Use of vitamins, minerals, and nutritional supplements by participants in a chemoprevention trial

Abstract

BACKGROUND The growing use of vitamins, minerals, and nutritional supplements has the potential to influence the design and interpretation of randomized controlled trials of chemopreventive agents. To the extent that these complementary agents are effective, they could limit the ability of trials to demonstrate an effect of the agents under study. METHODS During the course of a colorectal neoplasia chemoprevention trial using aspirin in a group of colorectal carcinoma survivors, the authors obtained information on the use of vitamins, minerals, and supplements at baseline and every 6 months. The information from 622 study participants was categorized and enumerated. RESULTS One or more supplements were used at some time by 341 (55%) subjects. Among those who took supplements, 66% took more than 1 and 13% took 5 or more. The mean number of supplements taken was 2.6 (1.7 standard deviation). Vitamins were the most commonly used (49%), followed by minerals (22%), botanicals (13%), and others (5%). Among the vitamins, the most frequently used were multivitamins (38% of subjects), vitamin C (18%), and vitamin E (22%). Calcium (16%) was the most frequent mineral. Among users, there were no differences in supplement use by age or gender. CONCLUSIONS Supplement use was common among colorectal carcinoma survivors enrolled in a prevention trial. Investigators should record the information on supplement use so that the possible impact of the supplements on trial endpoints can be evaluated. It may be necessary to increase the size of studies if many of the subjects take potentially effective supplements. Cancer 2001;91:1040–5. © 2001 American Cancer Society.

Randomized trial of fenretinide (4‐HPR) to prevent recurrences, new localizations and carcinomas in patients operated on for oral leukoplakia: Long‐term results

“…25,[35][36][37] Three previous studies used retinoids to prevent second primaries in patients treated for head-and-neck cancer. 16,18,19 Hong et al 16 studied 103 patients who took isotretinoin for 1 year and found a significant reduction in the occurrence of new carcinomas but no difference in occurrence of relapses or metastases.…”

“…We found that the protective effect of 4-HPR against recurrences and new leukoplakias lasted for 7 months after drug withdrawal, though CIs were dependent on the size of the sample, both because of the original sample size and the fact that it reduced with follow-up. Formelli et al 37 found that 4-HPR and its metabolite 4-MPR were still present (at the limits of detection) 12 months after withdrawal in a chemoprevention study but were not detected 24 months after withdrawal. This persistence might explain the prolonged protective effect.…”

Integrative Medicine Consultation Service in a Comprehensive Cancer Center: Findings and Outcomes

“…2 Recently, studies confirmed that a majority of patients undergoing cancer therapy use self-selected forms of CIM. 3,4 Previous reports estimated that CIM was used by 20% to 55% of cancer patients 5,6 ; however, a survey administered at The University of Texas M D Anderson Cancer Center in 2000 revealed that its use was much higher, exceeding 80%. 3 Recent data confirm the high rate of use among breast cancer patients.…”

Nutraceuticals and Nutraceutical Supplementation Criteria in Cancer: A Literature Survey

“…Recently less reported and newly investigated cancer protection by nutraceuticals were evidenced for lymphoma [179], skin cancer [180], pancreatic cancer [181][182][183]. Recently vitamins and minerals were validated in chemoprevention trial of different cancers [184]. In other recent reports the investigators showed a positive response of different nutraceutical supplements and foods in cancer prevention of different organs in the body as shown in Table 3 with nutraceuticals and references.…”

“…In other recent reports the investigators showed a positive response of different nutraceutical supplements and foods in cancer prevention of different organs in the body as shown in Table 3 with nutraceuticals and references. Bone cancer soy isoflavones [5] Breast cancer lycopene, phytoesterogen [122][123][124][125][126][127][128][129][130][131][132] Common cancer cruciferous vegetables [25,184] Colon cancer nuts, fibers [158][159][160][161][162][163][164][165][166][167][168][169][170][171][172] Gastric cancer herbs [173][174][175] Intestinal cancer sphingolipids [64,65,176] Liver cancer silbinin, citrous flavonoids [25] Lung cancer vitamins A and E [154][155][156][157] Ovary cancer Vitamin A, D, antioxidants [176][177][178] Pancreatic cancer Vitamins and isoflavones …”