More than 70% of patients with early-stage disease had no evidence of cancer after treatment
Treatment with a freezing technique known as cryotherapy can eliminate esophageal cancer in a significant proportion of patients with localized disease, according to a new study led by a University of Maryland gastroenterologist.
Bruce D. Greenwald, M.D., a gastroenterologist at the University of Maryland Medical Center and professor of medicine at the University of Maryland School of Medicine, said 79 patients with early-stage esophageal cancer who were treated with liquid nitrogen spray through an endoscope were enrolled in the study. Of 44 patients who have completed the treatment, 70.5 percent (31 patients) had a complete response to the therapy, showing no evidence of cancer after being treated. Doctors followed these patients for nearly 11 months.
“This study demonstrates that spray cryotherapy is effective in eliminating esophageal cancer in a substantial portion of cases. It is also an excellent alternative treatment for patients with localized disease who are not eligible for or choose not to have standard therapies,” says Dr. Greenwald, the lead author of the study, which was conducted at the University of Maryland Medical Center and nine other institutions. He recently presented the initial results of the study at the 2009 Digestive Disease Week (DDW) conference in Chicago.
“We see a number of patients, particularly older people, who are not able to have surgery or are too ill to tolerate chemotherapy and radiation. With this technology, we can offer them a treatment option where previously there was none,” Dr. Greenwald says. The average age of patients in the study was 76 years old.
In this outpatient procedure, doctors spray liquid nitrogen on the cancerous tissue using specially designed equipment threaded into the esophagus through an endoscope, which is a thin, fiber-optic instrument inserted through the mouth to enable a doctor to see inside the digestive tract. The patient is under moderate sedation.
The liquid nitrogen freezes the cancerous tissue, which then thaws and ultimately sloughs off. This provides an opportunity for normal tissue to grow back in its place. Each area is frozen and thawed multiple times. Treatments are repeated every two to six weeks. Patients are monitored very closely to make sure the cancer does not return.
Of the 31 patients in the study who showed no evidence of cancer after treatment, 16 of them experienced a return of normal tissue in the esophagus. The remaining patients showed evidence of some abnormal cells, called intestinal metaplasia or dyplasia, but not cancer. Thirty-five patients were still receiving treatment. He notes that the goal of this treatment initially was to help relieve symptoms of the cancer. “However, the initial results of this study demonstrate the curative effects of cryotherapy on some localized esophageal cancers,” he says.
E. Albert Reece, M.D., Ph.D., M.B.A., vice president for medical affairs at the University of Maryland and dean of the University of Maryland School of Medicine, says, “Dr. Greenwald has played a key role in testing the safety and efficacy of this novel new approach to treating cancers and pre-cancerous conditions of the esophagus. Esophageal cancer is on the rise in this country, and we need to develop effective new ways to treat it. His findings appear to be very encouraging.”
The U.S. Food and Drug Administration has cleared the Cryospray Ablation system, manufactured by a Baltimore-based company, CSA Medical, Inc., for use in destroying unwanted tissue in the body. An earlier small study showed the therapy was safe and could reduce or eliminate localized esophageal cancer.
The University of Maryland Medical Center was one of the first centers to use spray cryotherapy to treat early-stage esophageal cancers and a pre-cancerous condition known as Barrett’s esophagus with high-grade dysplasia. Also presented at the DDW conference were the results of another multi-center study, co-authored by Dr. Greenwald, which showed that cryotherapy was safe and effective in treating Barrett’s esophagus with high-grade dysplasia.
In addition, Dr. Greenwald reported in the journal Diseases of the Esophagus in Junethat the freezing therapy completely eliminated high-grade dysplasia in 94 percent of patients with Barrett’s esophagus in a study at the University of Maryland Medical Center and three other institutions. All seven patients with early-stage esophageal cancer and intramucosal carcinoma (cancer of the lining of the esophagus) in the study showed complete regression of cancer after the treatment.
The cryotherapy ablation system is now being used at 68 institutions. More than 1,000 patients have been treated nationwide, according to CSA Medical. For more information about the system, visit www.csamedical.com.
The University of Maryland Medical Center offers a wide range of treatment options for patients with gastrointestinal cancers and other GI disorders. For more information, go to www.umm.edu/gi/.