City of Hope researchers have shown that combining TomoTherapy with robotic esophageal surgery and chemotherapy may improve efforts to fight cancer of the esophagus, which has historically been difficult to treat.
The physicians presented their findings at the American Society for Therapeutic Radiation Oncology Annual Meeting in Los Angeles, held from Oct. 28 to Nov. 1.
“Our initial results are encouraging,” said Yi-Jen Chen, M.D., clinical assistant professor of radiation oncology and a study author. “We plan to continue this treatment approach and refine it to benefit our patients, and perhaps influence care at other centers.”
The multidisciplinary research team studied 20 patients treated at City of Hope from 2005 to 2007 for locally advanced esophageal cancer — a group in which the vast majority would likely die of cancer without any treatment within 12 months, physicians said. All patients received chemotherapy and radiation therapy; some also were able to undergo surgery after their radiation treatment.
Radiation oncologists provided their treatments using the TomoTherapy Hi-Art System. Through TomoTherapy, radiation oncologists not only can administer therapy, but they also can create images through computed tomography (CT) to precisely target a tumor.
The system integrates two features: spiral CT scanning and intensity modulated radiation therapy. TomoTherapy uses hundreds of pencil beams of radiation of varying intensity that rotate 360 degrees around a tumor while the patient moves through the machine.
As a result, physicians can administer radiation doses more evenly within esophagus tumors, while also sparing the nearby vulnerable, healthy structures of the neck, chest and upper abdomen.
In this study, the physicians began by providing patients with a combination of chemotherapies. Then, while patients were still on the drugs, they administered radiation using TomoTherapy to the tumors and nearby areas where tumors may have spread.
Afterward, 10 of the 20 patients were able to undergo surgery through City of Hope’s robotic methods, which involve removing the esophagus and potentially cancer-harboring lymph nodes nearby. The remainder of patients could not undergo surgery due to risk or by choice.
A year later, all 10 patients treated through chemotherapy, radiation and surgery remained alive, compared to 58 percent of patients treated with chemotherapy and radiation. After two years, about 83 percent of the patients treated with all three strategies remained alive.
“We’re excited to be able to bring our disciplines together to find solutions for this form of cancer,” said Kemp Kernstine, M.D., Ph.D., director of the Lung Cancer and Thoracic Oncology program and one of the study’s co-authors.
Improvements in care are desperately needed, as one particular form of esophagus cancer is growing more common — and it is usually diagnosed at a late stage, making successful treatment tough.
“Adenocarcinoma is certainly on the rise, related to increased incidence of Barrett’s esophagus in the Western world,” explained Dean Lim, M.D., City of Hope medical oncologist and study co-author. In the Barrett’s esophagus condition, the esophagus changes so that some of its lining becomes like tissue normally found in the intestine.
Barrett’s esophagus usually causes no symptoms itself, but it can sometimes lead to esophageal cancer. It also is associated with the common condition called gastroesophageal reflux disease, or GERD. The risk of adenocarcinoma is 30 to 125 times higher in people who have Barrett's esophagus than it is in others, according to the National Institute of Diabetes and Digestive and Kidney Disorders.
“This is especially being seen with the increasing incidence of GERD, which is seen mostly in obese males,” Lim said.
Other members of the research team included medical oncologist Stephen Shibata, M.D., of the Gastrointestinal Oncology Program, David Smith, Ph.D., of the Department of Biostatistics, and An Liu, Ph.D., Timothy Schultheiss, Ph.D., Richard Pezner, M.D., and Jeffrey Wong, M.D., of the Division of Radiation Oncology.