Freezing Cancer Out: Cryotherapy for Upper GI Lesions
Many patients with Barrett’s esophagus or upper gastrointestinal (GI) tumors are of advanced age and not good candidates for surgery. Others may refuse invasive operations like the Ivor-Lewis, in which the lower part of the esophagus is removed and the stomach pulled up in the chest and attached to the remnant esophagus, out of fear of complications or prolonged recovery times.
Radiofrequency ablation (RFA), which destroys the abnormal cells by the application of heat, has been the mainstay of treatment for these patients. Evidence supports both the efficacy of RFA in treating these cancers and the durability of those results. However, patients can experience considerable pain after RFA. And, because contact must be made between the probe and the tissue, some areas in more angulated regions can be difficult to reach.
Cryotherapy using truFreeze® spray (CSA Medical, Lutherville, MD) offers an alternative to patients who do not respond to or cannot tolerate RFA. Unlike RFA, which uses extreme heat to kill precancerous and cancerous cells, cryotherapy uses extreme cold. Liquid nitrogen is introduced into the working channel of an endoscope and then converted to gas as it leaves the catheter, freezing tissue without requiring actual contact, meaning that more hard-to-reach areas can be treated. Patients typically undergo two to three sessions of cryotherapy to achieve desired results.
Since acquiring the technology in February 2013, Brenda J. Hoffman, M.D., Professor of Medicine in the Division of Gastroenterology & Hepatology and Chief of Endoscopic Ultrasound at MUSC’s Digestive Disease Center, has used cryotherapy to treat more than 50 patients with excellent results. Patients report considerably less chest pain and fever than with RFA and are less likely to have strictures. They can go home the day of surgery and can expect a quick recovery. Dr. Hoffman has found the technology to be especially useful in treating any form of adenocarcinoma or squamous cell carcinoma of the esophagus, particularly if carcinoma in situ, or early spreading tumors of the stomach in patients who are not good candidates for surgery. It is not appropriate for deeply ulcerated tumors.
Some of the best evidence for the efficacy of cryotherapy is provided by studies of patients with Barrett’s esophagus. In Barrett’s, persistent gastric reflux is thought to change the composition of the epithelium (from predominantly squamous cell to predominantly columnar, a change that seems to make the development of cancer more likely). A seminal paper showed that ablation of the precancerous cells could result in the regrowth of normal (squamous) tissue if the environment could be made less acidic by controlling backwash with medication.1 More recently, encouraging results have been reported with cryotherapy for both Barrett’s esophagus2 and localized esophageal cancer.3 More long-term studies are needed to examine the durability of the responses achieved with cryotherapy before it is considered a replacement for RFA.
Gaseous distention, sometimes a side effect of the older, bulkier iterations of cryotherapy that delivered variable bursts of nitrogen gas, now presents far less risk since the newer equipment ensures a steady stream of nitrogen. To further minimize any risk of gaseous distention, Dr. Hoffman suctions out gas in the region of intervention and uses cryotherapy only in the upper (ie, esophagus and stomach) and not the lower GI tract (ie, colon and small intestine), where distention could pose a greater risk.
MUSC is participating in trials to examine the efficacy and safety of cryotherapy using truFreeze® spray and to standardize its use in treatment. It will also serve as a training center for physicians nationwide in the safe and effective use of this technology.
² Shaheen NJ, Greenwald BD, Peery AF, et al. Safety and efficacy of endoscopic spray cryotherapy for Barrett’s esophagus with high-grade dysplasia.Gastrointest Endosc. 2010;71(4): 680-685.
³ Greenwald BD, Dumont JA, Abrams JA, et al. Endoscopic spray cryotherapy for esophageal cancer: safety and efficacy. Gastrointest Endosc. 2010;71(4): 686-693.