CANCER, a disease characterized by slow alterations of structure, or tumors in vari ous parts of the body, occurring either simultaneously or in a certain order of succes sion. In many cases, an isolated tumor in an external part is the earliest symptom; it is then viewed at the starting-point of the disease, and is termed a malignant tumor (tumor 'mall moris), from its presumed tendency to infect the system, and to cause the reproduction of growths similar to itself. It is right, however, to remark, that upon the pathology of C. authorities are by no means agreed, some holding that a constitu tional taint or diathesis must always precede any local development of C., and that the first growth in point of time (or primary C.) is therefore only the first of a series deter mined by a pre-existing cause in the blood or general system; while others hold that C. is originally a truly local disease, or even that a growth at first simple or benign), may, in consequence of local causes, e., become cancerous, and infect the whole system with the morbid tendency thus secondarily acquired. The dis cussion of this disputed question involves statements of a too complicated kind to be in place here: but it is a question of considerable importance, as bearing on the probability or improbability of curing the disease by extirpating the primary tumor at an early stage of its development. All authorities are agreed that, when any trace of secondary C. exists, the removal of the parts affected gives scarcely any hope of a favorable result, and, accordingly, operations under these circumstances, unless merely for the relief of local suffering, are discountenanced by all respectable surgeons. The disease, however, is one of which the ignorant as well as the learned have a well-founded dread, and hence it presents a large field for the practice of imposture, and for that less deliberate, but often not less hurtful kind of quackery which is the result of pure ignorance, grafted on a meddlesome desire to do good. \Ve propose to give such a sketch of the characters and progress of cancerous disease as may serve, in some degree, as it protection against ignorance on the one hand, and deception on the other.
The leading character of C. being a tumor or morbid growth in a part, it is import ant, in the first place, to observe that not all, nor even the majority, of morbid growths are cancerous. A very large proportion of growths, involving swelling or change of structure in a part, are either determined by a previous process of inflammation—leading to chronic abscess and induration—or belong to what is called the non-malignant order of tumors—e. g., cysts, fatty and fibrous tumors, simple hypertrophy of glandular struc tures, cartilaginous, bony, calcareous, and vascular growths. See Tumous. Further, among the tumors admitted by general consent into the order of cancerous, there are widely different degrees of malignancy or cancerousness, so to speak; some having the tendency to spread rapidly, and infect the system at an early period, while others remain local for a considerable time, and may be removed while yet local, with good hope of a permanent recovery.
Now, the practical distinction, or diagnosis, to use the technical phrase, of these dif ferent tumors, is founded upon a very careful and delicate appreciation of the characters of the malignant and non-malsgnant tumors, considered as morbid products, and also upon a thorough knowledge of the anatomy and relations of the textures in which they arise. One of the leading characters of malignant tumors is the tendency to involve, by a kind of specific destruction or degeneration, the ultimate elements of the textures in which they arise and in which they spread. The attempt, therefore, to distinguish these from other growths, must always call for the highest qualities of the surgeon—large experience, guided at every step by consummate science, and, in particular, by minute and thorough knowledge of natural structure. And the difficulties of the inquiry are such, that even in the (lead body, or in a tumor excised from the living body. all the resources of the anatomist, aided by the microscope, will occasionally fail in distinctly and surely discovering the true character of the morbid structure.