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Lecture 10
Medical and social aspects of
oncological diseases and
tuberculosis
Problem statement
World
• Cancer afflicts all communities worldwide, approximately 10
million people are diagnosed with cancer and more than 6
million die of the disease every year. In the majority of
economically developed countries malignant neoplasms take the
second place in structure of causes of death, therefore experts
often name them "the murderer № 2", meaning, that "the
murderer № 1" are blood circulation diseases. If at the
beginning of the XX century 3-7% fell to the share of malignant
neoplasms in the structure of causes of death, now they are
consist - 15-20 %. In terms of incidence, the most common
cancers worldwide are lung cancer (12,3% of all cancers), breast
cancer (10,3%) and colorectal cancer (9,4%). For any disease,
the relationship of incidence to mortality is an indication of
prognosis. Similar incidence and mortality rates being indicative
of an essentially fatal condition. Thus, lung cancer accounts for
most deaths from cancer in the world (1,1 million) annually,
since it is most invariably associated with poor prognosis.
Russia
• In Russia within the last 5 years more than 400
thousand persons fall ill with cancer annually; more
than three thousand of them are children. In 2005
three hundred thousand persons were lost due to
malignant neoplasms, or 13,4 % of all dead (the third
place in structure of causes of death). For the last 20
years the number of those died because of malignant
neoplasms constantly grows. So, in 2005, in comparison
with 1990, the death rate index has increased from 194
to 209 per 100 thousand people.
• Despite such high share in the structure of causes of
death, primary morbidity with malignant neoplasms is
insignificant: in 2005 it has made 350 per 100 thousand
population, or 0,7 % of all primary morbidity.
However constant growth of primary morbidity is
observed: in 90th it made 1-2 % a year.
Main causes of primary morbidity:
• The structure of primary morbidity has age and sex features. In
structure of primary morbidity of men the first place is taken
by malignant neoplasms of a trachea, bronchial tubes, lungs (25
%), the second –stomach cancer (13 %), the third – skin
neoplasms (9,5%). In the structure of disease incidence of
women the first place belongs to breast cancer (19,5 %), the
second - to skin neoplasms (14 %), the third – to stomach cancer
(9 %). Level of primary disease incidence of men is higher, than
in women (313,0 against 294,7 per 100 thousand persons).
• For the last five years growth of primary disease incidence with
cancer of colon and rectum, a mammary gland, ovaries,
prostate gland, a bladder, a kidney, skin; and some decrease is
observed in disease incidence of cancer of a lip, a stomach,
respiratory organs. With the years primary disease incidence of
malignant neoplasms increases considerably.
Oncological diseases in Russia
• In total, patients with malignant neoplasms, being registered in
oncological institutions, numbered 1600 per 100 thousand
population by the end of 2005, and this index constantly grows
throughout the last twenty years; and in comparison with 1980,
it has increased almost by 1,8 times. It, on the one hand, speaks
about some successes in treatment of oncological diseases, but,
on the other hand, confirms growth of prevalence of this
pathology. Among the patients registered in oncological
institutions, 31,1 % are patients with mammary gland cancer,
15,8 % –cancer of a cervix of the uterus, 6,5 % –with stomach
cancer, 5,3 % –lung cancer.
• As well as disease incidence, the level and structure of death rate
of this class of diseases are in close dependence on sex and age.
In death rate structure of men the first place occupies cancer of
respiratory system, the second – stomach cancer and the third –
cancer of оesophagus. In the first place women have stomach
cancer, in the second –breast cancer, in the third –cancer of a
cervix of the uterus. Cancer death rate in men is considerably
higher, than in women. Death rate indices grow intensively with
age increase. So, at the age of 60-70 years death rate of men is
100-115 times higher, and at women – 50-60 times higher, than
at persons under 30 years old.
Lethality of malignant neoplasms
• However it is impossible to consider, that the diagnosis of
malignant neoplasms for all patients is fatal. Yes, lethality of
malignant neoplasms is great: one-year lethality (died within the
first year from the moment of diagnosing) makes 36,2 %, and at
separate localizations (cancer of оesophagus, lungs, stomach) it
reaches 57-66 %; at the same time, at such widespread
localization, as mammary gland cancer, one-year lethality is
much more low – 12,6 %. Today 46 % of patients to which the
diagnosis of oncological disease has been made, live 5 years and
more, and at such localization of cancer as cancer of a neck of
the uterus, their number reaches 73 %.
• For the last 10 years the increase of patients recovered from
malignant tumors is noticed; that gives evidence to treatment
efficiency increase. At cancer of trachea, bronchial tubes, lungs this
index has increased from 20,2 to 31,5 %, at throat cancer – from
46,3 to 53,3 %, at cancer of oral cavity and pharynx – from 39,7 to
46,9 %, at malignant lipomas – from 41,2 to 52,0 %.
Medical and social importance of oncological
diseases
• Thus, speaking about cancer epidemiology, it is necessary to
understand, that growth of prevalence of this pathology is
connected both with real increase in its frequency, and with
the subjective reasons, namely: improvement of diagnostics
quality, perfection of statistical records keeping, aging of the
population. Medical and social importance of these diseases is
defined first of all by their great share in the structure of
population mortality, high lethality (including one-year
lethality), high economic losses due to the premature death
rate and invalidism, long and expensive treatment. Special
calculations have shown, that current economic losses due to
malignant neoplasms make over 90 billion roubles a year. At
preservation of current trends to morbidity increase in 2010
the economic damage from neoplasms can reach 180 billion
roubles.
INDIA
• It is estimated that there are approximately 2 – 2.5 million
cases of cancer in India at any given point of time, with
around 7.00.000 new cases being detected each year.
Nearly half of these cases die each year. Although still
lower than in developed countries. The crude incidence
rates of cancer in India varied between 57 and 79 per
100.000 men and 56 and 91 per 100.000 women in urban
registry areas. The crude incidence rate for all cancers at
all sites in rural areas was reported to be 38-46 per 100.000
men and 49-58 per 100.000 women. The four most
frequent cancers in males in India are mouth/oropharynx,
oesophagus, stomach and lower respiratory tract
(trachea/bronchus/lung). For women, cancers of the cervix,
breast, mouth/oropharynx and oesophagus are the most
frequent. A number of these cancers are highly amenable
to primary and secondary prevention.
Primary prevention. Revealing and
elimination of risk factors of this pathology:
1. Control of tobacco and alcohol. Tobacco, which is widely used in
India, is a major cause of cancer of the upper digestive and
respiratory tract. It is estimated that 91 percent of oral cancers are
directly related to the use of tobacco. Excessive intake of alcoholic
beverages is associated with oesophageal and liver cancer.
2. Personal hygiene. Improvements in personal hygiene may lead to
declines in the incidence of certain types of cancer, e.g., cancer
cervix.
3. Occupational exposures. Measures to protect workers from
exposure to industrial carcinogens (cadmium, chromium, vinyl
chloride, asbestos) should be enforced in industries.
4. Foods, drugs and cosmetics. These should be tested for
carcinogens.
The next basic strategic direction in prevention of oncological disease
incidence:
5. Immunization. In the case of primary liver cancer, immunization
against hepatitis B virus and in case of primary cancer cervix,
immunization against human papilloma virus.
Secondary prevention: Early revealing and
radical treatment of precancer diseases.
• Early detection of cases: Cancer screening is the main weapon for
early detection of cancer at a pre-invasive or pre-malignant stage.
Effective screening programmes have been developed for cervical
cancer, breast cancer and oral cancer. Like primary prevention, early
diagnosis has to be conducted on a large scale; however, it may be
possible to increase the efficiency of screening programmes by
focusing on high-risk groups. Clearly, there is no point in detecting
cancer at an early stage unless facilities for treatment and aftercare
are available.
• Treatment: Treatment Facilities should be available to all cancer
patients. Certain forms of cancer are amenable to surgical removal,
while some others respond favourably to radiation or chemotherapy
or both. Since most of the known methods of treatment have
complementary effect on the ultimate outcome of the patient, multimodality approach to cancer control has become a standard practice
in cancer centers all over the world. In the developed countries
today, cancer treatment is geared to high technology. For those who
are beyond the curable stage, the goal must be to provide pain relief.
“Freedom from cancer pain” is now considered a right for cancer
patients (WHO).
• Special oncological vigilance not only by doctors
of all specialities but also by the population is
necessary for lethality decrease of malignant
neoplasms. Considering, that successful treatment
of cancer in many respects depends on timeliness
of its diagnostics, the important role in death rate
decrease should play special, screening routine
examinations of wide contingents of the
population with use of modern medical and
organizational technologies.
Tuberculosis
• Among social diseases tuberculosis takes a special place. The
social nature of tuberculosis is known for a long time. After
revolution in Russia considerable successes in struggle against
tuberculosis have been reached. Tuberculosis morbidity and
mortality of the population steadily decreased. In Russia the
lowest indices of primary disease incidence with tuberculosis
have been noted in 1991: 34,0 persons per 100 thousand, and the
lowest indices of death rates – in 1989: 7,4 per 100 thousand.
However, in the early nineties tuberculosis morbidity and death
rate in the majority of countries of the world began to increase
rapidly.
• At present about one third of the population of our planet is
infected with Mycobacterium of tuberculosis. In 1995 about 9
million persons fallen ill (for the first time) in the world, and
about 3 million patients have died because of this illness.
Mycobacteria of tuberculosis kill more people, than any other
contagium.
Russia
• From the beginning of the 90s in Russia tuberculosis morbidity and
death rate of the population have increased at average by 2,5 times
and have made in 2005: primary disease incidence has made 68
persons per 100 thousand, and death rate – 20,0 per 100 thousand
population. In 2000 the highest levels of tuberculosis morbidity and
death rate have been registered for the last decades: morbidity –
90,4, and death rate – 20,6 per 100 thousand population. Among the
dead 75 % were the persons of able-bodied age. In total in 2005
more than 2200 thousand patients were registered in TB
dispensaries of the country.
INDIA
• India accounts for nearly one-third of global burden of
tuberculosis. Every year, approximately 1.8 million persons
develop tuberculosis of which about 0.8 million are new smear
positive highly infectious cases and 4.17 lakh people die of TB
every year, one person dies every minute, and about 1000 people
die every day.
At the basis of occurrence, development and distribution of
tuberculosis there are three links of a complex epidemic chain:
a source of disease, ways of transmission of infection and a
susceptible collective.
• Source of infection are sick people or animals (more often cattle).
Those who discharge mycobacteria of tuberculosis into environment are
the most dangerous.
• Ways of transfer of tuberculosis are the following: aerogenic (droplet
or air-dust infection), alimentary, contact and pre-natal (from mother to a
fetus through placenta). 95 % of all cases of infection fall to aerosol way.
Mycobacteria of tuberculosis are very stable in the environment – they
easily stand low temperatures (-273 °С), boiling (1-2 mines), survive in
sputum at direct sun rays (15-20 min), they long keep viability and can
cause disease long time intervals later after discharging them by patients.
Alimentary infection is connected with insufficient thermal processing of
the foodstuff received from sick animals (meat, milk and dairy products,
eggs). Children can also be infected alimentary with mother milk. At a
contact way tuberculosis is transmitted through the infected towels, linen,
bedding, and ware.
• The third link of the epidemic chain is a susceptible collective, which
can significantly influence on tuberculosis prevalence. Here the important
role belongs both to the general reactance of an organism of each person,
and specific antituberculous immunity.
The ways of tuberculosis prevention
• Landslide growth of tuberculosis morbidity is connected with all
three links of the epidemic chain. So, a growth of the revealed
for the first time patients discharging mycobacteria of
tuberculosis is characteristic for the modern period. Annually in
Russia about 60 thousand of such patients come to light, even
more than 60 thousand of patients with chronic forms of disease
have discharged mycobacteria of tuberculosis for a long time
already. Thus, in the country there is a huge reservoir of
tubercular infection. Meanwhile one bacillary patient can
contaminate 5-10 persons within a year on the average, and
under certain conditions there can be epidemic eruptions with
infection of 100 persons and more. Hence, one of the ways of
tuberculosis prevention is removing bacillary patients from
hostels and densely populated apartments. However within
1990s this index was reduced from 53,0 to 15,0 %. Eliminators of
bacilli should observe the certain rules, allowing to reduce risk
of infection of associates. However, according to our data, only
less than a half of the patients (48,8 %) observe these rules.
The control of tuberculosis
• The important role in tuberculosis preventive maintenance is
played by its timely revealing. Fluorographic examination,
bacteriological investigation of diagnostic material, routine
inspections have great importance. However during the period
from 1986 till 1997 the number of fluorographically examined
was reduced to 30 million persons, coverage by tuberculosis
routine inspections has decreased from 75 to 59%, the number
of bacteriological researches and tuberculin tests was reduced.
• Special attention of phthisiatricians and therapists is claimed
by persons who can be referred to a group of high risk of
tuberculosis morbidity. Alcoholics, the glue sniffers condemned
and recently released from places of imprisonment are also
referred to them, as well as suffering from chronic nonspecific
diseases of lungs, diabetes, mental frustration, stomach ulcer,
etc. These groups should be revealed and registered by doctors.
Prevention
• For successful carrying out of tuberculosis prevention it is
necessary to pay essential attention to increase of resistance of
the population to infection. Here the important role belongs to
creation of specific antitubercular immunity as a result of
immunization by vaccines BCG and BCG-M.
• The important role belongs to social preventive maintenance in
increase of general reactivity of the organism, decrease in
macroorganism susceptibility to tuberculous infection.
Improvement of conditions and a way of life, stabilization of a
way of life leads to the general increase of protective forces of
the person and tuberculosis susceptibility decrease. Today
growth of tuberculosis morbidity is promoted by the whole
complex of social factors: defective food of the greater part of
the population of the country, growth of alcoholism, narcotism,
HIV-infection, deterioration of living conditions, etc.
Directly Observed Treatment, Shortcourse - DOTS strategy
• For modern tuberculosis it is characteristic that it is caused by
mycobacterium of tuberculosis, having high stability to
antitubercular preparations. At present, more than 10 % of
revealed for the first time patients with the "open" form of
tuberculosis discharge drug-resistant mycobacteria. That’s why
today the WHO has developed special strategy of treatment
tubercular patients – strategy DOTS - Directly Observed
Treatment, Short-course (treatment by short-term courses under
direct supervision of medical workers) which, according to
experts, is economically effective and allowing to reach high
results at treatment of patients. To 1995 80 countries of the world
(including Russia) have introduced or have started to introduce
this strategy.