In addition to treating patients for over twenty years, Dr. Lawrence Cohen has served as a consultant to the pharmaceutical industry, has taught at the Mount Sinai Hospital Medical School, and has published over thirty papers in prominent medical journals. Recently, he has been involved in developing several groundbreaking new treatments for gastrointestinal disorders.
Reflux1: Tell us a little bit about how you got started in gastroenterology.
Dr. Cohen: I’ve been in gastroenterology about 23 years. I’ve been in practice for 20 years, and before that, I spent several years in training and research. I’ve been in the field since the early 1981.
I don’t think there was an exact point in time when I knew I wanted to go into gastroenterology. It was a feeling which evolved during medical school, nurtured further during my internship and residency at Mount Sinai Hospital, where I am still practicing today. My interest in gastroenterology has continued to blossom and grow since that time, even to this day. I really enjoy the practice and science of gastroenterology. Every day presents new challenges and rewards.
Reflux1: Since much of your recent work has been with GERD, could you please provide our users with a brief overview of heartburn and GERD, and explain the distinction between the two?
Dr. Cohen: Heartburn is a symptom. It’s described most often as a burning feeling. It typically occurs after meals, begins in the upper part of the belly and radiates upward toward the chest. It is often provoked by certain kinds of food -- fatty foods, alcohol or coffee --and may be aggravated by lying down, exercise, or straining.
GERD refers to the disease complex that results when stomach contents flow retrograde from the stomach back up into the esophagus. The "D" in GERD refers to the constellation of disorders that may result from gastroesophageal reflux, ranging from small ulcers on the lining of the esophagus (termed erosions), scarring and narrowing of the esophagus (referred to as a stricture), to a condition known as Barrett’s esophagus, in which the esophageal lining transforms in response to continued acid reflux. The importance of this later condition is the increased risk of developing esophageal cancer.
Reflux1: Can you tell our readers a little bit about the condition of Barrett esophagus, and the risks it poses?
Dr. Cohen: Barrett esophagus develops in 8-12% of patients with chronic gastroesophageal reflux. We don’t understand why a minority of patients with chronic GERD develop Barrett, while the majority of refluxers do not.
The risk of esophageal cancer for a patient with Barrett esophagus is increased 30-40 fold above the general population. While this may seem like an extraordinary risk, the absolute risk remains quite small, since the total number of new cases of esophageal cancer in the United States each year is quite small, about 7,500. Often, a patient with Barrett’s esophagus will ask, "What are my chances of developing cancer?" To the best of our knowledge, the risk is 0.4-0.5% per year; or, a half of one percent per year.
Reflux1: Does this mean that patients with Barrett’s esophagus shouldn’t worry much about esophageal cancer?
Dr. Cohen: We recommend that they understand the issue, and that they be treated for reflux, since there is some evidence that aggressive medical therapy may reduce the risk. We discuss the relative risks and weigh the option of periodic endoscopic examination as a way of helping to detect cancer or precancerous change.
Reflux1: You mentioned that you’ve personally been involved in some new methods of diagnosing and treating Barrett’s esophagus. What can you tell us about your own work?
Dr. Cohen: We’re currently doing a study of patients with Barrett’s esophagus. We are interested in assessing the adequacy of pharmacologic therapy in patients with Barrett esophagus. Specifically, we are attempting to ascertain whether acid reflux is adequately controlled in Barrett patients when medications are adjusted based upon symptoms and and/or the presence of erosive esophagitis. Using a new technology to quantify reflux, the BRAVO capsule, we can accurately measure acid reflux over periods of 24-48 hours. Our preliminary work shows that some patients with Barrett esophagus will continue to have significant amounts of acid reflux despite the use of large doses of acid-inhibitory medication.
For several years, we have also been involved in the development of endoscopic treatments for GERD, and we participated in the pre-clinical trials for a new endoscopic therapy for GERD referred to as Enteryx®. In this procedure, a small volume of a tissue-compatible polymer is injected into the lower esophagus. This treatment "stiffens" the sphincter valve, reducing the propensity for the valve to open and allow reflux to occur. The majority of patients treated with this device have had a favorable response to therapy, with about 85% of treated patient either off all treatment, or using significantly less medication at 12 months following treatment. The data for Enteryx®, both in terms of safety and efficacy compare favorably with other endoscopic therapies currently available.
At the present time, treatment options for reflux include either medication, or one of the invasive treatments (endoscopic or surgical treatment). Surgical treatment is a good option for some patients, although there are failures of surgery. Endoscopic treatment offers the advantages of being less invasive than surgery, with good efficacy and an easier and faster recovery. I believe that endoscopic therapy for GERD will bridge the treatment gap for patients with chronic GERD, who are currently forced to choose between lifelong medication and surgery.
Reflux1: If Enteryx® can bring an end to long-term treatment, is it a more cost-effective option for the average patient?
Dr. Cohen: We don’t have enough data at this time to answer that question. We need long-term durability data for the endoscopic therapies. However, we do know that as many as 60% of patients having anti-reflux surgery will be back of medical treatment for their GERD within 10-13 years of their operation.
Reflux1: Where would you recommend that our readers go for more information about heartburn or reflux?
Dr. Cohen: Two of the best web sites providing information to the public on digestive and liver disorders belong to the American Gastroenterological Association (www.gastro.org) and the National Institute of Diabetes, Digestive and Kidney Disease (www.niddk.nih.gov).
Reflux1: You mentioned that you were pursuing a new method of sedation for patients undergoing endoscopy or esophageal motility. Can you tell us more about this new method? Why is it so promising?
Dr. Cohen: For the past three years, we have been working to with a new form of sedation for endoscopic procedures, using a sedative agent termed propofol. This drug has been around since about 1990, and has been used mostly by anesthesiologists for patients undergoing surgical procedures. In the last several years there’s been growing interest in the use of this agent during endoscopic exams.
In the United States, the vast majority of all endoscopic exams are performed with sedation, and the majority of these are performed using a combination of an opioid (a narcotic painkiller) and a sedative agent. These agents are very effective; however, they have the disadvantage of having a prolonged effect, lasting up to six hours following completion of the exam.
Propofol is an ultra-short acting sedative with a half-life of one-and-a-half to four minutes. It provides patients with a pleasant, comfortable endoscopic procedure, on the one hand, but due to its very short duration of effect, patients can recover from their procedure within 10-15 minutes. In most cases, patients will return to work or their normal activity within an hour of their exam.
At the current time, e have used this agent in over three thousand patients. We have established a written protocol for its use, in an effort to make the drug safe and effective for more widespread use by gastroenterologists and other non-anesthesiologists.
Reflux1: What other treatment therapies are available for patients suffering from reflux? Are there any new promising treatments that you’re using in your practice?
Dr. Cohen: Enteryx® is the new boy on the block. This injectable form of treatment appears to offer patients with GERD a viable option to the traditional GERD treatments of medication and surgery. For carefully selected patients, Enteryx is an excellent treatment. It has an outstanding safety profile, and provides patients the opportunity to control their reflux symptoms without medication.
Reflux1: A while ago, we were talking about the difference between heartburn and GERD. What other gaps currently exist in patient knowledge of heartburn treatments? In other words, what are the most important things that heartburn patients don't know?
Dr. Cohen: It is important to recognize that heartburn is a symptom, rather than disorder, and the causes of this symptom are heterogeneous. Heartburn may result from GERD, or it may be a condition referred to as "functional heartburn." Functional heartburn is a poorly understood condition, with symptoms that are virtually identical to classic heartburn, except that patients with this disorder do not have an increase in esophageal acid exposure, and their symptoms have little if any correlation with acid reflux episodes. The causes of this condition are unknown, and treatment has not been well established.
Reflux1: What would the perfect treatment for reflux look like, in your opinion?
Dr. Cohen: The perfect treatment for GERD would be one that would correct the underlying mechanisms of GERD, namely a defective barrier between the stomach and the esophagus. Ideally, the treatment would provide long-term efficacy and durability, and possess an excellent record of safety. For today, I believe that none of our treatments come close to offering this level of benefit, although the endoscopic therapies are perhaps our greatest hope for such a treatment in the future.