Navy Doctor Pioneers Esophagus Treatment Technique

(I-Newswire) April 20, 2005 - Capt. (Dr.) Mark Johnston is making medical history with his innovative use of "cryotherapy," the application of extreme cold, for the treatment of serious esophageal diseases.

Johnston said the freezing technique has been used for decades in treating certain cancers and in various dental and pulmonary procedures. But this marks the first time the technique, which dates back to the 1850s, is being used in the field of gastroenterology for esophageal mucosal ablation and other diseases, he said.

Johnston holds many credentials. He's chief of gastroenterology and director of the Colon Cancer Center at Bethesda. He's also an associate professor of medicine at the Uniformed Services University of Health Sciences and a gastroenterology consultant to the U.S. Congress, Supreme Court and White House.

Johnston said Barrett's is a condition in which the esophagus, the muscular tube that carries food and saliva from the mouth to the stomach, changes so that some of its lining is replaced by tissue similar to that normally found in the intestine. "Once you get that kind of cell, your risk for getting cancer in the esophagus can go up over a hundredfold," he noted.

Barrett's esophagus can lead to two common forms of esophageal cancer -- squamous cell carcinoma and adenocarcinoma. Over the last 25 years, the incidence of esophageal cancer has increased faster than any other malignancy in the Western world, Johnston noted.

"When acid comes up and burns off the lining of your esophagus, in most people, when it heals, it will heal back with the normal tissue," Johnston said. "In some people, it heals back with abnormal tissue, which is what we call Barrett's esophagus. And it's that tissue that's at risk for turning into cancer."

It's still in the testing and research and development stage, but Johnston's freezing technique replaces surgery with an outpatient procedure that takes only 15 to 20 minutes, and it's pain-free, Johnston noted.

"When it's over, the patient can get up and walk down to the coffee shop and have a cup of coffee, or a hamburger -- no problem," he said. "So we went from an esophagectomy that results in being in the hospital from seven to 21 days, to walking in, getting your procedure and walking out in time to have lunch."

The doctor has successfully treated more than 25 patients, including two with high-grade dysplasia, a close precursor to cancer, which normally would have been treated with an esophagectomy, he said. "We've reversed Barrett's in every single one of them," he added. "We've had no complications – zero – in a first-of-its-kind study."

One standard treatment for high-grade dysplasia is either an esophagectomy or an experimental ablation, the doctor noted. "An esophagectomy means cutting out the esophagus completely and pulling the stomach up into the chest and sewing it up into the neck," he said. "It's a very gruesome operation."

An experimental ablation means removing the lining of the esophagus with a laser or some other technique, which also has all kinds of major problems and expense. This procedure is followed by multiple biopsy follow-ups every three month until the cancer is gone, the surgeon said.

"These techniques are very difficult and expensive to perform," Johnston said. "So in 1994, I said, 'Man, there has got to be a better way.'"

Johnston started thinking about a gentler and less invasive method of treating esophagus diseases in October 1994 during an American College of Gastrology meeting at the Uniformed Services University of the Health. "I thought, 'Why not freeze the esophagus?'" he said. "Dermatologists had been freezing skin cancer for decades. Gynecologists have been freezing dysplasia, early cancer in the cervix in women, just by spraying it. Why not just spray the lining of the esophagus, just like other specialties have been doing for a long time?"

When he returned to his office, he absorbed himself in a big Internet literature search. "I found out that spraying and freezing the lining of the esophagus had never been done before – not a single abstract, no report, nowhere in the world in medical literature," Johnston. "So it was a new idea."

After talking it over with his mentor, Andre Dubois, a research professor at the university, Johnston went home and built a prototype device in his garage.

After becoming a staff doctor at the Bethesda naval hospital in 1995, Johnston found out that the university had a $12,000 starter grant earmarked for young investigators to encourage development with new ideas and to get them involved in research. He managed to obtain some money for his research.

Deciding to use pigs for his experiment, Johnston said the question was, "Can you freeze the lining of the esophagus, blister it off and do it safely without hurting the pigs and have it heal with normal tissue?"

After successful trials on 20 pigs, a friend suggested that he patent his device. "I hadn't even thought about patenting it," Johnston said. "I was just trying to solve this problem of Barrett's. And being a naval officer, patenting something is a problem."

Johnston asked a Defense Department intellectual property attorney how to handle patenting his invention and was told to file for a determination of rights, which assesses who has ownership of the intellectual property. Navy officials deemed that they had insufficient interest in Johnston's device. "Therefore," he said, "they allowed me to pursue patenting it, but if it ever came to marketability, the Navy would be allowed to buy it royalty free. So the determination of rights was in my favor, and I began to pattern the concept."

Pursuing the pattern cost him a fortune, he said, all of which he paid out of his own pocket. "As a young Navy lieutenant commander, I literally couldn't afford anymore," he noted. "I spent several thousand dollars with no promise that this would ever amount to anything."

CryMed Technologies decided to pick up the tab and develop the device, but that presented a major Navy issue about conflicts in dealing with private industry, Johnston said.

It became a Catch 22: The Navy said if he entered into a royalty agreement, he couldn't be an investigator in any way. Or he could be an investigator, but he would have to permanently divest himself of any royalties. So he permanently designated all royalties to a charity so he could continue his work on the concept. "I gave the royalties to a charity devoted to humanitarian missions," he said.

The Navy doctor's quick, painless technique could be a godsend for people around the world. More than 7 million people in the United States experience acid reflux disease, which affects an estimated 5 to 7 percent of the global population, including men, women and children, Johnston said. Barrett's esophagus, which may cause no symptoms itself, is estimated to affect about 700,000 adults in the United States alone.

Johnston told of a 74-year-old patient he has been treating for years. "He had cancer of the esophagus about 12 years ago at another location and it was cured with radiation chemotherapy," the doctor said. "But in the process of getting cured, he had maximum doses of radiation."

Therefore, it was too dangerous to treat the patient with more chemotherapy, Johnston said.

Johnston told the other doctors whom the patient was seeing at the time that he'd had phenomenal success treating patients with cryoablation and asked if he could treat the patient since there wasn't any other therapy available.

"So we treat him with cryo – nothing else," Johnston said. "We treat him with one treatment – takes 15 minutes. We bring him back in a month and the tumor is radically shrunk. But the biopsy shows that there's still some tumor there. We bring him back another month and recryo what's left. We bring him back in another month and it's totally gone. We biopsied it. No tumor. Totally gone.

"That was the first treatment of this kind of cancer in the world and he's in total remission," Johnson continued. "So we're having super success and we're the only place in the world doing it."



By Rudi Williams
American Forces Press Service

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