Epidemiology. Proceedings of the 12th International Cancer Congress, Buenos Aires, 1978

206 Pages·1979·5.136 MB·English

by  Jillian M. Birch (Eds.)

ADVANCES IN MEDICAL ONCOLOGY, RESEARCH AND EDUCATION
Proceedings of the 12th International Cancer Congress,
Buenos Aires, 1978
General Editors: A. CANONICO, 0. ESTEVEZ, R. CHACON and S. BARG, Buenos Aires
Volumes and Editors:
I - CARCINOGENESIS. Editor: G. P. Margison
II - CANCER CONTROL. Editors: A. Smith and C. Alvarez
III - EPIDEMIOLOGY. Editor: JiUianM. Birch
IV - BIOLOGICAL BASIS FOR CANCER DIAGNOSIS. Editor: Margaret Fox
V - BASIS FOR CANCER THERAPY 1. Editor: B. W. Fox
VI - BASIS FOR CANCER THERAPY 2. Editor: M. Moore
VII - LEUKEMIA AND NON-HODGKIN LYMPHOMA. Editor: D.G.Crowther
VIII - GYNECOLOGICAL CANCER. Editor: N. Thatcher
IX - DIGESTIVE CANCER. Editor: N. Thatcher
X - CLINICAL CANCER - PRINCIPAL SITES 1. Editor: S. Kumar
XI - CLINICAL CANCER - PRINCIPAL SITES 2. Editor: P. M. Wilkinson
XII - ABSTRACTS
(Each voJume is avaiJabJe separately.)
Pergamon Journals of Related Interest
ADVANCES IN ENZYME REGULATION
COMPUTERIZED TOMOGRAPHY
EUROPEAN JOURNAL OF CANCER
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY, BIOLOGY, PHYSICS
LEUKEMIA RESEARCH
ADVANCES IN
MEDICAL ONCOLOGY, RESEARCH
AND EDUCATION
Proceedings of the 12th International Cancer Congress,
Buenos Aires, 1978
Volume III
EPIDEMIOLOGY
Editor:
JILLIAN M. BIRCH
Department of Epidemiology and SociaJ Research
Christie Hospital and Holt Radium institute
Manchester
PERGAMON PRESS
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BritishUbraryCataloluiDIinPubDeatioDData
InternationalCancerCongress,
12th.BuenosAires,1978
Advancesinmedicaloncology,researchand
education.
Vo1.3:Epidemiology
1.Cancer
I. Title II. Canonico,A
III. Birch,JillianM
616.9'94 RC261 79-40693
ISBN0-o8-024386-X
ISBN0-08-023777-0Setof12vols.
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lyandasrapidlyaspossibletheauthors'typescripts
have been reproduced in their original forms. This
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Foreword
This book contains papers from the main meetings of the Scientific Programme
presented during the 12th International Cancer Congress, which took place in Buenos
Aires, Argentina, from 5 to 11 October 1978, and was sponsored by the International
Union against Cancer (UICC).
This organisation, with headquarters in Geneva, gathers together from more than a
hundred countries 250 medical associations which fight against Cancer and organizes
every four years an International Congress which gives maximum coverage to oncological
activity throughout the world.
The 11th Congress was held in Florence in 1974, where the General Assembly unani-
mously decided that Argentina would be the site of the 12th Congress. Argentina
was chosen not only because of the beauty of its landscapes and the cordiality of
its inhabitants, but also because of the high scientific level of its researchers
and practitioners in the field of oncology.
From this Assembly a distinguished International Committee was appointed which under-
took the preparation and execution of the Scientific Programme of the Congress.
The Programme was designed to be profitable for those professionals who wished to
have a general view of the problem of Cancer, as well as those who were specifically
orientated to an oncological subspeciality. It was also conceived as trying to
cover the different subjects related to this discipline, emphasizing those with an
actual and future gravitation on cancerology.
The scientific activity began every morning with a Special Lecture (5 in all), summa-
rizing some of the subjects of prevailing interest in Oncology, such as Environmental
Cancer, Immunology, Sub-clinical Cancer, Modern Cancer Therapy Concepts and Viral
Oncogenesis. Within the 26 Symposia, new acquisitions in the technological area
were incorporated; such acquisitions had not been exposed in previous Congresses.
15 Multidisciplinary Panels were held studying the more frequent sites in Cancer,
with an approach to the problem that included biological and clinical aspects, and
concentrating on the following areas: aetiology, epidemiology, pathology, prevention,
early detection, education, treatment and results. Proferred Papers were presented
as Workshops instead of the classical reading, as in this way they could be discussed
fully by the participants. 66 Workshops were held, this being the first time that
free communications were presented in this way in a UICC Congress.
ix
χ Foreword
The Programme also included 22 "Meet the Experts", 7 Informal Meetings and more
than a hundred films.
METHODOLOGY
The methodology used for the development of the Meeting and to make the scientific
works profitable, had some original features that we would like to mention.
The methodology used in Lectures, Panels and Symposia was the usual one utilized
in previous Congresses and functions satisfactorily. Lectures lasted one hour each.
Panels were seven hours long divided into two sessions, one in the morning and one
in the afternoon. They had a Chairman and two Vice-chairmen (one for each session).
Symposia were three hours long. They had a Chairman, a Vice-chairman and a Secretary.
Of the 8164 registered members, many sent proferred papers of which over 2000 were
presented. They were grouped in numbers of 20 or 25, according to the subject, and
discussed in Workshops. The International Scientific Committee studied the abstracts
of all the papers, and those which were finally approved were sent to the Chairman
of the corresponding Workshop who, during the Workshop gave an introduction and
commented on the more outstanding works. This was the first time such a method had
been used in an UICC Cancer Congress.
"Meet the Experts" were two hours long, and facilitated the approach of young profes-
sionals to the most outstanding specialists. The congress was also the ideal place
for an exchange of information between the specialists of different countries during
the Informal Meetings. Also more than a hundred scientific films were shown.
The size of the task carried out in organising this Congress is reflected in some
statistical data: More than 18,000 letters were sent to participants throughout the
world; more than 2000 abstracts were published in the Proceedings of the Congress;
more than 800 scientists were active participants of the various meetings.
There were 2246 papers presented at the Congress by 4620 authors from 80 countries.
The Programme lasted a total of 450 hours, and was divided into 170 scientific
meetings where nearly all the subjects related to Oncology were discussed.
All the material gathered for the publication of these Proceedings has been taken
from the original papers submitted by each author. The material has been arranged
in 12 volumes, in various homogenous sections, which facilitates the reading of the
most interesting individual chapters. Volume XII deals only with the abstracts of
proffered papers submitted for Workshops and Special Meetings. The titles of each
volume offer a clear view of the extended and multidisciplinary contents of this
collection which we are sure will be frequently consulted in the scientific libraries.
We are grateful to the individual authors for their valuable collaboration as they
have enabled the publication of these Proceedings, and we are sure Pergamon Press
was a perfect choice as the Publisher due to its responsibility and efficiency.
Argentina Dr Abel Canonico
March 1979 Dr Roberto Estevez
Dr Reinaldo Chacon
Dr Solomon Barg
General Editors
Introduction
This volume deals with epidemiology in its broadest sense. A common theme in many
of the papers is the emphasis on the very wide scope for research and the need for
trained research workers in this expanding branch of oncology. This point is
discussed particularly in relation to the countries of Latin America.
An important development in epidemiology is the greater use of laboratory studies
in parallel with traditional techniques. Sero-epidemiological investigations
relating to potential oncogenic viruses and metabolic studies on environmental
carcinogens are included.
The interaction between genetic and environmental factors is discussed and some
important data on occupational carcinogenesis is presented.
JILLIAN BIRCH
March 1979
xi
Panel Chairman's Summary
Gregory T. O'Connor
Co-Chairman: Nubia Munoz
Symposium No. 14 on Cancer Epidemiology was opened by the Chairman,
Dr. G. T. 0'Conor, who emphasized the need for research which focuses on hypoth-
eses concerned with etiologic mechanisms. Epidemiologic research must progress
beyond the establishment and refinement of demographic associations between
cancer types and environmental factors to those sorts of investigations which
utilize a multidisciplinary approach including application of the newest labora-
tory technology.
The Symposium was divided into four parts. The first two sections dealt with
specific aspects of tumor biology in which epidemiologic techniques can be
effectively applied: 1) precancerous lesions and 2) diet and nutrition. In
the third section a presentation and discussion of an ongoing study on colon
cancer proved to be a superb illustration of how a well managed multidiscipli-
nary approach can yield new and relevant information. In the fourth section
several epidemiologists from Latin America outlined and discussed the opportu-
nities for etiologic studies which exist in virtually all of the countries of
Latin America.
Dr. C, Cuello from Cali, Colombia presented morphological evidence for the
relationship of thyroid adenomas to endemic parenchymatous nodular goiter.
These adenomas which represent a neoplastic proliferation of thyroid cells are
of high incidence in areas where goiter is endemic. They also have a higher
prevalence in patients with the follicular and anaplastic types of thyroid
cancer than in the general population or in patients with papillary or medullary
carcinomas.
Dr. C. Marigo from Sao Paulo, Brazil and Dr. E. Sato from Kagoshima, Japan
have extended previous studies which confirm that epithelial dysplasia of the
esophagus, stomach, and large bowel are precancerous changes in these organs.
In the stomach the epithelial changes occur in sites where intestinal meta-
plasia has occurred and in the colon in association with formation of
adenomatous polyps. The degree of dysplasia at all sites can be estimated on
a morphological basis or by measurement of DNA content. The frequency of these
changes as seen in surgical, as well as autopsy material (including Coroner's
cases) correlates with the incidence of invasive cancer at these sites in both
high and low risk populations. The similarity of observations in Brazil and
Japan give further emphasis to the fact that the microenvironment in whiph
3
4 G. T. O'Connor
precancerous lesions develop provides special opportunities for analysis of
the effects of environmental factors which are not possible in population
studies.
In the section on nutrition, Dr. L. Kinlen from Oxford, England described his
studies in nuns and in vegetarians. These population groups have lower
incidence and mortality rates for cancers at certain sites. His comments,
however, and those of the discussants stressed the problems inherent in the
interpretation of these types of studies in respect to choice of controls
and multifactorial influences.
Dr. F. de Waard from Utrecht, The Netherlands briefly reviewed the evidence for
the relation of diet and nutrition to cancer. He pointed out that the etiology
of cancer is more complex than just the introduction of a carcinogen into our
food. Existing knowledge and favored hypotheses suggest an interplay between
extrinsic factors, whether they be naturally occurring or artificially intro-
duced, and a variety of host factors. Professor de Waard has had a special
interest in the effect of overnutrition or obesity on breast and endometrial
cancer. He and his colleagues have shown the relationship between obesity
and extraovarian estrogen production. They are testing hypotheses in the
laboratory and by means of intervention studies which link diet and its effect
on steroid metabolism with cancers of the breast, ovary, endometrium, colon,
and prostate.
Dr. G. Williams from New York, USA, extended the discussion of diet and cancer
into the next section of the Symposium by describing in some detail the multi-
disciplinary studies being carried out on colon cancer by the group at the
American Health Foundation. They have shown that high risk groups in different
countries, but on a Western-type diet, display increased amounts of fecal bile
acid and cholesterol metabolites, increased concentration of intestinal
anaerobic bacteria and fecal mutagens. In addition one low risk group studied
has increased fecal bulk due to dietary fiber content. Extension of these
observations to laboratory studies has shown that rats on a high fat diet are
more susceptible to colon tumor induction, excrete greater quantities of bile
acids and neutral sterols, and that certain bile acids act as tumor promoters.
All these results support the role of dietary fat as a source of tumor promoters
and suggest an antagonistic role for fiber. Dr. D. Thomas of Seattle, Washington
USA, discussed the foregoing paper and outlined the activities of the Breast
Cancer Task Force of the U.S. National Cancer Institute as another example of
a coordinated multidisciplinary approach to cancer epidemiology. The ultimate
objective of these programs dealing with biologic mechanisms is to develop the
knowledge base which will permit the rational design of preventive measures.
In the final part of the Symposium, Dr. J. deSouza from Sao Paulo, Brazil,
Dr. N. Munoz from Lyon, France, and Dr. P. Correa from New Orleans, Louisiana,
USA, described ongoing, as well as projected studies in Latin America which
are directed to specific problems existing in this part of the world. Gastric
cancer and the role of N-nitroso compounds are being investigated in several
high and low risk areas. Latin American coutries with very high rates of
cervical cancer provide a unique opportunity to evaluate screening effects,
as well as to carry out seroepidemiological and other types of studies which
may be expected to provide new information on the natural history of the
disease.
Ethnic as well as specific environmental factors for a number of other cancer
types can be studied with advantage in Latin American countries which show
widely different and variable incidence patterns.
Panel Chairman's summary 5
Dr. deSouza suggested some general guidelines for encouraging epidemiology
research in Latin America.
1. Short courses in cancer epidemiology for pathologists, clinicians, and
surgeons to be sponsored by the appropriate University Medical School
Departments.
2. Better selection of candidates for Schools of Public Health—opportunity
for training should not be limited to "employees of health agencies."
3. Government agencies should support research teams associated with teaching
institutions.
4. Funding for research projects should include fellowship support in order
to encourage the development and training of epidemiologists.
5. International collaboration should be expanded.
Epidemiological Opportunities in
Latin America
Nubia Munoz
International Agency for Research on Cancer, Lyon, France
ABSTRACT
Some of the opportunities for epidemiological research in Latin America are dis-
cussed. Two approaches are used in the pinpointing of these special situations:
1. The identification of populations with high or low rates for specific types of
M
cancer. Using data fromCancer Incidence in Five Continents" and the Inter-
American Investigation of Mortality, research opportunities in cancer of the cervix,
stomach, lung, penis, and other tumours are reviewed. 2. The identification of
population groups exposed to known carcinogens or risk factors. Among the known
carcinogens to which humans are exposed, some pesticides are of special interest in
view of their widespread use in many Latin American countries. Follow-up studies
of population groups occupâtionally exposed to those pesticides will be of great
value in the estimation of their carcinogenic risk for humans.
Key words: Epidemiology: Cervical Cancer: Gastric Cancer:
Pesticides.
Cancer is increasingly recognized in Latin America as an outstanding health problem.
The Inter-American Investigation of Mortality has shown that cancer is the first or
second cause of death at ages 15-74 in ten Latin American cities (Puffer and
Griffith, 1967) . The growing awareness of the magnitude of the cancer problem is
shown by the establishment of a number of cancer divisions or advisory councils in
the Ministries of Health in Latin America, by the launching of national campaigns
against cancer, and by the establishment of national cancer plans to concentrate
resources in the field of cancer treatment and education.
Two approaches could be used in the pinpointing of opportunities for epidemiological
research in Latin America. Firstly, the identification of populations with high or
low rates for specific types of cancer. Secondly, the identification of population
groups exposed to known carcinogens or risk factors. Some of these opportunities
will be reviewed.
POPULATIONS WITH HIGH OR EXCEPTIONALLY LOW RATES FOR CERTAIN
TYPES OF CANCER
Data from "Cancer Incidence in Five Continents", Vol. Ill (1976) and from the Inter-
7