TABLE 3.
Published and ongoing clinical studies on tocopherols and tocotrienols for cancer prevention or therapy1
| Study design (ref) | Subjects or purpose of study | Vitamin E forms | Outcomes |
| Breast cancer | |||
| TRF on breast cancer: double-blinded, placebo-controlled intervention (169) | Women aged 40–60 y, with tumor node metastases stage I or II breast cancer or estrogen receptor; 120 subjects in each group; the study lasted for 5 y | Control: 20 mg TAM with placebo (soybean oil); intervention: TRF at 200 mg + 20 mg TAM | No statistical difference between TAM and TAM + tocotrienols in mortality rate |
| Tocotrienols in combination with neoadjuvant chemotherapy (NCT02909751) | Whether tocotrienols can improve the efficacy and reduce the side effects of chemotherapy before surgery for breast cancer | Tocotrienol, daily 300 mg ×3 along with chemotherapy drugs | Correlation of changes in NK cells, or ctDNA, with pathological response; grade 3–4 side effects |
| Pancreatic cancer | |||
| Window-of-opportunity preoperative trial: open-label, phase I trial (16) | 25 patients for curative surgical resection with presumptive premalignant or malignant neoplasms of exocrine pancreas | δTE at escalation doses of 200–3200 mg/d for 2 wk before surgery | δTE is generally safe and induced apoptosis in dysplastic or malignant tissues from pancreas |
| CRC | |||
| γTmTs on CRC: randomized early phase I trial (NCT00905918) | Patients undergoing surgery for colorectal cancer | γTmTs for 1 or 2 wk | Bioavailability, plasma F2-isoprostane, inflammation markers |
| Tocotrienols as adjuvants for treatment of CRC, randomized and double-blinded (NCT02705300) | Side effects to Folfoxiri + tocotrienol/placebo as first-line treatment of metastatic colorectal cancer | Standard chemotherapy plus tocotrienol, daily 300 mg ×3 | Side effects and survival benefits |
| Prostate cancer | |||
| γTmTs on prostate cancer: randomized early phase I trial (NCT00895115) | Patients at risk of prostate cancer or who have prostate cancer | γTmTs for 1 or 2 wk | Bioavailability, plasma PSA, F2-isoprostane, inflammation markers |
| Ovarian cancer | |||
| Cabazitaxel vs. tocotrienol: a phase 2 randomized, open-label study; crossover (NCT02560337) | Patients with recurrent ovarian cancer after failure of standard therapy | Cabazitaxel (25 mg/m2) vs. tocotrienol (300 mg ×3); 3 mo | Survival rate and cancer progression |
| Tocotrienols as a nutritional supplement with bevacizumab; phase 2, single-group assignment (NCT02399592) | Patients with advanced ovarian cancer | Bevacizumab plus tocotrienol, 300 mg | Disease progression |
| Lung cancer | |||
| Tocotrienols as nutritional supplement; randomized, double-blind (NCT02644252) | In patients with advanced NSCLC | Tocotrienol, 300 mg ×3 plus standard chemotherapy | Disease progression–free survival |
Data were from published data and https://clinicaltrials.gov. This table shows non-αT vitamin E forms for cancer prevention or treatment in ongoing or published trials, whereas large trials that focus on αT have been extensively reviewed elsewhere (4, 6). This table does not include the studies whose sole purpose is for obtaining pharmacokinetic data, in which vitamin E forms are used as part of other dietary factors or antioxidants, or where the vitamin E form was not clearly identified. For those ongoing (unpublished) studies, the clinicaltrials.gov identifiers (NCT) are indicated. CRC, colorectal cancer; ctDNA, circulating tumor DNA; NSCLC, non–small cell lung cancer; PSA, prostate specific antigen; ref, reference; TAM, tamoxifen; TRF, tocotrienol-rich fraction; αT, α-tocopherol; γTmT, γT-rich mixed tocopherol; δTE, δ-tocotrienol; X3, 3 times/d.