The components of a brew/extract of leaves or other parts of the papaya plant (Carica papaya) or fractionated components thereof are effective in the prevention or treatment of stomach cancer, lung cancer, pancreatic cancer, colon cancer or other solid cancers, or lymphoma, leukemia or other blood cancers, and are very safe with few side effects, making their medical significance extremely high. In addition, food compositions comprising a papaya plant (Carica papaya) extract component as an effective ingredient for the prevention or amelioration of cancer are highly expected to become functional foods contributing to the preservation and promotion of human health.