath services, associations of professionas participating in the programs, and nongovernmenta organizations engaged in cancer contro efforts. It is essentia when organizing a program that a such entities be brought together in order to reach a consensus on the most appropriate strategies for the particuar country as we as for the various socia contexts invoved. In this monograph issue of the Buetin of the Pan American Heath Organization we have tried to represent the broad spectrum of eements that must be taken into consideration in organizing a program for eary detection of cervica cancer. The most upto-date deveopments in research conducted on the causes of the disease are presented, together with accounts of the various socia factors expaining its distribution and frequency. Advantage is aso taken of the opportunity to disseminate information about work being conducted in the Americas and to identify gaps and questions for which there are as yet no answers, in order to encourage further research and evauation. Identified needs of programs for ear/y detection of cervfca cancer: Increase coverage, overcome the obstaces that hamper efforts to reach women at risk of contracting the disease, and avoid periodic screening of young ow-risk women. Adopt contro measures and improve the quaity of work in cytoogy aboratories throughout the region. Assess the potentia for heath services to respond to the future demand generated by the screening program-because if this is not done, many women, even those with positive Pap test resuts, wi fai to receive either diagnosis or treatment. Strengthen the technica skis of the screening program s heath staff in both administrative and cinica matters. 288 Buetin of PAHO 30(4), 1996

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