The cancer of a lung, as well as in general cancer of any localization, does not arise on healthy ground. It is preceded with the long pathological processes caused that or other etiological factor. Last, influencing systemic and topical of a mucous membrane, causes chronic inflammatory process which under influence of a proceeding long irritation can lead to cancer transformation. For an explanation of accruing frequency of a cancer of a lung many theories were offered.
From the conditions favorable development of a cancer of a lung, it is impossible to exclude an exhaustion and the overstrain of the central nervous system breaking its adjusting influence. On this background cancerogenic substances render more powerful influence on a mucous membrane of respiratory ways and chronic proliferative processes turn in cancer more quickly.
As a etiological factor in development of a cancer of the lung, influencing increase in its frequency, especially among men, smoking is important. Experimental, clinical and statistical works of last years have convincingly proved a role of a tobacco smoke in development of a cancer of a lung. Alongside with local cancerogenic influence of tobacco tar on a mucous membrane of respiratory ways the general influence of this poison on an organism which reduces its resistibility in relation to various harmful agents here matters. The long and persistent irritation of a mucous membrane tobacco tar often leads to cancer transformation of cells of a mucous membrane of bronchial tubes.
For last years attention of researchers all involves a question on influence of smoking of tobacco on development of a cancer of a lung more. A plenty of experimental, clinical and statistical works is devoted to this question.
A lot of clinical and statistical works also confirm value of smoking of tobacco as important etiological factor in development of a cancer of a lung, thus the great value has smoking cigarettes. It proves that at smoking cigars smoking inhales a tobacco smoke less, and lets out it from a mouth while at smoking a cigarette smoking inhale all smoke more and thus influence a tobacco smoke all respiratory device and first of all mucous membranes of a bronchial tree. This position is supported with statistical data who show, that the cancer of a lung meets at smoking cigarettes, than at smoking cigars while the cancer of an oral cavity meets at smoking cigars is more often is much more often.
Summing up to judgments concerning etiology of a cancer of a lung, it is necessary to tell, that is available three basic factors, leading its occurrence, that set and interaction of these three major etiological factors can, as it seems to us, to explain accruing frequency of a cancer of a lung. All from this three etiological factors solving, apparently, is a tobacco smoke.
