Preliminary report on the influence of lecithin and cholesterin upon the growth of tumors

Abstract

Sixty-one white rats, obtained from local sources and hereafter designated “Local” were inoculated in the axillary region with portions of a Flexner-Jobling carcinoma which was obtained from the Rockefeller Institute for Medical Research through the kindness of Dr. Peyton Rous. The number of successful inoculations, determined after 19 days, was 42, or 69 per cent.

Sixty-four rats obtained from dealers in Chicago and hereafter designated “Chicago” were similarly inoculated with portions of a Flexner-Jobling carcinoma which had been obtained from the Rockefeller Institute for Medical Research early in the year and propagated through four generations of rats in this laboratory. The number of successful inoculations, determined after 18 days, was 55, or 86 per cent.

Both sets of tumors grew rapidly, attaining average diameters of 15.0 and 11.9 millimeters after 19 and 18 days respectively.

Beginning upon the 19th day in the case of the “Local” and upon the 18th day in the case of the “Chicago” animals, each of the two groups of animals was sorted without selection into three batches, of which one (consisting of 12 animals in each case) served as controls, another (10 “Local” and 13 “Chicago”) received 1 c.c. of a 3.9 per cent. suspension of cholesterin in N/10 sodium oleate solution, which was injected hypodermically directly into the tumors every 2d or 3d day (three times a week); the third batch (20 “Local” and 30 “Chicago”) received 1 c.c. of a 2 per cent. aqueous emulsion of lecithin similarly injected into the tumors upon the same days.

It was found that in the pre-metastatic stage cholesterin causes a very notable acceleration of the primary growth, the gain in diameter between the 19th (18th) and 24th (23d) days being 11.6 mm. in the “Local” and I 1.4 mm. in the “Chicago” animals as compared with 4.8 mm. and 2.9 mm. respectively in the controls.