Fluctuations in the Growth Energy of Malignant Tumors in Man, with Especial Reference to Spontaneous Recession

Abstract

It is a generally accepted fact that transplanted animal tumors may fluctuate widely in their growth energy, the fluctuations varying from a temporary cessation of growth followed by renewed cellular activity to recession and complete disappearance of the tumor. Hence, warning has repeatedly been given against drawing deductions from the results of experimental therapeutic procedures in animals without proper consideration of these natural changes in the growth energy of tumors. Though this is not widely known, the warning is applicable also to the spontaneous tumors of man, since fluctuations of a similar character are a not uncommon occurrence in them, as the reviews of this subject by Lomer, Mohr, Gaylord and Clowes, and others, amply demonstrate. Handley has well expressed the situation as follows: The progress of a cancer is normally accompanied by regressive or curative processes. The recorded cases of natural repair of cancer, far from being anomalous and exceptional, merely illustrate more strikingly than usual the natural laws which govern every case of the disease. Indeed, the literature of cancer is rich in reports of the recession of malignant tumors after one or another type of medical treatment, the particular therapeutic procedure which is supposed to have brought about the recession in each case being at once hailed as a “cure,” only to give rise to failure and disappointment when tried out on a large group of cases. It is probable, therefore, that the isolated cases referred to are really spontaneous recessions and not therapeutic cures.