Longer Life Expectancy for Cancer Patients Treated with IORT

December 19, 2006

European Medical Studies: Shorter Treatment Cycles, Improved Tumor Control and Longer Life Expectancy for Cancer Patients Treated with IOERT

Intraoperative Electron-Beam Radiation Therapy (IOERT) may soon shorten treatment cycles from 5-7 weeks to 2 minutes for some breast cancer patients and increase survival rates for rectal, pancreatic and sarcoma cancer patients.

December 19, 2006 10:29 AM Eastern Standard Time

SUNNYVALE, Calif.–(BUSINESS WIRE) IntraOp Medical Corporation (OTCBB: IOPM) today announced the results of several cancer research studies that were presented at the European Society of Surgical Oncology (ESSO) Conference, November 30 to December 3 in Venice, Italy, by members of the International Society of Intraoperative Radiation Therapy (ISIORT).

These studies examined the efficacy of intraoperative electron-beam radiation therapy (IOERT) for the treatment of breast cancer, rectal cancer, pancreatic cancer and sarcomas for patients treated at various European centers. The results of individual studies were ‘pooled’ by ISIORT to provide greater statistical significance to the results of individual studies with patients that were treated with identical therapies. Some of the studies are still ongoing but preliminary results show significant improvements in areas such as local tumor control, shorter treatment cycles and longer life expectancy. The studies are summarized below:

Breast Cancer: Two Minutes of IOERT to Replace Five Weeks of Radiation Therapy

The European Institute of Oncology (EIO) is conducting a randomised trial on IOERT for early stage breast cancer. The EIO is testing whether for a select group of women with early stage breast cancer if the conventional treatment of five to seven weeks of external beam radiation, after the woman has healed from the surgical removal of the tumor, can be replaced by a two minute treatment of IOERT. The study is focusing on women over the age of 48 with small tumors and negative nodes.

The report on this study was given by Dr. Giovanni Ivaldi, radiation oncologist at the EIO. The study is expected to be completed by the end of this year and the final results will be reported in about 24 months, after the data has matured. Dr. Ivaldi reported on the results of 590 patients treated with IOERT as the sole radiation treatment for early stage breast cancer at the EIO. The patients treated with IOERT and surgery alone appeared to be doing as well as conventionally treated patients but, it will be another 24 months before all of the answers concerning this promising approach will be proven by the randomized trial.

Intraoperative radiotherapy is becoming a substantial component of the methods and procedures for the treatment of cancer

Dr. Umberto Veronesi, director of the EIO in Milan, Italy, said, “Intraoperative radiotherapy is becoming a substantial component of the methods and procedures for the treatment of cancer because of the new mobile linear accelerators. They are very easy to use. Now, breast cancer, abdominal tumors, rectal cancer, pancreatic cancer, cervical cancer and gynecological tumors can be treated intraoperatively. This represents a new course in therapy.”

Rectal Cancer: Five-Year Survival Rates Increase from 25% to 60% with IOERT

At Catharina Hospital, in Eindhoven, The Netherlands, Dr. Harm Rutten, surgical oncologist, is heading the pooled analysis study for patients with locally advanced rectal cancer. This study showed that patients treated with IOERT achieved a five-year local control of 87% and had a five-year survival of over 60%. This is in marked contrast to conventional treatment approaches without IOERT that typically achieve a five-year local tumor control of less than 50% and survival of only about 25%. Patients who fail to achieve local tumor control in rectal cancer may require further surgery, additional hospitalization and alternative treatments.

According to Dr. Rutten, the results of this study, which pooled the data from four institutions and more than 600 patients, show the important role that IOERT plays in both local control and in survival for advanced rectal disease. “In The Netherlands, we are already writing protocols which require IOERT to be given to all Dutch patients who have rectal recurrences. Recurrent rectal cancer is even a more difficult disease to treat than locally advanced rectal cancer. With the new mobile IOERT technology available, it is convenient and easy to deliver. It should not be long before all major cancer centers can offer this critical treatment to their patients,” said Dr. Rutten.

Breast Cancer: IOERT ‘Boost’ Achieves 99.6% Tumor Control

Dr. Felix Sedlmayer, professor and chairman of radiation oncology at the University of Salzburg, Austria, presented pooled data for 1100 early stage breast cancer patients from six European centers treated using IOERT as a ‘boost’. In a boost treatment, IOERT is given during the time of surgery after the removal of a cancerous tumor and additional external beam radiation is given to the patient after healing from the initial surgery. The advantage of the IOERT boost, also known as the ‘bio-boost’, is that it can be given to all women who are candidates for breast conserving therapy, irrespective of age or nodal status, size or even grade of the tumor. More than half of the women in the pooled analysis had one or more of these adverse factors. With a median follow-up of 53 months, there were no recurrences at the site of the IOERT boost and only four in-breast recurrences resulting in in-breast tumor control of 99.6%. At the University of Salzburg, the bio-boost is already the standard of care for early stage breast cancer patients.

Sarcomas: Shorter Treatment Cycles, Fewer Complications and Longer Survival Rates with IOERT

 

IOERT has the advantage of being delivered at the time of surgery when the boost dose is more effective, is very uniform and can reduce the amount of external radiation therapy that is required.

Dr. Robert Krempien, professor and chairman of radiation oncology at the University of Heidelberg, Germany, presented the results of a study on 255 patients with extremity sarcomas. In this study, radiation therapy combined with surgery (to remove the tumor) was used to avoid surgical amputation of the effected limb. Sarcomas are typically quite large and while they can be treated with external beam radiation or brachytherapy, IOERT has the advantage of being delivered at the time of surgery when the boost dose is more effective, is very uniform and can reduce the amount of external radiation therapy that is required. With a median follow-up of 61 months, Dr. Krempien reported local control and survival rate of 77% and 78% respectively. These results compare quite favorably with conventional boost techniques.

Dr. Krempien also reported on the use of IOERT to treat 123 retroperitoneal sarcoma patients. These sarcomas are large tumors in the abdomen. It is very difficult to achieve local control and long-term survival in patients with this disease. Of the patients in the study, two-thirds had recurrent tumors, 67% were high grade tumors (more virulent) and more than half the patients had tumors larger than 10 cm. Despite these unfavorable characteristics, the analysis showed a five-year survival of 58%, which compares very favorably to conventional approaches for this tumor type.

Pancreatic Cancer: 73% Five-Year Local Control Rates for Patients Treated with Preoperative Chemoradiation Coupled with IOERT

Dr. Vincenzo Valentini, professor of radiation oncology at the Catholic University in Rome, presented the pooled analysis for pancreatic cancer, one of the most difficult cancers to treat effectively, by any method. (In the United States, there are 30,000 cases of pancreatic cancer each year and the annual death rate from this disease is approximately 29,100.) The 185 patients in the European study were treated by three different IOERT techniques: IOERT alone; IOERT followed by post-operative radiation therapy with or without chemotherapy, or pre-operative chemoradiation therapy followed by IOERT. The five-year local control for all patients was 23%, but increased to 58% for patients who also received chemotherapy and was 73% for those who received pre-operative chemoradiation therapy plus IOERT. In pancreatic cancer, patients that achieve local control generally also have pain relief for most of their lives. The five-year survival was 22% for patients that received pre-operative chemoradiation therapy but only 6% for those that had IOERT alone. The pooled analysis clearly demonstrates that the preferred approach for treating pancreatic cancer is preoperative chemoradiation therapy followed by IOERT.

More information on these studies can be found on the ISIORT website, www.isiort.org


Forward-Looking Statements

This press release may contain “forward-looking statements” within the meaning of Section 27A of the 1933 Securities Act and Section 21E of the 1934 Securities Exchange Act. Actual results could differ materially, as the result of such factors as competition in the markets for the company’s products and services and the ability of the Company to execute its plans. By making these forward-looking statements, the Company can give no assurances that transactions described in this press release will be successfully completed, and undertakes no obligation to update these statements for revisions or changes after the date of this press release.