Vitamin E as Cancer Treatment Vitamin E succinate (VES, alpha tocopherol succinate),has generated some interest as an adjunctive cancer therapy recently. VES demonstrated growth inhibition of human B-cell lymphoma77 and estrogen receptor-negative breast cancer78 cell lines in vitro. Vitamin E at 3 mM concentration arrested tumor cells in the G1 phase of the cell cycle, leading to apoptosis.7 Recent research on human oral squamous carcinoma cells suggests the VES effect is biphasic; growth stimulatory at physiological concentrations, while pharmacological concentrations are inhibitory.79 A phase I trial of intravenous vitamin E in treatment refractory neuroblastoma found mild toxicity (tendency toward increased bleeding time was noted) at doses below 2,300 mg/m2. Five of 13 patients experienced pain relief and/or tumor regression with treatment. No complete remissions resulted from treatment.80 Vitamin E, 200 mg daily, given together with 18 g/day omega-3 fatty acids from fish oil, prolonged survival in patients with generalized malignancy in a randomized controlled trial. Improvement in T-helper/suppressor ratio was also noted with treatment.81 Phase I clinical trials are being planned or are underway in patients with breast and prostate cancers.82 Vitamin E and its derivatives are particularly attractive therapeutic agents due to their remarkable lack of toxicity in vivo.83 Vitamin E with Radiation The picture here is unfortunately far from clear. An initial report showed mice treated with 1 g/kg of vitamin E had an increased in the lethal radiation dose (LD50). Unfortunately, squamous cell carcinoma cell lines treated in this study were less radiosensitive, with 35-percent cell survival versus 13 percent in controls.84 A later experiment was able to replicate this finding in vitro in cells incubated for several weeks with vitamin E, but not those in which it was added immediately before irradiation.85 The latest experiment to look at this issue actually found that some doses of vitamin E enhanced mouse sarcoma tumor cell kill. Intraperitoneal pretreatment with 50, 250, and 500 mg/kg, but not 1000 mg/kg, led to better tumor response than radiation alone. The authors also noted that intramuscular and oral tocopherol administration had a similar effect.86 From these results it would appear vitamin E doses used in humans increase the effect of radiotherapy, and super-human doses (above 35,000 IU) may blunt the therapeutic efficacy of radiotherapy. Radiation-induced fibrosis is a sequela to irradiation therapy which does not spontaneously regress. A combination of vitamin E (1000 IU/day) and pentoxifylline (800 mg/day) completely reversed a case of radiation-induced cervicothoracic fibrosis in a 67-year-old woman after an 18-month course of treatment. The findings were confirmed with CT scan. A phase II trial is currently underway to confirm these results.87 Vitamin E with Chemotherapy There are a few interesting recent reports on the concurrent use of vitamin E with chemotherapy. Vitamin E, 750 mg/kg intraperitoneally, given with 5-fluorouracil had a greater anti-tumor effect in mice bearing human colon cancer lines than either agent alone; treatment led to complete cessation of tumor growth. The same investigators found in vitro addition of vitamin E to either 5-fluorouracil or doxorubicin enhances the effect of these agents on human colon cancer cells.7 Another report showed pre-treatment with 85 mg (approximately 4000 mg/kg) alpha-tocopherol reduced the lethality of a single 15 mg/kg dose of doxorubicin from 85 percent to 10 percent in mice. This dose of tocopherol did not alter the suppression of tumor cell DNA synthesis by doxorubicin. The tumor-bearing mice pretreated with vitamin E lived longer on average than those treated with doxorubicin alone. The authors theorized the vitamin E blocked lipid peroxidation-mediated toxicity, while not impairing the anti-tumor property of doxorubicin.14 Both the toxicity prevention effect and the lack of inhibition of vitamin E toward doxorubicin were confirmed in a later experiment.89 In vitro experiments showed VES can enhance the cytotoxic effect of doxorubicin on human prostate cancer cells at concentrations easily attained in human plasma (5 mg/ml). This inhibition was found to be dose-dependent.89 Oral and intraperitoneal administration of vitamin E (20 mg/kg/day) enhanced the anti-tumor activity of cisplatin on neuroblastoma in mice.90 Alternative Medicine Reviews, 1999;4(5):304-329 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.