carcinostatic

adjective

car·​ci·​no·​stat·​ic ˌkär-sə-nō-ˈsta-tik 

: capable of inhibiting the growth of malignant tumors

Standardized beta-glucan extracts … show particular potential as carcinostatic agents that can be used in conjunction with conventional medical treatments to treat cancer.

—Mark Mayell, Alternative Medicine Review