Lung cancer is the most common cancer in men. It causes most deaths in Europe and America. Lung cancer morbidity is directly proportional to tobacco smoking. Due to asymptotic disease course, lung cancer is usually diagnosed too late, therefore, the treatment is extremely difficult and the prognosis is bad.
Causes
The main cause is tobacco smoking. The risk of lung cancer is highly related to the amount of cigarettes smoked during lifetime. Even passive smoking might double the risk. 95% of lung cancer cases are related to continuing smoking (including light cigarettes and pipes). Other cases are correlated to asbestos, chrome, genetic factors and air pollution.
Similar to other cancers, lung cancer consists of uncontrolled cell growth as a result of long-term contact to carcinogens, mentioned above. Damaged genes of a lung cell start uncontrolled cell growth. These cells form a tumor, infiltrate surrounding tissues, reach blood and lymphatic vessels and start metastasizing. The tumor disrupts the metabolic balance and consumes nutrients in the organism.
Symptoms
During the first stages, lung cancer is asymptotic. Later the symptoms depend on the localization of the tumor. Lung cancer might cause shortage of breath, coughing chest pain (rarely), pleuritis (pleurisy). Symptoms also depend on the metastasizing of lung cancer. Metastasizing to the mediastinum might cause hoarse voice, facial edema. Metastasizing to the central nervous system usually causes neurological symptoms, metastasizing to the bones causes severe pain etc. Advanced lung cancer often causes paraneoplastic syndrome (skin rash, hypotension, weight loss, etc.).
Diagnostics
Lung cancer is often detected accidentally by performing chest radiography. Otherwise, this test might be false negative. CT is much more informative and precise. If the tumor is endobronchial, bronchoscopy is usually performed. The diagnosis is verified with a biopsy (endobronchial, transbronchial or transcutaneous).
According to the results of biopsy and other tests, the tumor is classified (Non-small Cell Lung Carcinoma and Small Cell Lung Carcinoma) and staged (from IA to IV).
Treatment
The method of treatment depend on cancer’s cell type and stage. During stage I to II (sometimes in stage III) the main method of treatment is surgery. During stage III – IV chemotherapy and radiotherapy are performed. Symptomatic treatment is also essential.
Prognosis
Prognosis of lung cancer depends on cancer’s type and how far it has spread. Non-small Cell Lung Carcinoma usually has a better prognosis than Small Cell Lung Carcinoma.