Lung cancer: symptoms, signs, treatment, stages
Lung cancer is one of the most common types of malignant tumors in humans. Today, it ranks first in the world in the number of cases. The main reasons causing swelling, are the inhalation of a variety of carcinogenic substances, Smoking, working in hazardous industries.
The growth of cities, development of heavy and mining industries led to the increase in the number of annually registered cases of neoplasms of the bronchopulmonary system. The atmosphere of Metropolitan areas contains a significant amount of production waste, emissions, road and rail transport, dust and radioactive substances. Work in coal mines, metallurgical industry, chemical plants in the short term can lead to various lung diseases that will later become the sources of growth of cancerous tumors. Manufacture of cotton and linen accompanied by a significant dusting of the premises, which leads to the accumulation of harmful substances and dust in the alveoli.
Among the carcinogens (cancer-causing substances) are dominated by benzpyrene, various nitrosoedinenii, asbestos, radon, arsenic, and others.
Smoking is one of the most powerful factors that cause lung cancer. Almost all cases are or were in the past hard-core smokers. Inhalation of cigarette smoke is accompanied by a hit in the bronchi and the alveoli not only of carcinogens (benzpyrene, benzanthracene), but also a large number of soot and radioactive polonium-210. The latter tends to stay very long in the body and, due to the long half-life, exerts its negative effect even after a long period of time.
For malignant transformation of the epithelium is also the experience of Smoking and its intensity: the longer a person smokes and the more cigarettes consumed at the same time, the higher the risk. Of particular danger are products of the tobacco industry are of low quality and without a filter, leading to the immediate contact with all sorts of hazardous compounds into the lungs.
Do not forget about passive Smoking. In Smoking families, the risk of lung cancer among non-members increases in half to two times. Being in a car with a smoker even within the hour contributes to the risk of developing the disease.
In addition to the aerogenic route, it is also possible the ingress of harmful substances into the lungs through the blood. In such cases, it often develops so-called peripheral cancer arising from the epithelium of small bronchioles or alveoli.
The disease is recorded more often in males and usually older than 60 years, however, as in the case of tumors of other localizations, there is a tendency to «rejuvenation». Males more exposed to harmful external factors, and therefore the risk of disease is much higher.
In women, lung cancer is found according to various reports 8-10 times less frequently, however, it is worth to remember the appearance of suspicious symptoms the fair sex.
How cancer develops?
So based on the above, the following main reasons for the development of malignant tumors of the lung:
- Inhalation of carcinogens of industrial origin from the atmosphere;
- Work in hazardous industry;
- Radioactive contamination of the environment;
- The presence of chronic diseases of the respiratory system.
Among the diseases of bronchopulmonary system is a particular danger in relation to malignant transformation pose chronic bronchitis, tuberculosis, chronic scarring, pulmonary fibrosis, purulent-destructive lesions (abscesses). Adenoma (benign tumor of the lung) can also be a source of cancer growth. Special attention should be paid to patients with pneumoconiosis, is a lung disease due to inhalation of industrial dust (asbestos, silica, coal, etc.).
Although lung cancer is usually caused by external exogenous factors, it is not necessary to forget and about possible hereditary predisposition to the tumor. The exact mechanisms and localization of genetic defects is not clear, but studies in this direction are continuing.
Noted that is more common cancer of the right lung. This is due to some anatomical features. In fact, the right main bronchus is a continuation of the trachea, while the left moves away from it at an acute angle. In such conditions a greater amount of air, and with it, harmful substances, falls into intensively ventilated lobe of the right lung, deposited there and realizing its carcinogenic effect.
Pathogenesis (mechanism of development) of lung cancer is not fully understood, but it is known that the main phases are:
When exposed to damaging factors results in irreversible changes in the genetic apparatus of cells – DNA, which is accompanied by infringement of their division, maturation and timely death (apoptosis). Hypoxia (for example, scars or septic processes), accumulation of mucus containing carcinogens, chronic inflammatory processes interfere with the normal update of the bronchial mucosa, resulting in dystrophic-degenerative and precancerous changes.
Atrophy is thinning until the complete disappearance of the mucous membrane of the respiratory tract, which disturbed the physiological process of purifying the inhaled air and are prerequisites to the development of cancer.
Multiple sclerosis is a proliferation of connective tissue in the walls of the bronchi or lung parenchyma. Causes can be chronic bronchitis, abscesses, past tuberculosis, trauma, etc. In the area of formation of a scar interferes with the normal regeneration of the epithelium and creates conditions for malignant transformation of cells.
Metaplasia from the point of view of pathomorphology represents the transition of one type of epithelium to another. So, the ciliated epithelium of the bronchi may be replaced by a stratified squamous (squamous metaplasia), which is not only able to produce mucus, enveloping the pneumatic surface and removes contaminants and dust, but also may subsequently be a source of cancer. In this regard, metaplasia, considered precancerous process mucosa.
Especially dangerous is such a process as dysplasia, characterized by disruption of the normal proliferation (reproduction) and differentiation (maturation) of cells. It can occur in foci of squamous metaplasia, atrophy, scarring. Dispostions altered areas of the mucosa have a high risk of neoplastic (neoplastic) transformation due to the fact that the cells they acquire the features of the tumor and sooner or later there is a clone, giving rise to cancer.
With the progression of these changes and the increasing severity of dysplasia, the defeat exposed the entire thickness of the mucosa lining the surface of the bronchi or bronchioles and cells acquire pronounced signs of malignancy. In such cases, indicate the presence of non-invasive cancer, not germinating deeper than the basal membrane on which the epithelium. Such a cancer has not metastasized and has a relatively favorable prognosis, but its detection is extremely difficult, so this form can only be considered a stage towards the development of invasive cancer, with all the characteristic of malignant tumors properties and complications.
Particularities of the classification and growth of lung cancer
Determination of the structure of the tumor and the nature of its growth is very important when choosing treatment and determining prognosis. The clinical picture is largely determined by how and to what Department airway is neoplasm.
In order to understand the forms of growth of lung cancer, it is necessary to recall the structure of the respiratory system:
Lungs – paired organ, each of them are located in the pleural cavity, which allows to make breathing movements and to expand the lung tissue by the flow of air. The trachea divides into right and left main bronchi with a large diameter and together with the inbound vessels respectively in the right and left lung. Each main bronchus divides into lobar, carrying air to the three lobes of the right lung and two to the left. The extent of penetration in lung tissue is reduced and the caliber of pneumatic tract. Lobar segmental bronchi give rise respectively to the segments light, then smaller down to the bronchioles. Lung tissue is represented by alveoli cells, directly where gas exchange.
Depending on the location of the tumor is isolated:
- Central lung cancer, growing from the main, lobar, or primary bronchus segmental divisions;
- The peripheral generated from the mucous membrane of distal segmental bronchus and the smaller of its branches, as well as from the epithelium of the alveoli;
- Massive cancer, or mixed, is a tumor of considerable size, affecting both large and small ramifications of the bronchial tree, with initial localization set is very problematic.
By the nature of growth relative to the bronchial wall cancer happens:
Macroscopically (depending on appearance of the tumor) lung cancer is:
- Endobronchial diffuse.
There are so-called clinical-morphological classification uniting the cancer types depending on the forms of growth and appearance. So, the Central cancer can be endo — and peribronchial (nodal and branched). Peripheral is represented by three forms: «spherical», pneumonopathy and cancer Pancoast (the top light).
There are also atypical variants:
- Primary carcinomatosis of the lung;
- The bone etc.
Besides these types of, it is also important to determine the histological structure of the tumor. The main varieties are:
Each of these kinds can have several build options depending on the appearance of cells, degree of differentiation, the ability to sliseobrazutee etc.
Often within the same tumor found cell groups belonging to different histological variants of the structure – the heterogenous structure of tumor. Since poorly differentiated tumors «survive» better, behave more aggressively and define unfavorable prognosis, the report indicates one type of structure with a higher potential of malignancy. So, if along with areas of squamous cell of the structure revealed pockets of nizkotemperaturnogo small cell lung cancer, the diagnosis is that he will appear.
The most common histological variety of lung cancer is considered squamous cell constituting more than 70% of all tumors. The source of its development are areas of squamous metaplasia of the bronchial epithelium, which often can be found in major bronchi. In this regard, it is not surprising that this cancer is usually Central. It is characterized by relatively slow growth and later metastasis in comparison with other forms.
Adenocarcinoma (glandular cancer) grows from the glandular cells of the bronchial lining often is the most peripheral lung cancer. This species is more aggressive than squamous cell variant, and despite relatively slow growth, tend to give early metastases through the blood and lymph vessels. Often adenocarcinoma growing into the pleura, causing inflammation, pleurisy, and extending across the pleural cavity with the formation of carcinomatosis (the implantation metastasis).
More rare variants (small cell lung cancer, large-cell carcinoma, bronchioloalveolar, undifferentiated forms) occur in approximately 10% of cases and their rapid growth, early and rapid metastasis and a poor prognosis.
The growth form of lung cancer is of high clinical and prognostic value. Cancer Central, produced in large bronchi, pretty early on gives clinical manifestations, because at small sizes can compromise the patency of the bronchus until it closed. Thus there is spadenie lung tissue in the area of disturbed ventilation (atelectasis), and the patient rushes to the doctor with the emergence of various symptoms.
Peripheral tumor in this respect is quite tricky: getting a large size, they may not manifest any significant symptoms, and only when the tumor invades the pleura or reaches a large bronchus, there are worrisome clinical signs. It happens that the peripheral cancer is detected at the stage of metastasis when the tumor itself is more than 5-7 cm, or even accidentally when the next x-ray examination.
Given the size of the tumor and its location, release stage lung cancer:
Classification by the TNM system allows to determine the stage of the disease in a comprehensive assessment of the tumor status of the lymph nodes and the presence or absence of distant metastases.
Metastasis of lung cancer
Lungs are organs with a very well-developed system of microcirculation and lymph flow. In such circumstances the metastasis is quite easy and is observed in more than 70% of patients.
The main route of spread of the tumor throughout the body are:
- Lymphogenic (more characteristic of Central cancer);
- Hematogenous (most often implemented with peripheral growth);
- Implantation (when the tumor ingrowth into the pleura).
Cells any cancer is poorly linked to the loss of specific cell adhesion proteins engaged in this relationship. If you have a good blood supply and lymphatic drainage they easily fall in the interstices of the vessels and migrate to other organs and tissues. So, lymphogenic metastases are found in lymph nodes – peribronchial, bifurcation (at the point of division of the trachea into the bronchi), paratracheal (in the direction of the trachea), then, upon progression, they can be found in the mediastinal lymph nodes, subclavian, cervical, etc.
Hematogenous metastasis through blood vessels occurs in the brain, bones, adrenal glands, opposite lung. Liver metastases are detected in almost half of patients.
Implant way of dissemination is more common in peripheral cancers and is in a «dispersion» of cancer cells on the surface of serous membranes – pleura, pericardium. It is possible to ingrowth of cancer in the aperture with the penetration of cells into the abdominal cavity and spreading over the surface of the peritoneum. Such processes are accompanied by secondary inflammation (pericarditis, pleurisy, peritonitis).
To a large extent to the rapid metastasis also promote regular breathing movement and intense the flow of blood and lymph from the lungs.
What is the disease?
Symptoms of lung cancer are diverse, however, clinical signs are quite nonspecific. Often tumor growth is hiding under the guise of chronic bronchitis, respiratory catarrh, etc., Many patients seek help are already in advanced stages of the disease.
When the Central cancer first signs appear early, as often happens obturation (closing) the lumen of the affected bronchus, atelectasis occurs and, as a consequence, respiratory disorders. In the case of peripheral cancer, symptoms appear when the tumor reaches a large bronchus, pleura and other entities, and the sizes of it are already significant.
The main symptoms of malignant tumors of the lung can be considered:
Such complaints makes most patients with lesions of the respiratory system, e.g. bronchitis, TB, chronic suppurative processes, etc., so often the cancer lurking under such «masks», revealed in stages III — IV.
Cough is the most common and early symptom of the disease. It is caused by irritation of receptors of the bronchial mucosa, bronchial obstruction, congestion in the bronchi of mucus or pus, often because the tumor is accompanied by a secondary inflammatory process. A cough is detected in almost all patients with cancer of the Central, while the peripheral when it can long time inexistent.
In the initial stages of development of the disease the cough is dry, painful, then there is expectoration of a different nature, possibly mixed with blood, then talking about the hemoptysis. The reasons for the allocation of blood with phlegm can be the decay (necrosis) of the tumor, the corrosion products of metabolism of blood vessel walls and damage to the bronchial mucosa. Sometimes a sputum compared to views raspberry jelly thanks to the diffuse red colouring.
Chest pain associated with tumor invasion of nerve trunks, pleura with the formation of carcinomatosis, and inflammation (pleurisy). It is also possible defeat of the ribs until foci of destruction (destruction) of bone tissue. Spadenie lung tissue and displacement of the mediastinum as the result of large tumor size accompanied by the development of pain syndrome. In some cases, at the initial stages of the disease, the pain may be mistaken for intercostal neuralgia, it is therefore important to conduct additional studies to exclude other causes of this symptom.
Shortness of breath often accompanies lung tumors and it is associated with bronchial obstruction and with the development of atelectasis. In addition, compression or displacement of the mediastinum is also accompanied by a similar respiratory disorders.
The growth of the tumor with metastasis in the nearby lymph nodes can cause a disruption of blood flow through the superior Vena cava, which is characterized by severe swelling of the face and neck, cyanosis of the skin, headaches, fainting. These symptoms characterize the tumor in advanced stages.
In the stage of metastasis, there are signs of dysfunction of those organs that have secondary tumor nodules. You may experience jaundice, metastases to liver, pain in the bones or the spine, neurological disorder caused by damage to the metastases of the brain and its membranes.
Quite early in lung cancer symptoms of intoxication. Often, they occur well before other, more typical signs of infection of the respiratory system. Characterized by a fever, sometimes up to significant numbers (in case of pneumonia in the area of cancer growth), severe weakness, dizziness, loss of body weight. Because these symptoms may be common with SARS, bronchitis, tracheitis, etc., the majority of patients using all known and available methods (antipyretics, analgesics, antibiotics, etc.) reduce their expression. The effect of this treatment in case of lung cancer is short, and the symptoms soon come back again, which pushes patients to seek help to the doctors.
With the appearance of at least part of these symptoms should not hesitate to seek assistance from specialists, as early detection of cancer gives hope for more successful treatment.
Video: symptoms lung cancer — the program «Live healthy!»
The diagnosis of lung cancer
Despite the development of modern technologies of visualization of tumors of different localization, diagnosis of lung cancer remains quite challenging. First of all we are talking about tumors of small size, do not give any symptoms. In most patients cancer is detected in advanced stages, when large amounts of tumor and even the stage of widespread metastases.
When signs of disorders in the respiratory system should consult a doctor who will examine, listen to your lungs to identify areas of lack of ventilation (atelectasis), available checking the lymph nodes and sent for further instrumental and laboratory tests.
Compulsory at the primary stage of diagnosis are clinical tests (General and biochemical analysis of blood, urine, etc.). These studies provide an opportunity to suspect a tumor growth on such grounds as increased ESR, leukocytosis (especially with accompanying inflammation), etc.
Since the initial examination and the examination of the patient fails to determine the presence of lesions of the respiratory system, there is a need for more informative methods for the differential diagnosis of cancer, chronic bronchitis, tuberculosis, lung abscess and other processes.
The primary method to determine the presence of cancer is x-ray. Review of the chest radiograph in different projections provide an opportunity to establish the localization of the growth of a tumor node, to detect the presence of fluid in the pleural cavity.
When the Central cancer on the radiograph you can see parts of CHS (atelectasis) in the form of blackouts, the relevant Department of the lung, which is not supplied with air through Abdulrahmanly (indoors) bronchus. Peripheral tumors can be detected in the form of so-called «round shadows». With the involvement in the process of lymphatic and blood vessels can be seen «track» to the root of the lung as a line of enlightenment, «stretching» of the tumor in the direction of the mediastinum.
Version of the x-ray light is fluoroscopy. This method is simple to perform, cheap and allow to cover the General population, therefore screening to detect tuberculosis and other lung diseases.
Fluoroscopy helps diagnose also cancer, but more often it occurs with a significant size of the tumors, it is therefore advisable, in addition to comprehensive, conduct targeted surveys of individuals with an increased risk of cancer (smokers, patients with chronic nonspecific lung disease, the presence of occupational diseases – pneumoconiosis, etc.). This approach will allow to increase the percentage of detected tumors at an earlier stage of development.
In some cases, resorted to computed tomography, allowing to carry out x-ray examination in a certain plane, to image lymph nodes affected by metastases, etc. can be Informative also conducting MSCT and MRI.
In addition to radiographic methods, very important and of great diagnostic value has the performance of bronchoscopy. Using a special endoscopic camera, the doctor is able to examine the surface of the bronchus from the inside, to determine the location and type of tumor growth, but also to take her fragment for subsequent histological studies, which will also help to determine further treatment tactics and a list of required procedures.
Bronchoscopy allows you to make an accurate diagnosis in almost 100% of cases Central to cancer however, in peripheral tumors can be some difficulties, and therefore apply the so-called transthoracic needle biopsy with a thin needle under x-ray, after which, fragments of tumor tissue are sent for cytological and histological examination. This method requires great precision and skill of the doctor as fraught with various complications of the abuse of its implementation.
Patients with Central cancer of some value may have sputum Cytology, which can be detected by cancer cells, however, approximately 30% of cases the method does not give any results, therefore, cannot be an independent study and is carried out only in combination with other treatments.
Morphological (cytological and histological) study of the fragments of tumor tissue allows to determine its structure, the degree of differentiation and the type that not only has great prognostic value, but also determines the effectiveness of therapy, given the sensitivity of this type of cancer to various influences.
In difficult cases, when the described methods do not allow accurate diagnosis, resort to thoracoscopy that allows you to inspect the pleural cavity and biopsy of the tumor sites. This method will be informative in that case, if the tumor has invaded the pleura, and therefore more suitable for peripheral cancers or massive growth forms.
Thoracotomy is the final diagnostic step, which is a surgical intervention, therefore, is only the ineffectiveness of other methods of cancer detection.
When individual histological types of cancer examination could have some variation. So, when small cell variety is necessary examination of the brain (CT, MRI), and bone (bone scan) to exclude the presence of early hematogenous metastases. In addition, we investigated cervical lymph nodes and bone marrow. The data obtained are reflected in the determination of the stage of the tumor according to the TNM system, and further, based on this, you will select a particular treatment strategy.
Successful diagnosis is the key to effective therapy
So, diagnosed, many difficult, unpleasant and painful procedure behind. There comes a stage in the treatment of lung cancer when co-developed tactics of doctors, radiologists, pulmonologists and oncologists determine the effectiveness of therapy, the duration and quality of life of the patient.
Cancer detection the small size and the absence of metastases can achieve a high survival rate of patients. In most cases, used a combination of surgery, radiation and chemotherapy.
Resection of the tumor within healthy tissues is radical and most effective way of dealing with the disease. This removes also lymph nodes which can become subsequently a place of growth of metastases, and fiber mediastinum. In case of large tumor size, involvement of surrounding organs and tissues, the presence of metastases surgical treatment may be technically feasible and dangerous in terms of complications. In such cases, limited to the purpose of the chemotherapy and radiation treatment.
Surgical treatments may be radical and palliative. The latter involves leaving part of the tumor tissue, the affected lymph nodes when there is a risk of bleeding from the tumor and other threatening complications. In addition, some of the patients are old and have some form of CHD, arterial hypertension and other diseases which complicates surgical intervention and anesthesia.
Radiation therapy can be as an independent therapeutic method, and as a part of complex treatment. The mode, dosage and duration of the exposure picks up the radiologist based on the prevalence, differentiation grade and histological variant of the tumor. This method has only local impact, therefore, leads to the destruction of the tumor tissue, but not prevent its spread and circulation of cancer cells through the blood and lymph, and in this connection it should be supplemented by chemotherapy.
Chemotherapy has no independent value in the treatment of lung cancer, but in combination with other methods leads to an increase in life expectancy of patients and improve their overall health. Anticancer drugs are more sensitive small cell lung cancer and in most cases, with it even possible to achieve a full remission, so you can live longer but after a while the inevitable relapse and progression of the disease.
Thus, only a comprehensive approach in the development of tactics of treatment for a particular patient may give a positive result.
Despite the development of medicine in General and Oncology in particular, folk remedies for the treatment does not lose its popularity among the population. Unfortunately, a large number of people believe in the miracles of healing by traditional methods, losing precious time and postponing the visit to a specialist. Carried away by such means, the sick reach the doctor in advanced stages of the disease, and sometimes not fall at all due to progression of the tumor and death.
The Internet is abundant with information and the different sites according to folk remedies, however, be aware that the information was provided very often by people without medical education and views about the nature of tumor growth. We must be very careful, taking note of any specific recipes.
Of course, no harm from inhalation of propolis, apply calendula and chamomile, which has anti-inflammatory effect, however, any such tool should be consumed ONLY after consulting a doctor and ONLY on the background of traditional treatment. In the case of lung cancer miracles do not happen, and cure grass plantain or infusion of the mushroom can not be achieved, so you need to be vigilant and to trust, first of all, experts in the field of Oncology.
The prognosis of lung cancer remains serious. If untreated, patients do not live more than two years, and when nizkoeffektivnyj tumors even during therapy, life expectancy is often no more than a year. Early detection, comprehensive approach to non-small cell lung cancers can achieve a survival of about 80% of patients in the first stage of the disease, survives only in the second half of patients.
For the prevention of lung cancer, it is important to withdraw from active Smoking avoid passive inhalation of tobacco smoke, use of PPE when working in hazardous occupations. It is impossible to ignore the annual chest x-rays, and when the complaints should go to the doctor.
In institutions of education and health need to conduct extensive sanitary-educational work with the population to explain the negative influence of harmful habits on human health. To combat dust and radon need to have frequent wet cleaning and airing.
Medical institutions for cancer, in turn, are also active in prevention, promote early detection and effective treatment of malignant tumors.
Healthy lifestyle, physical activity, proper nutrition – the key to successful cancer prevention and well-being in General.