Available at http://www.cancercare.on.ca/cancerfacts. Changing patterns of esophageal cancer: adenocarcinoma on the rise (Sept. 2013) Adenocarcinoma and squamous cell carcinoma continue to show opposing trends. Obesity, GERD and Barrett esophagus are major risk factors for adenocarcinoma. Decreases in squamous cell carcinoma are related to decreases in smoking rates. Adenocarcinoma of the esophagus—one of the two main types of esophageal cancer—is on the rise. From 1981 to 2009, new cases, or incidence, of adenocarcinoma rose steadily at 4% per year, making it the most common type of esophageal cancer in Ontario.   This trend is in stark contrast to the incidence for the other main type of esophageal cancer—squamous cell carcinoma—which dropped from 1981 to 2009 at 2% per year. Similar trends have been reported in a national study, as well as in the United States, northern Europe, Australia and New Zealand.1,2 These trends are likely due to changes in the very different risk factors for each esophageal cancer type. The increase in adenocarcinoma may be related to the larger number of people who are obese or who have gastroesophageal reflux disease (GERD), a condition that causes stomach acid to spill into the swallowing pipe, or esophagus. Obesity also plays a role in the development of GERD, making those who are very overweight even more vulnerable to developing adenocarcinoma.2,3 GERD is a cancer risk factor because when stomach acid comes into contact with the esophagus, it can damage it and can cause a condition called Barrett’s esophagus, which can then lead to adenocarcinoma.2 Evidence is less clear for other risk factors, such as medications that relax the esophageal sphincter, gamma radiation from atomic detonation, and eating red meat and processed meats.3,4,5 Squamous cell carcinoma, on the other hand, is most strongly associated with tobacco smoke and alcohol, both of which act separately and together to increase risk.1 Decreasing smoking rates in Ontario probably explain the drop in number of new squamous cell carcinoma cases. Although esophageal adenocarcinoma continues to rise in Ontario, there are a few ways to lower the risk of developing this cancer. Eating more vegetables and fruit may reduce not only adenocarcinoma, but also squamous cell carcinoma.3 Exercising regularly and maintaining a healthy diet can also help because they reduce the chances of gaining weight and becoming obese, another adenocarcinoma risk factor. There is no strong evidence showing that drugs used for controlling stomach acid to treat GERD and Barrett esophagus reduce adenocarcinoma incidence, but certain acid-reducing medications have been proven to prevent the abnormal cell growth that can become adenocarcinoma.2   Esophageal cancer is a rare but highly fatal cancer, accounting for 1% of all cancers diagnosed in Ontario in 2009, and its overall incidence has changed little over the past few decades, despite the fluctuations in adenocarcinoma and squamous cell carcinoma. For more information, talk to your healthcare provider or call the Cancer Information Service at 1-888-939-3333. References Ferlay J, Shin HR, Bray F, et al. GLOBOCAN 2008 v1.2, Cancer Incidence and Mortality Worldwide: IARC CancerBase No.10 [Internet]. Lyon, France: International Agency for Research on Cancer. Available from http://globocan.iarc.fr. Accessed June 18, 2013. Otterstatter MC, Brierley JD, De P, et al. Esophageal cancer in Canada: trends according to morphology and anatomical location. Can J Gastroenterol 2012;26(10):723–27. Cancer Care Ontario. Risk factors in Ontario: evidence summary. Toronto, Canada, 2013. Available from http://www.cancercare.on.ca/riskfactor. Lagergren J. Etiology and risk factors for oesophageal adenocarcinoma: possibilities for chemoprophylaxis? Best Pract Res Clin Gastroenterol 2006;20(5):803–12. Salehi M, Moradi‐Lakeh M, Salehi MH, et al. Meat, fish, and esophageal cancer risk: a systematic review and dose‐response meta‐analysis. Nutrition Reviews 2013;71(5):257–67. Citation: Cancer Care Ontario. Cancer Fact: Changing trends of esophageal cancer: adenocarcinoma on the rise. Sept. 2013. Available at http://www.cancercare.on.ca/cancerfacts. Prepared by staff in Prevention and Cancer Control.