Malignant neoplasms of the respiratory system are the most common oncological pathologies. The first place among them is lung cancer, annually there are more than 1 million such diagnoses. Because of the rapid progression and complexities of treatment, the tumor belongs to the group of most dangerous malignant diseases.
Causes of lung cancer
This pathology arises from cumulative changes in the structure of the DNA of the bronchial epithelium. The more tissues are damaged, the higher the risk of tumor formation. The main causes of lung cancer are carcinogens, especially if they enter the body regularly. Toxins gradually change the genetic structure of the epithelium lining the bronchi. Other factors provoking the disease include viral infections and radioactive (ionizing) radiation.
The main cause of lung cancer
Almost 90% of all cases of the disease in question and its symptoms debut due to smoking . This bad habit increases the risk of malignant growth by a factor of 20. Not only nicotine, suppressing immunity, provokes lung cancer - the causes of the tumor are hidden in the action of carcinogens, including the radioactive isotopes of radon present in tobacco smoke. In addition to the known toxins, it contains more than 4000 unrecognized chemical compounds.
Causes of lung cancer in non-smokers
Symptoms and signs of the described disease are found in people without addictions, but rarely (10-15% of cases). While there is no conclusive evidence that passive smoking is the cause of lung cancer, it is among the circumstances that have the formation of tumors in the respiratory system. Less common factors provoking the pathology in question:
- dust;
- asbestos;
- radon;
- some types of viruses;
- arsenic;
- nickel;
- chromium;
- cadmium;
- radioactive irradiation;
- chronic bronchial pathology.
Lung cancer is a psychological cause
Most specialists are inclined to believe that the presented oncological disease is multifactorial, and it is caused by a combination of adverse effects on the body. Some researchers identify additional psychosomatic causes of lung cancer:
- inability to create a strong family;
- disappointment in life;
- bad relations with parents;
- absence of close friends or emotional attachments;
- impossibility to realize their own potential.
The listed problems only theoretically have to the appearance of symptoms and signs accompanying malignant neoplasms in the respiratory system. There are no official medical studies confirming the role of such factors in the occurrence or progression of cancer. In connection with the lack of evidence of this theory, oncologists rarely pay attention to the psychological causes of pathology.
Types of lung cancer
There are several variants of classification of the described disease. In domestic medicine, it is customary to differentiate according to the 2 criteria - the histological characteristics of tumor cells and the severity of symptoms and signs in accordance with the stage of development. It is important to determine the type of the disease right away, different forms of oncological neoplasms have their own rate of progression and require special treatment.
Types of lung cancer by histology:
- small-celled;
- non-small cell.
Types of tumors by severity and severity of symptoms:
- Stage 1 - mild, early;
- 2 stage - moderate, medium;
- Stage 3 - severe;
- Stage 4 - very heavy, inoperable.
Small cell lung cancer
Rare (occurs in about 20% of cases), but an aggressive and rapidly spreading form of the disease, its symptoms are diagnosed primarily in smokers. Understand what is small cell lung cancer, helps to study the tissues that make up the tumor. It is formed from small structures that freely penetrate into the bloodstream and the lymphatic system due to microscopic dimensions. Pathological cells are easily built into healthy organs, leading to the appearance and growth of metastases.
This is the most dangerous and insidious lung cancer - the symptoms and signs of a small-cell type of disease have not been observed for a long time. A person does not know about the presence of a problem until he begins to cough up blood and feel the consequences of growth of the neoplasm. Due to the lack of clinical manifestations, this type of disease is often diagnosed at a late stage of development.
Subtypes of small cell tumors:
- pleomorphic;
- oat cell;
- spindle cell.
Non-small cell lung cancer
According to the name, the type of neoplasms under consideration consists of large organic structures. This form of the disease is more common, its symptoms are diagnosed in about 80% of cases (slightly more). Presented tumors grow more slowly and rarely cause the appearance of metastases, but their danger and harmful effects on the body systems are similar to the previous type of pathology.
The most common non-small cell lung cancers are adenocarcinoma and epidermoid (squamous, squamous-cell) carcinoma. Other, less frequent, variants of neoplasms:
- bright cell;
- giant cell.
Signs of lung cancer
The clinical picture of the disease depends on the stage of its progression and severity, the presence and number of metastases. Of great importance is the place where lung cancer develops - the symptoms and signs of the central tumor (from the mucous membrane of the large bronchus) are more pronounced and manifest at an early stage. As it grows, it affects numerous nerve endings and irritates surrounding tissues, so a person notices changes in the functioning of the body.
At first, there are no external signs of lung cancer when there is a neoplasm in the peripheral parts of the respiratory system. In the tissues of the branches of the bronchi there are no painful receptors and nerve endings, so the brain does not react to the growth of the foreign structure. Specific symptoms appear only in the late stages of disease progression.
Lung cancer - stage 1
The described form of pathology proceeds without clinical manifestations. Neoplasm is still too small, no metastasis, so the first signs of lung cancer are absent. The diameter of the tumor reaches a maximum of 3 cm, it is located within a single pulmonary segment. Sometimes the accumulation of mutated cells is localized in a small bronchial branch. It is extremely rare to diagnose such lung cancer: the symptoms and signs in the early stages are so worn out (or they are not) that patients do not seek help. The tumor is detected accidentally on a routine examination.
Lung Cancer - Stage 2
At this stage, the size of the neoplasm increases to 5-6 cm (maximum diameter). It still does not expand much, but it allows single metastases, so there may be early signs of lung cancer at an early stage:
- fatigue;
- apathy;
- low working capacity;
- drowsiness, lethargy.
These symptoms are not associated with the presence of a malignant tumor, they are inherent in a variety of diseases. Signs of lung cancer in women and men are the same, the diagnosis is identical. Later, there are other clinical manifestations, also nonspecific:
- uncaused loss of body weight ;
- increase in temperature to 37 degrees;
- sleep disorders.
Lung Cancer - Stage 3
At the described stage, malignant neoplasm has large dimensions, more than 6 cm in diameter. There is a typical clinical picture, so the patient turns to the doctor or does x-ray - signs of lung cancer are already specific:
- dry, often recurrent cough;
- dyspnea;
- susceptibility to pneumonia without an infectious agent;
- soreness in the chest;
- increased body temperature;
- low weight.
During the examination, there are metastases that start lung cancer - symptoms and signs of pathology include the defeat (enlargement, inflammation) of several groups of lymph nodes:
- tracheobronchial;
- bifurcation;
- paratracheal;
- bronchopulmonary.
Lung Cancer - Stage 4
A severe variant of the course of the disease is accompanied by a rapid growth of the tumor, often it extends beyond the initial segment and penetrates into neighboring organic structures. In such cases, lung cancer is almost immediately confirmed - symptoms and signs of stage 4 include all of the above clinical manifestations, but more pronounced:
- hoarseness of voice;
- purulent sputum, which is released during coughing;
- lack of appetite;
- paralysis of the diaphragm;
- pain in the region of the heart;
- puffiness of the face;
- skin is bluish-violet in color (cyanotic);
- swollen veins on the neck and arms;
- dermatitis;
- change the shape of the fingers ("drumsticks").
During a cough, red sputum is often coughing up, which is a blood clot. Due to damage to the respiratory system, a person suffers from accompanying ailments:
- pericarditis ;
- chronic obstruction;
- pleurisy ;
- pneumonia.
Less often during differential diagnosis, lung cancer is detected - late symptoms and signs of a tumor include numerous local and distant metastases. They germinate not only in the lymph nodes, but also into internal organs, provoking acute violations of their functions. Metastases are more prone to:
- kidney;
- bones;
- adrenal glands;
- brain;
- liver;
- a heart;
- esophagus;
- trachea;
- any nerve nodes;
- thymus.
Lung cancer - prognosis
While it was not possible to develop an effective algorithm of therapy, which allows to cure pathology. You can not completely eliminate lung cancer - the symptoms and signs progress, the tumor grows and gives metastases. The earlier the disease is identified, the higher the chances of improving the patient's condition. If the diagnosis is made in the first stage, the 5-year survival rate is about 60%, the second - about 40%, the third - up to 15%. Severe oncological disease leads to death within 12-24 months. A similar result, if you do not treat lung cancer - the survival forecast does not exceed 1-2 years.