Cancer of the breast is usually spheroidal cell carcinoma but the columnar cell type also occurs notably in so-called "duct car cinoma" which is a less malignant variety. Sarcoma is also met with. Carcinoma is either hard and fibrolic (scirrhus) or highly cellular (encephaloid) but many intermediate forms occur even in different parts of the same breast. A scirrhous growth is rela tively smaller and runs, locally, a less rapid and extensive course than encephaloid, but as regards extension from the primary focus and the occurrence of secondary growths there is little difference between them. Sarcoma of the breast locally forms a large growth and the secondary growths have a somewhat different distribution. Speaking generally, scirrhus is associated with an atrophied and shrivelled breast and retraction of the nipple.
It is often said that cancer runs a more rapid course in the young; statistical evidence does not support this view, though many cases in the very aged progress but slowly. On the other hand during pregnancy a cancer of the breast participates in the rapid growth of the organ. But there is no evidence that suckling conduces to cancer; on the contrary, abeyance of the natural function seems to be related to the occurrence of chronic mastitis and consequently to local cancer after a longer or shorter interval. The treatment of cancer of the breast depends to an over whelming extent upon the earliness with which the disease comes under full and proper treatment. If cancer of the breast is dealt with by the modern complete operation while the growth has not extended beyond the limits of the organ some go% of the patients are alive and well ten years later and their expectation of life is not materially different from that of women of the same age who have not suffered from cancer. But if the cancer has extended
beyond the limits of the gland, a matter of a few weeks from the time when it first becomes recognizable, the case is very different. For in spite of the same operative treatment go% of the patients will be dead by the end of ten years. No better evidence could be given for the paramount value of early and adequate operation, but the surgeon is dependent upon the patient and there is evi dence that about half the number of patients dying with cancer of the breast do not seek medical treatment at all till the last days of life and of the remainder who seek advice an average period of six months or more has elapsed between their first noticing that something was wrong and consulting a surgeon. There may be many explanations of this delay but the fact remains that with each hour they have been throwing away a good chance of healthy life. In cancer of the breast early and complete operation easily holds the first place for success so far as our present knowledge goes. Radium and X-ray treatment, though highly valuable in some other sites, are far inferior to surgery as curative agents in cancer of the breast with the present technique. Possibly it will remain so even with improved technique because of the special peculiarities appertaining to cancer of this organ. Upon this point no confident opinion can be given. When the disease is beyond operative treatment, radiation methods may nevertheless afford relief.
For bibliography, see CANCER CANCER RESEARCH.