1. ¹Department of Epidemiology, Cancer Institute (Hospital), Chinese Academy of Medical Sciences, Beijing, People's Republic of China
2. ²Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
3. ³Departments of Preventive Medicine & Biometrics, University of Colorado Health Sciences Center, Denver, CO, USA
4. ⁴Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA

Correspondence: Dr CC Abnet, Investigator, Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, 6120 Executive Blvd, EPS/320, MSC 7232, Rockville, MD 20852, USA. E-mail: abnetc@mail.nih.gov; Dr Y-L Qiao, Department of Cancer Epidemiology, Cancer Institute, Chinese Academy of Medical Sciences, 17 S Panjiayuan Lane, Chaoyang District, PO Box 2258, Beijing 100021, China

Received 12 April 2007; Revised 11 May 2007; Accepted 11 May 2007; Published online 5 June 2007.

Abstract

We prospectively examined the relation between pretrial serum vitamin D status and risk of oesophageal and gastric cancers among subjects who developed cancer over 5.25 years of follow-up, including 545 oesophageal squamous cell carcinomas (ESCC), 353 gastric cardia adenocarcinomas, 81 gastric noncardia adenocarcinomas, and an age- and sex-stratified random sample of 1105 subjects. The distribution of serum 25(OH)D was calculated using the known sampling weights. For the cohort as a whole, the 25th, 50th, and 75th percentile concentrations of 25(OH)-vitamin D were 19.6, 31.9, and 48.7 nmol l^-1, respectively, and we found that higher serum 25(OH)D concentrations were associated with monotonically increasing risk of ESCC in men, but not in women. Comparing men in the fourth quartile of serum 25(OH)D concentrations to those in the first, we found a hazard ratio (HR) (95% confidence interval (CI)) of 1.77 (1.16–2.70), P trend=0.0033. The same comparison in women had a HR (95% CI) of 1.06 (0.71–1.59), P trend=0.70. We found no associations for gastric cardia or noncardia adenocarcinoma. Among subjects with low vitamin D status, higher serum 25(OH)D concentrations were associated with significantly increased risk of ESCC in men, but not in women. Further refinements of the analysis did not suggest any factors, which could explain this unexpected result.