Lecture 10 Medical and social aspects of oncological

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 90 th 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 approximately 2 – 2. 5 million cases of cancer in India at any given point of time, with around 7. 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 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 90 s 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 1990 s 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.