Further Notes on the Relation of Nutrition to the Development of Cancer.

Abstract

In previous papers 1 we had shown that malignant tissue differs from the normal tissues of the body in that it contains no demonstrable or very little of the growth promoting fat soluble vitamins. We had also shown that many of the so-called cancer producing substances and forces, such as coal tar, other lipoid solvents, x-rays, radium, other lights and heat act directly to dissolve or otherwise remove these fat soluble vitamins from the tissues. While these studies were interesting in that they indicated that cancer may be nothing more than the result of the removal of the fat soluble vitamins from a tissue, it seemed quite unlikely that a lipoid solvent, no matter how often applied to a tissue, could remove sufficient of the vitamin to induce cancer. When a solvent is brought into contact with a medium it removes only a certain fraction of the dissolved substances from the medium.

That the local action of coal tar is not alone responsible for coal tar cancer has been indicated further by the fact that all animals painted with coal tar do not develop the disease while cancers have been known to develop in man years after a single injection of paraffin or a single dose of x-rays. There seems also to be little evidence to show that the appearance of cancer in man is related directly to the extent or severity of a previously existing local lesion. In fact, many patients carry definite precancerous lesions for years without any evidence of malignant degeneration. All these facts indicate, therefore, that factors other than the local lesion must be responsible for the malignant changes. To throw light on the possible nature of these other factors it has become of interest to study more carefully the action of coal tar and x-rays on animals fed a normal dietary and animals fed varying quantities of both vitamin B and the fat soluble vitamins.