Lung cancer occupies a leading position among all malignant tumors in terms of mortality. Due to the nonspecificity of manifestations and a long asymptomatic period, early diagnosis of the disease is a serious problem and is one of the most important tasks of modern oncology.
Stages and periods of development of the disease
The prevalence of lung cancer is estimated using the TNM system, according to which there are 4 stages of the process. So, a malignant lung tumor of stage IA is characterized by its small size (up to 3 cm) and the absence of secondary foci. While stage IV corresponds to the formation of any size, which has at least one distant metastasis.
In the clinical course of lung cancer, the following periods are distinguished:
- Biological – a time period that begins from the moment the first atypical cells are formed and ends with the appearance of radiological symptoms.
- Preclinical (asymptomatic). A neoplasm in the lungs can be detected by x-rays or bronchoscopy.
- Clinical, in which subjective symptoms appear.
- Stage I lung cancer most often corresponds to the biological or preclinical period. Due to the fact that there are no signs of the disease, the patient does not have a reason to consult a doctor. The overwhelming majority of patients notice changes in the state of health only at stages II-III, however, at this time, the nonspecific nature of the symptoms is noted.
Signs suggestive of lung cancer
All symptoms that can be found in lung cancer are divided into 3 large groups:
- Local (primary), the appearance of which is directly caused by the tumor. These include: cough, shortness of breath, hemoptysis, chest pain.
- Secondary manifestations are observed as a result of the formation of regional and distant metastases (and / or when a tumor grows into the nearest organs), as well as in a complicated course of the disease.
- General symptoms: weight loss, weakness, fatigue, fever. These signs may be a manifestation of the toxic effect of a tumor on the body or may result from the addition of an inflammatory process.
- Also, lung cancer can proceed under various “masks”. That is, the patient is diagnosed, based on the presence of typical symptoms, other pulmonary pathologies: bronchiectasis, focal pneumosclerosis, pleurisy, pneumonia, etc. In this case, the root cause of these diseases is the growth of a malignant tumor in the lung.