A Japanese study led by Upadhyaya demonstrated that beta-carotene does-dependently induced apoptosis and cell differentiation in cultured leukemia cells but not in normal cells. Microscopic observation revealed that beta-carotene formed apoptotic bodies in the leukemia cells . Beta-carotene could reduce damage caused radiation therapy and decrease local cancer recurrence. Meyer and coworkers conducted a study on 540 cancer patients who were treated with radiation therapy. They found that dietary intake of the antioxidants beta-carotene result in fewer adverse effects and a lower risk of cancer recurrence. The intake of vitamin E had no such effects .
Angiogenesis is a physiological process involving the growth of new blood vessels from pre-existing vessels and is a fundamental step in the transition of tumors from a dormant state to a malignant state.
An Indian study, involving in-vivo and in-vitro experiments, found that beta-carotene inhibited angiogenesis by altering the cytokine profile and could inhibit the activation and nuclear translocation of transcription factors. The in-vivo experiment with mice showed that beta-carotene significantly reduced the number of tumor-directed capillaries and changed serum cytokine levels. The in-vitro experiment, which involved aortic ring assay, endothelial cell proliferation, migration and tube formation, showed that beta-carotene downregulated many transcription factors and inhibited proliferation, migration and tube formation of endothelial cells .
 Upadhyaya KR, Radha KS, Madhyastha HK. "Cell cycle regulation and induction of apoptosis by beta-carotene in U937 and HL-60 leukemia cells." J Biochem Mol Biol. 2007 Nov 30;40(6):1009-15.
 Meyer F, Bairati I, Jobin E, Gélinas M, Fortin A, Nabid A, Têtu B. "Acute adverse effects of radiation therapy and local recurrence in relation to dietary and plasma beta carotene and alpha tocopherol in head and neck cancer patients." Nutr Cancer. 2007;59(1):29-35.
 Guruvayoorappan C, Kuttan G. "Beta-carotene inhibits tumor-specific angiogenesis by altering the cytokine profile and inhibits the nuclear translocation of transcription factors in B16F-10 melanoma cells." Integr Cancer Ther. 2007 Sep;6(3):258-70.