What is GERD?
Gastroesophageal reflux disease (GERD) occurs when the upper portion of the digestive tract is not functioning properly, causing stomach contents to flow back into the muscular tube linking the mouth to the stomach (esophagus). In normal digestion, a specialized ring of muscle at the bottom of the esophagus called the lower esophageal sphincter (LES) opens to allow food to pass into the stomach and then quickly closes to prevent backflow into the esophagus. The LES can malfunction, allowing contents from the stomach, including food and digestive juices, such as hydrochloric acid, to splash back into the esophagus. In GERD, this backflow is ongoing. Symptoms of GERD include heartburn, the sensation of food flowing up into the mouth, and a bitter or sour taste, as well as less common symptoms such as persistent sore throat, hoarseness, chronic coughing, difficult or painful swallowing, asthma, unexplained chest pain, bad breath, a feeling of a lump in the throat, and an uncomfortable feeling of fullness after meals. GERD affects 13-29% of the population.1
What is Barrett’s Esophagus?
The symptoms of Barrett’s esophagus are often mistaken for those of GERD. When investigating for GERD during endoscopy examination, physicians will notice Barrett’s esophagus in approximately one in ten patients. Symptoms include heartburn, food coming up with a burp, stomach ache, pain when swallowing, excess belching, hoarse voice, sore throat, coughing, shortness of breath, and wheezing. During the later stages of Barrett’s esophagus, there may be difficulty swallowing solids or liquids. Of note is that some patients report no symptoms at all.
Unlike the stomach, the normal squamous cell epithelium lining of the esophagus is not acid-resistant and it can become permanently damaged after ongoing acid irritation. Over time, metaplastic columnar epithelium cells that are similar to those found in the lining in the stomach or intestine form an abnormal esophageal lining.
Typically, a physician will monitor the esophageal changes closely, taking action to prevent the most severe form of Barrett’s esophagus, which is high-grade dysplasia. If left untreated, Barrett’s esophagus may progress to esophageal adenocarcinoma.
What is Esophageal Cancer?
Cancer of the esophagus can appear at any point along the length of the esophagus. There are two types of esophageal cancer, both of which occur when different cells in the esophagus become malignant: adenocarcinoma and squamous cell carcinoma. Adenocarcinoma develops in glandular cells at the lower part of the esophagus, and its main risk factors include GERD, Barrett’s esophagus, and obesity.Ten percent of individuals diagnosed with Barrett’s esophagus will have coexistent adenocarcinoma.2 Squamous cell carcinoma develops in the squamous cells, usually located in the upper and middle parts of the esophagus, and its main risk factors include smoking and drinking alcohol. Typically, by the time cancer symptoms appear, the tumour has progressed to a later stage, making treatment much more difficult. These symptoms include chest pain (radiating toward the back), fatigue, hoarseness, coughing, pain when swallowing, persistent heartburn, progressive difficulty swallowing (starting with solids, and eventually even liquids can become difficult to swallow), and weight loss.
In a 2010 report,3 the Canadian Cancer Society revealed that esophageal adenocarcinoma is on the rise in the Western world, whereas cases of squamous cell cancer are decreasing in Canada and the US, perhaps related to the increase in obesity and GERD in the Western world and the decrease in smoking in Canada and the US. In Canada, men are twice as likely to get adenocarcinoma, and women are twice as likely to get squamous cell carcinoma. In addition, men and individuals older than age 50 are much more likely than women and young people to have either type of esophageal cancer. From 2002-2006, 7,134 new cases of esophageal cancer were diagnosed in Canada. The chance of living for at least 5 years after diagnosis is only 14%, due largely to the fact that diagnosis usually comes too late for effective treatment.
Although esophageal adenocarcinoma is more common in Canada, esophageal squamous cell carcinoma has many more victims in the rest of the world.
The Latest Research
Fats and Your Esophagus
A recent study, published in the International Journal of Cancer,4 shows that eating high amounts of dietary fat, from both animal and plant sources, and a high intake of cholesterol may result in an increased risk of developing adenocarcinoma. However, this study also found that dietary fat or cholesterol does not increase the risk of Barrett’s esophagus.
Reflux May not be Such a Big Risk-Factor for Adenocarcinoma
Another study, published in the American Journal of Gastroenterology,5 investigated whether having GERD increases a person’s chances of developing this cancer, and found that in individuals with chronic GERD who were female or younger than 50 years of age, the incidence of adenocarcinoma was very low. For example, in women of all ages, the incidence of adenocarcinoma is about the same rate as male breast cancer. This means that regular screening is unnecessary for these individuals. However, researchers found that in men older than 60 years of age, the incidence of esophageal adenocarcinoma was quite substantial, so screening may be useful for that group.
Less Pain; More Diagnoses
An interesting new study from the journal, Archives of Surgery,6 shows that individuals suffering from GERD who have fewer symptoms are more likely to get adenocarcinoma or Barrett’s esophagus than those who experience severe GERD symptoms. These findings were even more pronounced for those who had GERD for 10 or more years, and those whose symptoms were masked by acid suppression therapies like proton pump inhibitors (PPIs).
Acid suppression therapy is the best treatment we currently have for those with GERD, but it does not decrease refluxing episodes; it just makes the refluxing contents less acidic, thereby reducing symptoms. Even though the reflux content is less acidic, it is still a bit too acidic, and over time it can have a mutagenic effect on the esophageal tissue. Since the patient doesn’t feel pain or discomfort, they do not report symptoms to their physician, who, therefore, is not alerted to test the individual for esophageal problems. This study shows that it is important for all individuals with GERD to have regular endoscopies to look for adenocarcinoma and Barrett’s esophagus, whether or not they are taking PPIs.
In 2004 and 2005, the Canadian healthcare system spent $52,235,910 on hospital stays for 7,554 patients ($6,915 each) who had a primary diagnosis of diseases of the esophagus and associated complications.7