CAMBRIDGE, Mass. -- An MIT researcher's work on radar technology to detect missiles will be applied in FDA-approved Phase II clinical trials for the treatment of breast cancer. A Phase I clinical trial was completed in July 2000.
In the Phase II trials, more than 100 women will receive focused microwave thermotherapy to heat breast cancer cells to about 115 degrees Fahrenheit, killing them. "This is an out-patient procedure. Patients treated in the Phase I trial went home with only one or two tiny band aids," said Alan J. Fenn, senior staff member in the Air Defense Technology Division at MIT's Lincoln Laboratory. Dr. Fenn invented this new breast cancer treatment technique.
On December 11, 2000, Celsion Corporation (Columbia, Maryland), which exclusively licenses the technology from MIT and is developing the clinical system, announced that it had received FDA approval for two clinical studies using focused microwave thermotherapy for treating breast cancer.
"About ten years ago we were working on radar anti-jamming technology to detect missiles from space-borne satellites," Dr. Fenn explained. In the Strategic Defense Initiative, the main objective was to develop concepts and technology to quickly detect a missile launch, then destroy the missile over the enemy's territory as a deterrent. "As the Cold War was ending and we were asked to look for alternative applications, I discovered that this same focused microwave technology for missile detection could, in theory, be used to treat cancer cells."
It is well established that heat kills cancer cells, but "researchers were having trouble using it to treat cancer deep within the body without burning the skin," Dr. Fenn explained.
In cancer treatment, the main objective is to detect and destroy the cancerous tumor as quickly as possible before it can spread to vital organs. Techniques to detect cancerous tumors are fairly well developed, but treatment techniques such as surgery, chemotherapy and radiation have significant limitations and side effects and do not completely eliminate all the cancer cells.
The focused microwave radiation in the new technique avoids heating the skin, and "heats -- and kills -- cells containing high amounts of water deep in the breast," he said. Breast cancer cells have a high water content -- around 80 percent -- while healthybreast tissue contains only about 20 to 60 percent water.
"Our goal is to destroy all visible and microscopic cancer cells and pre-cancerous cells in the breast," Dr. Fenn said. If this focused microwave thermotherapy can destroy these cells, breast surgery could be reduced or eliminated.
There is the potential to reduce or eliminate conventional radiation to the breast as well. Dr. Fenn noted, however, that if the cancer has spread to other parts of the body, the patient would still need chemotherapy and conventional radiation.
Ten patients were treated in an FDA-approved Phase I safety study, completed in July 2000, in which each patient received a single 20- to 40-minute microwave treatment during which time their breast tumors were heated to about 115 degrees Fahrenheit.
The Phase I study was conducted by Dr. Robert Gardner, MD at Columbia Hospital in West Palm Beach, FL and by Dr. Hernan Vargas, MD at Harbor-UCLA Medical Center in Torrance, CA. The results of the study have been accepted for presentation at the Society of Surgical Oncology Annual Cancer Symposium in March 2001 in Washington, DC. "After seeing the results of the Phase I study, I look forward to beginning the Phase II studies with the ultimate objective of providing breast conserving options to my patients," Dr. Gardner said.
The researchers verified that one to three weeks after a single limited-dose heat-alone treatment, "advanced breast tumors typically had been reduced in size or destroyed by about 50 percent in 8 out of the 10 patients," Dr. Fenn said.
The procedure used two needle probes to sense and measure parameters during treatment, in which the patient lies prone on a treatment table similar to that used in stereotactic breast needle biopsies. "This is an out-patient procedure, " Dr. Fenn said.
Side effects from thermotherapy were minimal. The only significant effect noted was a slight fever a few days following treatment.
Two Phase II clinical trials are planned to be conducted at Columbia Hospital (Florida), UCLA Medical Center (California), Massachusetts General Hospital, Hammersmith Hospital (London) and two other hospitals and will recruit patients who will be treated for advanced or early-stage breast cancer. The purpose of the Phase II clinical trials is to demonstrate the effectiveness of the treatment.
Patients with advanced breast cancer are sometimes treated with preoperative chemotherapy to reduce the tumor size, with the result that about 30 percent of the patients can be converted from mastectomy to breast conservation therapy (lumpectomy plus radiation) for an improved cosmetic result. However, viable tumor cells remain in the breast in about 75 percent of chemotherapy patients.
"With focused microwave thermotherapy, we want to demonstrate a significantly higher rate of conversion from mastectomy to breast conservation therapy as well as a more complete destruction of the cancer cells in the breast," Dr. Fenn said.
One Phase II trial involves approximately 90 patients with advanced breast cancer who desire breast conservation therapy and currently are candidates for mastectomy. They will receive preoperative chemotherapy and three heat treatments, to attempt to reduce the breast tumor size prior to surgery. The control will be patients receiving only preoperative chemotherapy.
In a second Phase II trial, approximately 40 patients with early-stage breast cancer will receive one or two heat-alone treatments to attempt to completely destroy the breast tumor prior to breast conservation therapy. "This study is intended to demonstrate the potential use of thermotherapy to reduce breast surgery," Dr. Fenn said.
The original MIT Lincoln Laboratory research was funded by the Department of the Air Force. Dr. Fenn has received several United States and foreign patents assigned to MIT on the technology.
