Cancer chemoprevention by supplemental carotenoids and synergism with retinol in mastodynia treatment.

Cancer chemoprevention with beta-carotene (BC), canthaxanthin (CX) and retinol-BC is reported with respect to skin, breast, gastric, colon carcinogeneses induced by benzo(a)pyrene (BP) with or without ultra violet radiation (UV-A, UV-B), dimethylbenzathracene (DMBA) +/- UVB, P-UVA, N-methyl-N'-N-nitro-nitrosoguanidine (MNNG), dimethylhydrazine (DMH), and with respect to transplanted tumours. When animals were loaded with carotenoid supplementation one month before the carcinogenic induction (continued throughout the experiment), cancer prevention was observed up to 60-100%. The absence of provitamin A-activity in CX shows the carotenoid antioxidant property. Fifteen patients given BC + CX to prevent recurrences after radical removal of the primary neoplasia in organs like lung, breast, colon, urinary bladder, head and neck were studied in 1980-89. A longer than expected disease-free interval was preliminarily found. Supplementation of BC +/- retinol was also reported to prevent and treat oral leucoplakia. Supplementation and intermittent retinol administration was also tested in benign cyclical mastalgia with clear cut side effect free therapeutic results.