This is, to a certain degree, accounted for by the causative factors, the principal ones of which are: smoking, jagged teeth, the scars of syphilis, alcoholic drinks, the pressure of a pipe-stem on one spot, a traumatism; various orders of the tongue, especially leuko plakia, etc.; in fact, any condition which tends to cause irritation of any one part of the organ. A condition of the sur face of the tongue called "leucoma" by Hutchinson, a form of chronic glossitis, appears as a primary cause in 16 out of 80 cases analyzed by Butlin. The promiscuous application of solid nitrate of silver or any kind of caustic is also thought to be another prolific source.
The age at which epithelioma of the tongue appears corresponds to that of cancer in other parts of the organism, namely: after 45 years. Occasionally, however, it occurs earlier. According to Warrington Howard (Lancet, Mar. 2, '95), a larger proportion of the cases found to be under 30 occur in women.
Hereditary predisposition may be traced in many cases.
Prognosis.—Left to itself, lingual epi thelioma steadily progresses, and death occurs in from eighteen months to two years after the character of the neoplasm has been recognized. In a series of 69 cases treated by Sachs the average time elapsed between the onset of the growth and the time the cases presented selves for treatment was five months. It is probable, therefore, that two years represent the average duration of life from the start of the initial lesion. The prognosis is also greatly influenced by the thoroughness of the operation formed; the more radical this is, the better are the chances, especially if boring glands are involved. An early involvement of the glands is an able sign, particularly when the cervical glands behind the angle of the jaw are affected. An operation, if performed when the case is not too far advanced, invariably prolongs life even in cases of recurrence. This is especially evident in private eases.
Study of 102 eases of operation for cancer of the tongue in which primary operation was performed. Nearly an equal number was operated upon in hos pital and private practice. After getting returns from all hut 7 eases, it was found that, besides the fact that the mor tality was greater immediately subse quent to the operation in the hospital cases, the number of absolute cures with freedom from return, in some cases for thirteen years, and in all for over three years, was much greater in the private than in the hospital cases. Number of deaths due to operation in hospital group is 9, while only I of private patients in whom there was marked involvement lost. Number of such patients alive and free from disease more than three years after operation, or who died from other causes after the extirpation of three years. was 7 in hospital group and 13 in
other group, and there are 9 others free from return after one year, but not over three years, while there are only 2 hos pital patients who may prove cures. Percentage of cures in hospital group of cases at best is 16, while private cases is 26, with a chance of its being much greater.
The reason for the difference in results is that the private patients are better educated and come for operation much earlier than do the others, which illus trates great advantage for early opera tion. Cases which may be claimed as cured show that the disease, in the large majority of them, was situated in the anterior two-thirds of the tongue. But even some of the worst eases may be cured if the disease has not invaded the tonsillar and neighboring regions. Among private patients cured there was not one in whom the glands were re moved, while, in the hospital cases, of the 7, 5 had the glands removed at the time of the operation or immediately subsequent to it by a second operation, and in 4 or 5 they were not only en larged, but proved by microscopical ex amination to be cavernous. The whole tongue was removed in only 1 of the suc cessful cases. Butlin (Brit. Med. Jour., Feb. 26, '9S).
Treatment. —According to Butlin, whose results have been, when compared with those of many other operators, most satisfactory, removal of the entire tongue is not essential to a successful operation. With the cancer, he removes three fourths of an inch of apparently healthy tissue around it in every direction.
When the disease is on the border of the tongue, half the tongue to an inch hind the margin of the disease, is ex sected. In cases in which the disease is near the tip or forepart of the dorsum, the forepart of the tongue is removed.
During recent years this surgeon has resorted to the following operation, in which the entire contents of anterior triangle of the neck is removed: A very careful dissection of the triangle is made, so that the connective tissue and glands are all taken out in one continuous mass. Search is made be tween the muscles in front for one or two deeper-seated lymphatic glands, and the glands in front of the parotid gland and about the angle of the jaw are taken out with the contents of the triangle. The submental and parotid glands are not so easily and certainly removed en masse in this operation as the submaxil lary and carotid groups. This is done at a second operation, and not at the time of the excision of the tongue.