Positive Health Online

Abstract

QIAO and COLLEAGUES,  Cancer Institute, Chinese Academy of Medical Sciences, Beijing, Peoples Republic of China present a 10-year follow-up in the General Population Nutrition Intervention Trial, the randomized primary oesophageal and gastric cancer prevention trial in which participants in Linxian, China, were given daily vitamin and mineral supplements of selenium, vitamin E and beta-carotene.

Background

The General Population Nutrition Intervention Trial was a randomized primary oesophageal and gastric cancer prevention trial conducted from 1985 to 1991, in which 29,584 adult participants in Linxian, China, were given daily vitamin and mineral supplements. Treatment with 'factor D', a combination of 50 microg selenium, 30 mg vitamin E, and 15 mg beta-carotene, led to decreased mortality from all causes, cancer overall, and gastric cancer. Here, we present 10-year follow-up after the end of active intervention.

Methodology

Participants were assessed by periodic data collection, monthly visits by village health workers, and quarterly review of the Linxian Cancer Registry. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the cumulative effects of four vitamin and mineral supplementation regimens were calculated using adjusted proportional hazards models.

Results

Through May 31, 2001, 276 participants were lost to follow-up; 9727 died, including 3242 from cancer (1515 from oesophageal cancer and 1199 from gastric cancer). Participants who received factor D had lower overall mortality (HR = 0.95, 95% CI = 0.91 to 0.99; P = .009; reduction in cumulative mortality from 33.62% to 32.19%) and gastric cancer mortality (HR = 0.89, 95% CI = 0.79 to 1.00; P = .043; reduction in cumulative gastric cancer mortality from 4.28% to 3.84%) than subjects who did not receive factor D. Reductions were mostly attributable to benefits to subjects younger than 55 years. Oesophageal cancer deaths between those who did and did not receive factor D were not different overall; however, decreased 17% among participants younger than 55 (HR = 0.83, 95% CI = 0.71 to 0.98; P = .025) but increased 14% among those aged 55 years or older (HR = 1.14, 95% CI = 1.00 to 1.30; P = .47). Vitamin A and zinc supplementation was associated with increased total and stroke mortality; vitamin C and molybdenum supplementation, with decreased stroke mortality.

Conclusion

The beneficial effects of selenium, vitamin E, and beta-carotene on mortality were still evident up to 10 years after the cessation of supplementation and were consistently greater in younger participants. Late effects of other supplementation regimens were also observed.

References

Qiao YL, Dawsey SM, Kamangar F, Fan JH, Abnet CC,  Sun XD, Johnson LL, Gail MH, Dong ZW, Yu B, Mark SD and Taylor PR. Total and cancer mortality after supplementation with vitamins and minerals: follow-up of the Linxian General Population Nutrition Intervention Trial. Journal of the National Cancer Institute. 101(7): 507-18. Apr 1 2009. NLM. PMC2664089 [Available on 04/01/10].

Comment

This important study shows that the beneficial effects of selenium, vitamin E, and beta-carotene supplementation on oesophageal and gastric cancer mortality were still evident up to 10 years after the cessation of supplementation.