Editorial: shedding some light on the etiology of adenocarcinomas of the esophagus and gastric cardia.
Am J Gastroenterol. 2012 Dec;107(12):1814-6. doi: 10.1038/ajg.2012.337.
1] Veterans Affairs Center for Clinical Management Research, Ann Arbor, Michigan, USA
2] Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
Environmental and behavioral factors likely have large roles in the etiology of adenocarcinomas of the esophagus and gastroesophageal junction. Prior ecological analyses suggest a protective effect of exposure to UV radiation for these cancers. But such analyses are prone to particular forms of bias. In this issue of The American Journal of Gastroenterology, new individual-level data is presented supporting such an association. Presumably, this is mediated by vitamin D, but definitive evidence is lacking. Supplementation with vitamin D aimed at preventing these cancers cannot be recommended at this time. More study regarding the role of vitamin D in Barrett's esophagus and these cancers are needed.
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The American Journal of Gastroenterology 107, 1803-1813 (December 2012)
Bich Tran, Robyn Lucas, Michael Kimlin, David Whiteman, Rachel Neale and for the Australian Cancer Study
Ecological studies have suggested an inverse relationship between latitude and risks of some cancers. However, associations between solar ultraviolet radiation (UVR) exposure and esophageal cancer risk have not been fully explored. We therefore investigated the association between nevi, freckles, and measures of ambient UVR over the life-course with risks of esophageal cancers.
We compared estimated lifetime residential ambient UVR among Australian patients with *esophageal cancer (330 esophageal adenocarcinoma (EAC),
- 386 esophago-gastric junction adenocarcinoma (EGJAC), and
- 279 esophageal squamous cell carcinoma (ESCC)), and
- 1471 population controls.
We asked people where they had lived at different periods of their life, and assigned ambient UVR to each location based on measurements from NASA's Total Ozone Mapping Spectrometer database. Freckling and nevus burden were self-reported. We used multivariable logistic regression models to estimate the magnitude of associations between phenotype, ambient UVR, and esophageal cancer risk.
Compared with population controls, patients with EAC and EGJAC were less likely to have high levels of estimated cumulative lifetime ambient UVR (EAC odds ratio (OR) 0.59, 95% confidence interval (CI) 0.35–0.99, EGJAC OR 0.55, 0.34–0.90). We found no association between UVR and risk of ESCC (OR 0.91, 0.51–1.64).
The associations were independent of age, sex, body mass index, education, state of recruitment, frequency of reflux, smoking status, alcohol consumption, and H. pylori serostatus. Cases with EAC were also significantly less likely to report high levels of nevi than controls.
These data show an inverse association between ambient solar UVR at residential locations and risk of EAC and EGJAC, but not ESCC.
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They got an association without even taking into account
- skin color,
- amount of sun screen used,
- amount of time out of doors in the middle of the day (gardening, etc)
- amount of clothing worn
- if they vacationed in sunny areas in the winter