Nutritional manipulations and tumor growth. I. The effects of starvation.

The effects of starvation on tumor and host growth were studied in growing male Fischer rats bearing methylcholanthrene-induced sarcomas. Tumor growth was evaluated by changes in weight, volume, and incorporation of tritiated methyl thymidine into tumor DNA, (dpm/microgram DNA). Host growth was followed by changes in total body weight, carcass weight, and dpm/microgram liver DNA. All periods of starvation (24 to 96 hr) caused significant decreases in host body and carcass weight and dpm/microgram liver DNA. Changes in tumor weight and tumor volume in fed and starved animals were equal. Tumor dpm/microgram DNA in starved animals increased (P less than 0.005) relative to fed controls at 48, 72, and 96 hr starvation intervals. Starvation allows continued tumor growth while host wasting occurs, and is accompanied by increased tumor dpm/microgram DNA in this system.